12th Standard Physics Question papers - study material, free online tests, previous year question papers, answer keys, topper answers, centum question paper, exam tips

12th Standard Physics English Medium - Important 5 Mark Question Paper and Answer Key 2022 - 2023 - by Study Materials - Dec 31, 2022 - View & Read

1)
Calculate the electric field due to a dipole on its axial line and equatorial plane.
2)
Obtain the expression for energy stored in the parallel plate capacitor.
3)
Explain the equivalent resistance of a series and parallel resistor network.
4)
Explain the determination of unknown resistance using meter bridge.
5)
Show that for a straight conductor, the magnetic field
\(\overset { \rightarrow }{ B } =\frac { { \mu }_{ ° }I }{ 4\pi a } (cos\varphi _{ 1 }-cos\varphi _{ 2 })\hat { n } \)
\(=\frac { { \mu }_{ ° }I }{ 4\pi a } (sin{ \theta }_{ 1 }+sin{ \theta }_{ 2 })\hat { n } \)

12th Standard Physics English Medium - Important 3 Mark Question Paper and Answer Key 2022 - 2023 - by Study Materials - Dec 31, 2022 - View & Read

1)
Consider two point charges q₁ and q₂ at rest as shown in the figure.

They are separated by a distance of 1m. Calculate the force experienced by the two charges for the following cases:
(a) q₁ = +2μC and q₂ = +3μC
(b) q₁ = +2μC and q₂ = -3μC
(c) q₁= +2μC and q₂ = -3μC kept in water (ε_r = 80)
2)
A spark plug in a bike or a car is used to ignite the air-fuel mixture in the engine. It consists of two electrodes separated by a gap of around 0.6 mm gap as shown in the figure.

To create the spark, an electric field of magnitude 3 x 10⁶ Vm^-1 is required.
(a) What potential difference must be applied to produce the spark?
(b) If the gap is increased, does the potential difference increase, decrease or remains the same?
(c) find the potential difference if the gap is 1 mm.
3)
A battery of voltage V is connected to 30 W bulb and 60 W bulb as shown in the figure.
(a) Identify brightest bulb
(b) which bulb has greater resistance?
(c) Suppose the two bulbs are connected in series, which bulb will glow brighter?
4)
Three identical lamps each having a resistance R are connected to the battery of emf ε as shown in the figure.

Suddenly the switch S is closed.
(a) Calculate the current in the circuit when S is open and closed
(b) What happens to the intensities of the bulbs A, B, and C.
(c) Calculate the voltage across the three bulbs when S is open and closed
(d) Calculate the power delivered to the circuit when S is opened and closed
(e) Does the power delivered to the circuit decrease, increase or remain same?
5)
A proton moves in a uniform magnetic field of strength 0.500 T magnetic field is directed along the x - axis. At initial time, t = 0s, the proton has velocity
\(\hat { v } =(1.95\times { 10 }^{ -5 }\hat { i } +2.00\times { 10 }^{ 5 }\hat { k } )m{ s }^{ -1 }\). Find
(a) At initial time, what is the acceleration of the proton.
(b) Is the path circular or helical? If helical, calculate the radius of helical trajectory and also calculate the pitch of the helix (Note: Pitch of the helix is the distance travelled along the helix axis per revolution).

12th Standard Physics English Medium - Important 2 Mark Question Paper and Answer Key 2022 - 2023 - by Study Materials - Dec 31, 2022 - View & Read

1)
Consider the charge configuration as shown in the figure. Calculate the electric field at point A. If an electron is placed at points A, what is the acceleration experienced by this electron? (mass of the electron = 9.1 x 10^-31 kg and charge of electron = −1.6 x 10^-19C)
2)
The following pictures depict electric field lines for various charge configurations.

(i) In figure (a) identify the signs of two charges and find the ratio \(\left| \frac { { q }_{ 1 } }{ { q }_{ 2 } } \right| \)
(ii) In figure (b), calculate the ratio of two positive charges and identify the strength of the electric field at three points A, B, and C
(iii) Figure (c) represents the electric field lines for three charges. If q₂ = -20 nC, then calculate the values of q₁ and q₃.
3)
A copper wire of cross-sectional area 0.5 mm² carries a current of 0.2 A. If the free electron density of copper is 8.4 x 10²⁸m^-3 then compute the drift velocity of free electrons.
4)
For the given circuit find the value of I.
5)
Calculate the currents in the following circuit.

12th Standard Physics English Medium - Important 1 Mark MCQ's Question Paper and Answer Key 2022 - 2023 - by Study Materials - Dec 31, 2022 - View & Read

1)
What is the ratio of the charges \(\left| \frac { { q }_{ 1 } }{ { q }_{ 2 } } \right| \) for the following electric field line pattern?
2)
A thin conducting spherical shell of radius R has a charge Q which is uniformly distributed on its surface. The correct plot for electrostatic potential due to this spherical shell is _____.
3)
Two metallic spheres of radii 1 cm and 3 cm are given charges of -1 \(\times\) 10^-2 C and 5 \(\times\) 10^-2 C respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is
4)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
5)
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.

12th Standard Physics English Medium - Revision Model Question Paper with Answer Key 2022 - 2023 - by Study Materials - Dec 31, 2022 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
3)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
4)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
5)
A circular coil of radius 5 cm and 50 turns carries a current of 3 ampere. The magnetic dipole moment of the coil is nearly ____.

12th Standard Physics English Medium - Electronics and Communication 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
How does the change in temperature and application of electric field affect the behavior of materials and write the range of resistivity for each materials.
2)
Explain and classify transistor as an oscillator.
3)
Explain current transfer characteristics.
4)
Write any two distinguishing features between Insulators, Metals and semiconductors and insulators an the basis of energy band diagrams.
5)
For a BJT, the common - base current gain α = 0.98 and the collector base junction reverse bias saturation I_CU = 0.6μA. This BJT is connected in the common emitter mode and operated in the active region with a base drive current I_D= 20 μA. The collector current I_C for this mode of operating is

12th Standard Physics English Medium - Electronics and Communication 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Explain the ampitude modulation with necessary diagrams.
2)
Explain the basic elements of communication system with the necessary block diagram.
3)
Explain the ground wave propagation and space wave propagation of electromagnetic waves through space.
4)
What do you know about GPS? Write a few applications of GPS.
5)
Give the applications of lCT in mining and agriculture sectors.

12th Standard Physics English Medium - Electronics and Communication 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Give the Schematic representation of valence band, conduction band, and forbidden energy gap and draw energy band structure of
(a) Insulators
(b) Semiconductors
(c) Metals?
2)
What is electronics?
3)
What are the advantages and Limitations of FM?
4)
Write the limitations of AM.
5)
What are the advantages of FM

12th Standard Physics English Medium - Electronics and Communication 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Distinguish between wireline and wireless communication? Specify the range of electromagnetic waves in which it is used.
2)
What do you mean by Internet of Things?
3)
Distinguish between intrinsic and extrinsic semiconductors.
4)
How electron-hole pairs are created in a semiconductor material?
5)
Distinguish between avalanche breakdown and Zener breakdown.

12th Standard Physics English Medium - Electronics and Communication 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Define energy band
2)
Define conduction band.
3)
What is forbidden energy gap?
4)
What is barrier potential?
5)
Define bias voltage.

12th Standard Physics English Medium - Electronics and Communication 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
A transmitting antenna has a height of 40 m and the height of the receiving antenna is 30 m. What is the maximum distance between them for line-of-sight communication? The radius of the earth is 6.4 × 10⁶ m.
2)
Give the factors that are responsible for transmission impairments.
3)
Explain centre frequency or resting frequency in frequency modulation.
4)
What does RADAR stand for?
5)
Define electron motion in a semiconductor.

12th Standard Physics English Medium - Electronics and Communication 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
C, Si and Ge have same no of valence electrons. C is an insulator because energy required to take one electron out from ______________.
2)
By adding _________ impurity in intrinsic semi conductor, p type semiconductor is made. Charge of these p type semiconductor is ____________
3)
Why can't we physically join p-type and n-type semiconductor directly to form a p-n junction?
4)
Which statement is incorrect regarding for p-n junction?
5)
The intrinsic semi-conductor has ______________.

12th Standard Physics English Medium - Electronics and Communication 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
The barrier potential of a silicon diode is approximately, ______.
2)
If a small amount of antimony (Sb) is added to germanium crystal,______.
3)
A forward biased diode is treated as ________________.
4)
If a positive half-wave rectified voltage is fed to a load resistor, for which part of a cycle there will be current flow through the load?
5)
The zener diode is primarily used as ______.

12th Standard Physics English Medium - Wave Optics 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Find the intensity at a point on a screen in Young's double-slit experiment where the interfering waves of equal intensity have a path difference.
\(\text { (i) } \frac{\lambda}{4} \text {, and (ii) } \frac{\lambda}{3}\)
2)
The critical angle for a given piece of glass is 45°. Calculate the polarising angle for it. Also calculate the angle of refraction when light is incident on this glass at an angle of incident equal to i_p.
3)
You are given two converging lenses of focal lengths 1.25 cm and 5 cm to design a compound microscope. If it is desired to have a magnification of 30, find out the separation between the objective and the eyepiece.
4)
The total magnification produced by a compound microscope is 20. The magnification produced by the eyepiece is 5. The microscope is focused on a certain object. The distance between the objective and eyepiece is observed to be 14 cm. If the least distance of distinct vision is 20 cm, calculate the focal length of the objective and the eyepiece.
5)
A small telescope has an objective lens of focal length 150 cm and an eyepiece of focal length of 5 cm. What is the magnifying power of the telescope for viewing the distant objects in normal adjustment?
If this telescope is used to view a 100 m tall tower 3km away, what is the height of the image of the tower formed by the objective lens?

12th Standard Physics English Medium - Wave Optics 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Prove law of reflection using Huygens’ principle.
2)
Prove law of refraction using Huygens’ principle.
3)
Obtain the equation for resultant intensity due to interference of light.
4)
Explain the Young’s double slit experimental setup and obtain the equation for path difference.
5)
Discuss the interference in thin films and obtain the equations for constructive and destructive interference for transmitted and reflected light.

12th Standard Physics English Medium - Wave Optics 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What are the conditions for obtaining clear and broad interference bands?
2)
Discuss diffraction at single slit and obtain the condition for n^th maximum.
3)
What are Airy's discs?
4)
Write the drawbacks of Nicol prism.
5)
What is the difference between resolution and magnification?

12th Standard Physics English Medium - Wave Optics 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Obtain the relation between phase difference and path difference.
2)
Differentiate between Fresnel and Fraunhofer diffraction.
3)
What is Fresnel’s distance? Obtain the equation for Fresnel’s distance.
4)
Mention the differences between interference and diffraction.
5)
Differentiate between polarised and unpolarised light.

12th Standard Physics English Medium - Wave Optics 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What is Rayleigh's scattering?
2)
Write the difference of real and virtual images by a plane mirror.
3)
What is known as constructive interference?
4)
What is known as destructive interference?
5)
Define bandwidth.

12th Standard Physics English Medium - Wave Optics 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What are the salient features of corpuscular theory of light?
2)
What are the important points of wave theory of light?
3)
What is the significance of electromagnetic wave theory of light?
4)
Write a short note on quantum theory of light.
5)
Define wavefront.

12th Standard Physics English Medium - Wave Optics 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
A light bulb is placed between two mirrors (plane) inclined at an angle of 60°. Number of images formed are ________________.
2)
Two plane mirrors are inclined at an angle of no. The number of images of a point object placed between them will be _______________.
3)
To get three images of a single object, one should have two plane mirror at an angle of ______________.
4)
A man of length h requires a mirror of length at least equal to, to see his own complete image is _______________.
5)
Two plane mirrors are at 45° to each other. If an object is placed between them then the number of images will be ________________.

12th Standard Physics English Medium - Wave Optics 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
A plane glass is placed over a various coloured letters (violet, green, yellow, red) The letter which appears to be raised more is _____.
2)
Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm approximately. The maximum distance at which these dots can be resolved by the eye is_____. [take wavelength of light, λ = 500 nm]
3)
In a Young’s double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to, _____.
4)
Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are _____.
5)
When light is incident on a soap film of thickness 5 x 10^–5 cm, the wavelength of light reflected maximum in the visible region is 5320 Å. Refractive index of the film will be, _____.

12th Standard Physics English Medium - Recent Developments in Physics 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Write the advantages and disadvantages of robotic.
2)
Explain the interdisciplinary nature of nanotechnology.
3)
What are the disadvantages of Robotics?
4)
Write the advantages of Robotics than the human.
5)
Can we completely replace humans with robots?

12th Standard Physics English Medium - Recent Developments in Physics 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Discuss the applications of Nanomaterials in various fields.
2)
What are the possible harmful effects of usage of Nanoparticles? Why?

12th Standard Physics English Medium - Recent Developments in Physics 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Write the application of nano robots in medical field?
2)
What is particle physics?
3)
Write the two ways of preparing the nano materials.
4)
Write the aim of artificial intelligence in robots.
5)
What is robotics?

12th Standard Physics English Medium - Recent Developments in Physics 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Distinguish between Nanoscience and Nanotechnology.
2)
What is the difference between Nano materials and Bulk materials?
3)
Mention any two advantages and disadvantages of Robotics.
4)
Discuss the functions of key components in Robots?
5)
Elaborate any two types of Robots with relevant examples.

12th Standard Physics English Medium - Recent Developments in Physics 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What is nanotechnology?
2)
What is the two important phenomena that govern the nano particles?
3)
How does the peacock feathers get colouration?
4)
How does the manipulation of colours obtain in nanoscale structure?
5)
What is the role of nanostructure in the morpho butterfly wings?

12th Standard Physics English Medium - Recent Developments in Physics 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Give any two examples for “Nano” in nature.
2)
Why steel is preferred in making Robots?
3)
What are black holes?
4)
What are sub atomic particles?

12th Standard Physics English Medium - Recent Developments in Physics 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Nanoscience is the science of object with typical sizes of ___________
2)
If the particle of a solid is of size less than 100 nm, it is said to be a ____________
3)
__________ Scanning Electron Micrograph (SEM) showing the nano structures on the surface of a leaf from a lotus plant
4)
_______ is synthesized top down approach
5)
Best example for applications of nanotechnology is ______________.

12th Standard Physics English Medium - Recent Developments in Physics 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
The particle size of ZnO material is 30 nm. Based on the dimension it is classified as _____.
2)
Which one of the following is the natural nanomaterial.
3)
The blue print for making ultra durable synthetic material is mimicked from _____.
4)
The method of making nanomaterial by assembling the atoms is called _____.
5)
“Sky wax” is an application of nano product in the field of _____.

12th Standard Physics English Medium - Atomic and Nuclear Physics 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Explain the results of Rutherford α-particle scattering experiment.
2)
What are the drawbacks of Rutherford atom model?
3)
Write the application of alpha decay in smoke detectors.
4)
Explain Chain reaction.
5)
The half-life of \(_{ 38 }^{ 90 }{ Sr }\) is 28 years. What is the disintegration rate of 15 mg of this isotope?

12th Standard Physics English Medium - Atomic and Nuclear Physics 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Explain the J.J. Thomson experiment to determine the specific charge of electron.
2)
Discuss the Millikan’s oil drop experiment to determine the charge of an electron.
3)
Derive the energy expression for an electron is the hydrogen atom using Bohr atom model.
4)
Discuss the spectral series of hydrogen atom.
5)
Explain the variation of average binding energy with the mass number using graph and discuss about its features.

12th Standard Physics English Medium - Atomic and Nuclear Physics 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What does a neutron moderator do?
2)
Write the properties of neutrino?
3)
What is the diameter of H₂ atom?
4)
Show that the decay rate 'R' of a sample of a radionuclide is related to the number of radioactive nuclei 'N' at the same instant by the expression R = λN.
5)
Digine atomic mass unit. Find its energy equivalent in MeV

12th Standard Physics English Medium - Atomic and Nuclear Physics 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Write the properties of cathode rays.
2)
Give the results of Rutherford alpha scattering experiment.
3)
Write down the postulates of Bohr atom model.
4)
(a) A hydrogen atom is excited by radiation of wavelength 97.5 nm. Find the principal quantum number of the excited state
(b) Show that the total number of lines in emission spectrum is \(\frac { n(n-1) }{ 2 } \) Compute the total number of possible lines in emission spectrum as given in(a).
5)
Calculate the radius of the earth if the density of the earth is equal to the density of the nucleus.[mass of earth 5.97 x 10²⁴ kg].

12th Standard Physics English Medium - Atomic and Nuclear Physics 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Which ray has high ionising power? Why?
2)
What is meant by fissile material? Give an example for fissile material?
3)
What is nuclear chain reaction?
4)
State the reasons. Why a chain reaction stops?
5)
What are the essential parts of a nuclear reactor?

12th Standard Physics English Medium - Atomic and Nuclear Physics 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What are cathode rays?
2)
What is meant by excitation energy?
3)
Define the ionization energy and ionization potential.
4)
Write down the draw backs of Bohr atom model.
5)
What is distance of closest approach?

12th Standard Physics English Medium - Atomic and Nuclear Physics 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Bohr's postulate is based on _______________.
2)
The circumference of an electron's orbit of radius r must be an integral multiple of de Broglie wavelength that is ________________.
3)
The ground state energy of a hydrogen atom is 13.6 eV. The energy needed to ionize H₂ atom from its second excited state ______________.
4)
In terms of Bohr radius a₀, the radius of the third Bohr orbit of a hydrogen atom is given by ______________.
5)
The ionization energy of hydrogen atom is -13.6e V. The energy corresponding to a transition between 3rd and 4th orbit is ______________.

12th Standard Physics English Medium - Atomic and Nuclear Physics 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Suppose an alpha particle accelerated by a potential of V volt is allowed to collide with a nucleus of atomic number Z, then the distance of closest approach of alpha particle to the nucleus is _____.
2)
In a hydrogen atom, the electron revolving in the fourth orbit, has angular momentum equal to _____.
3)
Atomic number of H-like atom with ionization potential 122.4 V for n = 1 is _____.
4)
The ratio between the radius of first three orbits of hydrogen atom is _____.
5)
The charge of cathode rays particle is _____.

12th Standard Physics English Medium - Dual Nature of Radiation and Matter 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Explain the production of x-rays.
2)
Write a note on continuous x-ray spectra.
3)
Determine the distance of closed approach when an alpha particle of kinetic energy 4.5 MeV strikes a nucleus of Z = 80, stops and reverses its direction.
4)
A 12.3 eV electron beam is used to bombard gaseous hydrogen at room temperature. Upto which energy level the hydrogen atoms would be excited? Calculate the wavelengths of the second member of Lyman series and second member of Balmer series.

12th Standard Physics English Medium - Dual Nature of Radiation and Matter 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What do you mean by electron emission? Explain briefly various methods of electron emission.
2)
Briefly discuss the observations of Hertz, Hallwachs and Lenard.
3)
Explain the effect of potential difference on photoelectric current.
4)
Explain how frequency of incident light varies with stopping potential.
5)
Explain why photoelectric effect cannot be explained on the basis of wave nature of light.

12th Standard Physics English Medium - Dual Nature of Radiation and Matter 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Derive an expression for De Broglie wave length.
2)
(a) Define the term 'intensity of radiation' in terms of photon picture of light.
(b) Two monochromatic beams, one red and the other blue; have the same intensity. In which case
(i) the number of photons per unit area per second is larger,
(ii) the maximum kinetic energy of the photoelectrons is more? Justify you answer.
3)
List out the laws of photoelectric effect. (or) Write any three Laws of Photoelectric Effect
4)
A proton and an electron have same velocity. Which one has greater de Broglie wavelength and why?
5)
When the electron orbiting in a hydrogen atom in its ground state moves to the third excited state, show how the de Broglie wavelength associated with it would be affected?

12th Standard Physics English Medium - Dual Nature of Radiation and Matter 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What is a photo cell? Mention the different types of photocells.
2)
Name an experiment that shows the wave nature of the electron. Which phenomenon was observed in this experiment using an electron beam?
3)
List out the laws of photo electric effect.
4)
A 150 W lamp emits light of mean wavelength of 5500 Å. If the efficiency is 12%, find out the number of photons emitted by the lamp in one second.
5)
How many photons of frequency 10¹⁴ Hz will make up 19.86 J of energy?

12th Standard Physics English Medium - Dual Nature of Radiation and Matter 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What is surface barrier?
2)
Give example for photosensitive materials Why is called so?
3)
What is photo emissive cell?
4)
What is photo voltaic cell?
5)
What is photo conductive cell?

12th Standard Physics English Medium - Dual Nature of Radiation and Matter 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Why do metals have a large number of free electrons?
2)
Define work function of a metal. Give its unit.
3)
What is photoelectric effect?
4)
How does photocurrent vary with the intensity of the incident light?
5)
Give the definition of intensity of light according to quantum concept and its unit.

12th Standard Physics English Medium - Dual Nature of Radiation and Matter 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
P and E denote the linear momentum and energy of a photon. If the wavelength is decreased ____________.
2)
The work function of a metal is hv₀. Light of frequency v falls on this metal. The photoelectric effect will take place only if ___________.
3)
When stopping potential is applied in an experiment on the photoelectric effect no photocurrent is observed. This means that ______________.
4)
If the frequency of light in a photo electron experiment is doubled the stopping potential will ______________.
5)
Light of wavelength falls on a metal having work function \(\frac { { h }_{ c } }{ { \lambda }_{ 0 } } \). Photo electric effect will place only if __________.

12th Standard Physics English Medium - Dual Nature of Radiation and Matter 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
The wavelength λ_eof an electron and λ_p of a photon of same energy E are related by _____.
2)
In an electron microscope, the electrons are accelerated by a voltage of 14 kV. If the voltage is changed to 224 kV, then the de Broglie wavelength associated with the electrons would _____.
3)
The wave associated with a moving particle of mass 3 x 10^–6 g has the same wavelength as an electron moving with a velocity 6 x 10⁶ ms^-1. The velocity of the particle is _____.
4)
When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential is \(\frac{V}{4}\). The threshold wavelength for the metallic surface is _____.
5)
If a light of wavelength 330 nm is incident on a metal with work function 3.55 eV, the electrons are emitted. Then the wavelength of the wave associated with the emitted electron is _____.(Take h = 6.6 x 10^–34 Js)

12th Standard Physics English Medium - Ray Optics 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Obtain lens maker’s formula and mention its significance.
2)
Derive the equation for effective focal length for lenses in out of contact
3)
The focal length of an equiconvex lens is equal to the radius of curvature of either face. What is the value of refractive index of the material of the lens?
4)
A ray of light falls on a transparent sphere with centre C as shown in the figure. The ray emerges from the sphere paralled to the line AB. Find the angle of refraction at A if refraction index of the material of the sphere is \(\sqrt { 3 } \).
5)
For the same angle of incidence, the angle of refraction in two media A and Bare 25° and 35° respectively. In which one of the two media is the speed of light lesser?

12th Standard Physics English Medium - Ray Optics 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Derive the mirror equation and the equation for lateral magnification.
2)
Describe the Fizeau’s method to determine the speed of light.
3)
Obtain the equation for radius of illumination (or) Snell’s window.
4)
Derive the equation for acceptance angle and numerical aperture of optical fibre.
5)
Obtain the equation for lateral displacement of light passing through a glass slab.

12th Standard Physics English Medium - Ray Optics 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
State the laws of reflection
2)
What is intensity division?
3)
Obtain the equation for of microscope.
4)
Write the conditions for nature of objects and images.
5)
What is principal axis of the mirror?

12th Standard Physics English Medium - Ray Optics 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What is optical path? Obtain the equation for optical path.
2)
State the laws of reflection.
3)
Obtain the equation for apparent depth.
4)
What are critical angle and total internal reflection?
5)
Obtain the equation for critical angle.

12th Standard Physics English Medium - Ray Optics 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What is angle of deviation due to reflection?
2)
Is it possible for two lenses to produce zero power?
3)
What is reflection?
4)
What is meant by concave and convex mirror?
5)
Define centre of curvature.

12th Standard Physics English Medium - Ray Optics 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
What is angle of deviation due to refraction?
2)
What is principle of reversibility?
3)
What is relative refractive index?
4)
Why do stars twinkle?
5)
Explain the reason for the glittering of diamond.

12th Standard Physics English Medium - Ray Optics 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
A light bulb is placed between two mirrors (plane) inclined at an angle of 60°. Number of images formed are ________________.
2)
Two plane mirrors are inclined at an angle of no. The number of images of a point object placed between them will be _______________.
3)
To get three images of a single object, one should have two plane mirror at an angle of ______________.
4)
A man of length h requires a mirror of length at least equal to, to see his own complete image is _______________.
5)
Two plane mirrors are at 45° to each other. If an object is placed between them then the number of images will be ________________.

12th Standard Physics English Medium - Ray Optics 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
The speed of light in an isotropic medium depends on, ______.
2)
A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is, ______.
3)
An object is placed in front of a convex mirror of focal length off and the maximum and minimum distance of an object from the mirror such that the image formed is real and magnified.
4)
For light incident from air on a slab of refractive index 2, the maximum possible angle of refraction is, ______.
5)
If the velocity and wavelength of light in air is V_a and λ_a and that in water is V_w and λ_w, then the refractive index of water is______.

12th Standard Physics English Medium - Electromagnetic Waves 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Show how to generalize Ampere's circuital law to include the term due to displacement current?
2)
A parallel plate capacitor is charged by an external ac source straight the displacement current inside the capacitor is the same as the current charging the capacitor.
3)
In an Electromagnetic wave propagating along the X - direction, the magnetic field oscillates at a frequency. 5 x 10⁸ Hz and has an amplitude of 10^-7 tesla, acting along the Y-direction.
(i) What is the wavelength of the wave?
(ii) Write the expression representing the corresponding oscillating electric field.
4)
The oscillating magnetic field in a plane Electromagnetic wave is given by
B = (8 x 10^-6) sin (2 x 10¹¹t + 300 πx) T
(i) Calculate the λ of Electromagnetic wave.
(ii) Find the amplitude of electric field.
5)
In a plane Electromagnetic wave, the electric field oscillates sinusoidally at a frequency of 1.5 x 10¹⁰Hz with & an amplitude of 36 Vm^-1.
(i) What is the wavelength of a wave?
(ii) What the amplitude of the oscillating magnetic field?
(iii) Straight the average energy density of the electric field \(\left( \overrightarrow { E } \right) \), is equal to average energy density of the magnetic field \(\left( \overrightarrow { B } \right) \)

12th Standard Physics English Medium - Electromagnetic Waves 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Write down Maxwell equations in integral form.
2)
Explain the Maxwell’s modification of Ampere’s circuital law.
3)
Discuss the source of electromagnetic waves.
4)
Explain the types of emission spectrum.
5)
Explain the types of absorption spectrum.

12th Standard Physics English Medium - Electromagnetic Waves 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Discuss briefly the experiment conducted by Hertz to produce and detect electromagnetic spectrum.
2)
Write an expression for the momentum of Electromagnetic wave.
3)
Write the uses of Infrared radiation
4)
Write the frequency source of production and uses of Ultraviolet radiation.
5)
Write the production of gamma rays and mention its properties and uses.

12th Standard Physics English Medium - Electromagnetic Waves 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Consider a parallel plate capacitor which is connected to an 230 V RMS value and 50 Hz frequency. If the separation distance between the plates of the capacitor and area of the plates are 1 mm and 20 cm² respectively. Calculate the displacement current at t = 1 s.
2)
A magnetron in a microwave oven emits electromagnetic waves (em waves) with frequency f = 2450 MHz. What magnetic field strength is required for electrons to move in circular paths with this frequency?
3)
A pulse of light of duration 10⁻⁶s is absorbed completely by a small object initially at rest. If the power of the pulse is 60\(\times\) 10⁻³ W. Calculate the final momentum of the object.
4)
Let an electromagnetic wave propagate along the x-direction, the magnetic field oscillates at a frequency of 10¹⁰ Hz and has an amplitude of 10⁻⁵ T, acting along the y-direction. Then, compute the wavelength of the wave. Also write down the expression for electric field in this case.
5)
If the relative permeability and relative permittivity of a medium are 1.0 and 2.25 respectively, find the speed of the electromagnetic wave in this medium.

12th Standard Physics English Medium - Electromagnetic Waves 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Explain the concept of intensity of electromagnetic waves.
2)
What is meant by Fraunhofer lines?
3)
Write the uses of Radio waves.
4)
Write the uses of Micro waves.
5)
(i) How is the speed of Electromagnetic waves in vacuum determined by the electric and magnetic fields? and
(ii) Do Electromagnetic waves carry energy and momentum?

12th Standard Physics English Medium - Electromagnetic Waves 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
The relative magnetic permeability of the medium is 2.5 and the relative electrical permittivity of the medium is 2.25. Compute the refractive index of the medium.
2)
Compute the speed of the electromagnetic wave in a medium if the amplitude of electric and magnetic fields are 3 x 10⁴N C^–1 and 2 x 10^–4 T, respectively.
3)
What is displacement current?
4)
What are electromagnetic waves?
5)
Write down the integral form of modified Ampere’s circuital law.

12th Standard Physics English Medium - Electromagnetic Waves1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
During the propagation of electromagnetic waves in a medium __________________.
2)
A radiation of energy E falls normally on a perfectly reflecting surface. Th e momentum transferred to the surface __________________.
3)
Who produced the electromagnetic waves first?
4)
Speed of electromagnetic wave is the same for all ______________.
5)
Electromagnetic waves are produced by _____________.

12th Standard Physics English Medium - Electromagnetic Waves 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
The dimension of \(\frac { 1 }{ { \mu }_{ 0 }{ \varepsilon }_{ 0 } } \) is _____.
2)
If the amplitude of the magnetic field is 3 x 10⁻⁶ T, then amplitude of the electric field for a electromagnetic waves is _____.
3)
Which of the following electromagnetic radiations is used for viewing objects through fog
4)
Which of the following is false for electromagnetic waves
5)
Consider an oscillator which has a charged particle oscillating about its mean position with a frequency of 300 MHz. The wavelength of electromagnetic waves produced by this oscillator is _____.

12th Standard Physics English Medium - Electromagnetic Induction and Alternating Current 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Using Faraday’s law of electromagnetic induction, derive an equation for motional emf.
2)
Show that the total energy is constant druing LC oscillations.
3)
Derive a relation between mean or average value of AC and its peak value.
4)
Derive an expression for the RMS value of AC.
5)
Define RMS value of AC. Derive a relation between RMS value of AC voltage & maximum voltage.

12th Standard Physics English Medium - Electromagnetic Induction and Alternating Current 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Establish the fact that the relative motion between the coil and the magnet induces an emf in the coil of a closed circuit.
2)
Give an illustration of determining direction of induced current by using Lenz’s law.
3)
Show that Lenz’s law is in accordance with the law of conservation of energy.
4)
Give the uses of Foucault current.
5)
Define self-inductance of a coil interms of
(i) magnetic flux and
(ii) induced emf.

12th Standard Physics English Medium - Electromagnetic Induction and Alternating Current 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Distinguish between average & rms value of an AC.
2)
What is Phasort and How to draw phasor diagram.
3)
What is the phase relationship between current & voltage in an inductive? Draw
(i) Phosor diagram and
(ii) wave diagram.
4)
How does the capacitive reactance depend on frequency? & What is the reactance of a capacitor at hertz to the study at?
5)
What is the phase relation between current and emf in an AC circuit containing a cpacitor only? Sketch a graph showing the variation the reactance of a capacitor with frequency.

12th Standard Physics English Medium - Electromagnetic Induction and Alternating Current 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
A circular loop of area 5 x 10^–2 m² rotates in a uniform magnetic field of 0.2T. If the loop rotates about its diameter which is perpendicular to the magnetic field as shown in figure. Find the magnetic flux linked with the loop when its plane is
(i) normal to the field
(ii) inclined 60^o to the field and
(iii) parallel to the field.
2)
A conducting rod of length 0.5 m falls freely from the top of a building of height 7.2 m at a place in Chennai where the horizontal component of Earth’s magnetic field is 4.04 × 10^–5 T. If the length of the rod is perpendicular to Earth’s horizontal magnetic field, find the emf induced across the conductor when the rod is about to touch the ground. (Assume that the rod falls down with constant acceleration of 10 m s^–2)
3)
A solenoid of 500 turns is wound on an iron core of relative permeability 800. The length and radius of the solenoid are 40 cm and 3 cm respectively. Calculate the average emf induced in the solenoid if the current in it changes from 0 to 3 A in 0.4 second.
4)
Consider two coplanar, co-axial circular coils A and B as shown in figure. The radius of coil A is 20 cm while that of coil B is 2 cm. The number of turns in coils A and B are 200 and 1000 respectively. Calculate the mutual inductance between the coils. If the current in coil A changes from 2 A to 6 A in 0.04 s, determine the induced emf in coil B and the rate of change of flux through the coil B at that instant.
5)
A circular metal of area 0.03 m² rotates in a uniform magnetic field of 0.4 T. The axis of rotation passes through the centre and perpendicular to its plane and is also parallel to the field. If the disc completes 20 revolutions in one second and the resistance of the disc is 4 Ω, calculate the induced emf between the axis and the rim and induced current flowing in the disc.

12th Standard Physics English Medium - Electromagnetic Induction and Alternating Current 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Draw graphs showing the distribution of charge in a capacitor and current through an inductor during LC oscillations with respect to time. Assume that the charge in the capacitor is maximum initially.
2)
Define Magnetic Flux.
3)
What is meant by power transmission?
4)
Explain the use of transformers in long distance transmission of electric power.
5)
What is meant by AC vollage?

12th Standard Physics English Medium - Electromagnetic Induction and Alternating Current 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
A circular antenna of area 3 m² is installed at a place in Madurai. The plane of the area of antenna is inclined at 47^o with the direction of Earth’s magnetic field. If the magnitude of Earth’s field at that place is 4.1 x 10^–5 T find the magnetic flux linked with the antenna.
2)
A cylindrical bar magnet is kept along the axis of a circular solenoid. If the magnet is rotated about its axis, find out whether an electric current is induced in the coil.
3)
A closed coil of 40 turns and of area 200 cm², is rotated in a magnetic field of flux density 2 Wb m^–2. It rotates from a position where its plane makes an angle of 30^o with the field to a position perpendicular to the field in a time 0.2 s. Find the magnitude of the emf induced in the coil due to its rotation.
4)
A straight conducting wire is dropped horizontally from a certain height with its length along east-west direction. Will an emf be induced in it? Justify your answer.
5)
If the current i flowing in the straight conducting wire as shown in the figure decreases, find out the direction of induced current in the metallic square loop placed near it.

12th Standard Physics English Medium - Electromagnetic Induction and Alternating Current 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
Electromagnetic induction is-not used in ___________________.
2)
Lenz's law is in accordance with the law of ________________.
3)
The unit henry can also be written as ______________.
4)
The self-inductance of a straight conductor is ________________.
5)
An emf of 12V is induced when the current in the coil changes at the rate of 40 A S^-1. The coefficient of self induction of the coil is __________________.

12th Standard Physics English Medium - Electromagnetic Induction and Alternating Current 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 02, 2022 - View & Read

1)
An electron moves on a straight line path XY as shown in the figure. The coil abcd is adjacent to the path of the electron. What will be the direction of current, if any, induced in the coil?
2)
A thin semi-circular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure.

The potential difference developed across the ring when its speed v, is
3)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
4)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
5)
The current i flowing in a coil varies with time as shown in the figure. The variation of induced emf with time would be

12th Standard Physics English Medium - Magnetism and Magnetic Effects of Electric Current 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Consider a circular wire loop of radius R, mass m kept at rest on a rough surface. Let I be the current flowing through the loop and be the magnetic field acting along horizontal as shown in Figure. Estimate the current I that should be applied so that one edge of the loop is lifted off the surface?
2)
Explain the principle and working of a moving coil galvanometer.
3)
Show that the magnetic field at any point on the axis of the solenoid having n turns per unit length is \(B=\frac { 1 }{ 2 } { \mu }_{ ° }nI(cos{ \theta }_{ 1 }-cos{ \theta }_{ 2 })\).
4)
Let I₁ and I₂ be the steady currents passing through a long horizontal wire XY and PQ respectively. The wire PQ is fixed in horizontal plane and the wire XY be is allowed to move freely in a vertical plane. Let the wire XY is in equilibrium at a height d over the parallel wire PQ as shown in figure.

Show that if the wire XY is slightly displaced and released, it executes Simple Harmonic Motion (SHM). Also, compute the time period of oscillations.
5)
Drive an expression of Potential energy of a bar magnet in a uniform magnetic field.

12th Standard Physics English Medium - Magnetism and Magnetic Effects of Electric Current 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Show that for a straight conductor, the magnetic field
\(\overset { \rightarrow }{ B } =\frac { { \mu }_{ ° }I }{ 4\pi a } (cos\varphi _{ 1 }-cos\varphi _{ 2 })\hat { n } \)
\(=\frac { { \mu }_{ ° }I }{ 4\pi a } (sin{ \theta }_{ 1 }+sin{ \theta }_{ 2 })\hat { n } \)
2)
Discuss Earth’s magnetic field in detail.
3)
Deduce the relation for the magnetic field at a point due to an infinitely long straight conductor carrying current using Biot-Savart law.
4)
Obtain a relation for the magnetic field at a point along the axis of a circular coil carrying current using Biot-Savart law.
5)
Compute the torque experienced by a magnetic needle in a uniform magnetic field.

12th Standard Physics English Medium - Magnetism and Magnetic Effects of Electric Current 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Show the time period of oscillation when a bar magnet is kept in a uniform magnetic field is \(T=2\pi \sqrt { \frac { 1 }{ { p }_{ m }B } } \) in second, where I represents a moment of inertia of the bar magnet, p_m is the magnetic moment and B is the magnetic field.
2)
Calculate the magnetic field at a point P which is perpendicular bisector to current carrying straight wire as shown in figure.
3)
What is meant by coercivity?
4)
What are electromagnets? Mention examples.
5)
State Maxwell's right hand cork screw rule?

12th Standard Physics English Medium - Magnetism and Magnetic Effects of Electric Current 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
A short bar magnet has a magnetic moment of 0.5 J T^–1. Calculate magnitude and direction of the magnetic field produced by the bar magnet which is kept at a distance of 0.1 m from the centre of the bar magnet along
(a) axial line of the bar magnet and
(b) normal bisector of the bar magnet.
2)
Consider a magnetic dipole which on switching ON external magnetic field orient only in two possible ways i.e., one along the direction of the magnetic field (parallel to the field) and another anti-parallel to magnetic field. Compute the energy for the possible orientation.
3)
A coil of a tangent galvanometer of diameter 0.24 m has 100 turns. If the horizontal component of Earth’s magnetic field is 25 x 10^–6T then, calculate the current which gives a deflection of 60^o .
4)
Compute the intensity of magnetisation of the bar magnet whose mass, magnetic moment and density are 200 g, 2 A m² and 8 g cm^–3, respectively.
5)
Calculate the magnetic field inside a solenoid, when
(a) the length of the solenoid becomes twice with fixed number of turns
(b) both the length of the solenoid and number of turns are doubled
(c) the number of turns becomes twice for the fixed length of the solenoid.
Compare the results.

12th Standard Physics English Medium - Magnetism and Magnetic Effects of Electric Current 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
What are the causes for earth's magnetic field according to Gover?
2)
What is Geomagnetism?
3)
State the elements of Earth's magnetic field.
4)
What is meant by
(i) Geographic axis
(ii) Geographic meridian &
(iii) Geographic equator?
5)
What is magnetic axis, magnetic meridian & magnetic equator?

12th Standard Physics English Medium - Magnetism and Magnetic Effects of Electric Current 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
The horizontal component and vertical component of Earth’s magnetic field at a place are 0.15 G and 0.26 G respectively. Calculate the angle of dip and resultant magnetic field. (G - gauss, cgs unit for magnetic field 1G = 10^–4T)
2)
Let the magnetic moment of a bar magnet be \(\overset { \rightarrow }{ { p }_{ m } } \) whose magnetic length is d = 2l and pole strength is q_m. Compute the magnetic moment of the bar magnet when it is cut into two pieces
(a) along its length
(b) perpendicular to its length.
3)
Compute the magnetic length of a uniform bar magnet if the geometrical length of the magnet is 12 cm. Mark the positions of magnetic pole points.
4)
Calculate the magnetic flux coming out from closed surface containing magnetic dipole (say, a bar magnet) as shown in figure.
5)
The repulsive force between two magnetic poles in air is 9 x 10^–3 N. If the two poles are equal in strength and are separated by a distance of 10 cm, calculate the pole strength of each pole.

12th Standard Physics English Medium - Magnetism and Magnetic Effects of Electric Current 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
A simple pendulum with charged bob is oscillating with time period T and lets θ be the angular displacement. If the uniform magnetic field switched ON in a direction perpendicular to the plane of oscillation then ___________.
2)
Which of the following graphs shows the variation of magnetic induction B with distance 'r' from along wire carrying current?
3)
Four wires each of length 2m are bent into four loops P, Q, R, and S, and then suspended into a uniform magnetic field as shown in the figure same current is passed in each loop. On which loop the couple will be the highest?
4)
Which one of the following represents current magnetic field lines?
5)
The angle of dip at a place, when horizontal and vertical components of earth's field are equal is ______________.

12th Standard Physics English Medium - Magnetism and Magnetic Effects of Electric Current 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
The magnetic field at the centre O of the following current loop is
2)
An electron moves in a straight line inside a charged parallel plate capacitor of uniform charge density σ. The time taken by the electron to cross the parallel plate capacitor undeflected when the plates of the capacitor are kept under constant magnetic field of induction \((\vec{B})\) is
3)
A particle having mass m and charge q accelerated through a potential difference V. Find the force experienced when it is kept under perpendicular magnetic field \(\vec { B } \).
4)
A circular coil of radius 5 cm and 50 turns carries a current of 3 ampere. The magnetic dipole moment of the coil is nearly ____.
5)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.

12th Standard Physics English Medium - Current Electricity 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
The current through an element is shown in the figure. Determine the total charge that pass through the element at a) t = 0 s, b) t = 2 s, c) t = 5s
2)
Calculate the effect internal resistance in series and parallel.
3)
Explain the variation of resistivity of conductor and semiconductor with change in temperature.
4)
What is potentiometer? Give its constant and 5 principles.
5)
Explain what is
(i) Thomson effect,
(ii) Positive Thomson effect,
(iii) Negative effect.

12th Standard Physics English Medium - Current Electricity 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Describe the microscopic model of current and obtain general form of Ohm’s law.
2)
Obtain the macroscopic form of Ohm’s law from its microscopic form
3)
Explain the equivalent resistance of a series and parallel resistor network.
4)
Explain the determination of the internal resistance of a cell using voltmeter.
5)
State and explain Kirchhoff ’s rules

12th Standard Physics English Medium - Current Electricity 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
What are carbon resistors? What does the colour indicates?
2)
Derive an expression of drift velocity and write the relation between drift velocity and mobility.
3)
How does one can understand the temperature dependence of resistivity of a conductor?
4)
(a) Distinguish between electric cells and batteries.
(b) Explain its function.
5)
What is meant by electromotive force?

12th Standard Physics English Medium - Current Electricity 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Distinguish between drift velocity and mobility.
2)
What are ohmic and non ohmic devices?
3)
The resistance of a wire is 20 Ω. What will be new resistance, if it is stretched uniformly 8 times its original length?
4)
Consider a rectangular block of metal of height A, width B and length C as shown in the figure.

If a potential difference of V is applied between the two faces A and B of the block (figure (a)), the current I_AB is observed. Find the current that flows if the same potential difference V is applied between the two faces B and C of the block (figure (b)). Give your answers in terms of I_AB.
5)
Calculate the equivalent resistance for the circuit which is connected to 24 V battery and also find the potential difference across each resistors in the circuit.

12th Standard Physics English Medium - Current Electricity 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Define current.
2)
Define instantaneous current.
3)
Define Ampere.
4)
Define mean free time \(\tau \).
5)
Why are household appliances connected in parallel?

12th Standard Physics English Medium - Current Electricity 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Compute the current in the wire if a charge of 120 C is flowing through a copper wire in 1 minute.
2)
Why current is a scalar?
3)
State microscopic form of Ohm’s law.
4)
State macroscopic form of Ohm’s law.
5)
Define electrical resistivity.

12th Standard Physics English Medium - Current Electricity 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
The colour code on a carbon resistor is red - red - black. The resistance of the resistor is ___________.
2)
The electrical resistivity of a thin copper wire and a thick copper wire are respectively \({ P }_{ 1 }\Omega \) m and \({ P }_{ 2 }\Omega \) m Then_____________.
3)
When 'n' resistors of equal resistance (R) are connected in series and in parallel respectively, then the ratio of their effective resistance is ______________
4)
Which of the following has negative temperature coefficient of resistance?
5)
The temperature co-efficient of resistance for alloys is _____________.

12th Standard Physics English Medium - Current Electricity 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?
2)
A wire of resistance 2 ohms per meter is bent to form a circle of radius 1m. The equivalent resistance between its two diametrically opposite points, A and B as shown in the figure is
3)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
4)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
5)
What is the value of resistance of the following resistor?

12th Standard Physics English Medium - Electrostatics 5 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
How do we determine the electric field due to a continuous charge distribution? Explain.
2)
Explain in detail the Electrostatic Potential difference between the charges.
3)
It requires 50 μJ of work to carry a 2C charge from point R to S. What is the potential difference between these points?
4)
Devise an arrangement of three point charges separated by finite distance that has zero electric potential energy.
5)
An electron is released from the bottom plate (E = 10⁴ Nc^-1) Find the velocity of the electron when it reaches plate B. (e/m = 1.76 x 10¹¹ Ckg^-1).

12th Standard Physics English Medium - Electrostatics 5 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Consider a point charge +q placed at the origin and another point charge -2q placed at a distance of 9 m from the charge +q. Determine the point between the two charges at which electric potential is zero.
2)
Discuss the basic properties of electric charges.
3)
Explain in detail Coulomb’s law and its various aspects.
4)
Define ‘Electric field’ and discuss its various aspects.
5)
Calculate the electric field due to a dipole on its axial line and equatorial plane.

12th Standard Physics English Medium - Electrostatics 3 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Deduce an expression for the electric field due to the system of point charges.
2)
What happens when and electric dipole is held in a non-uniform electric field?
3)
What is principle used in Microwave oven? Explain.
4)
Define potential difference and derive.

12th Standard Physics English Medium - Electrostatics 3 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Consider two point charges q₁ and q₂ at rest as shown in the figure.

They are separated by a distance of 1m. Calculate the force experienced by the two charges for the following cases:
(a) q₁ = +2μC and q₂ = +3μC
(b) q₁ = +2μC and q₂ = -3μC
(c) q₁= +2μC and q₂ = -3μC kept in water (ε_r = 80)
2)
Two small-sized identical equally charged spheres, each having mass 1 g are hanging in equilibrium as shown in the figure. The length of each string is 10 cm and the angle θ is 30° with the vertical. Calculate the magnitude of the charge in each sphere. (Take g = 10 ms⁻²)
3)
Calculate the electrostatic force and gravitational force between the proton and the electron in a hydrogen atom. They are separated by a distance of 5.3 x 10^–11 m. The magnitude of charges on the electron and proton are 1.6 x 10^–19 C. Mass of the electron is m_e = 9.1 x 10^–31 kg and mass of proton is m_p = 1.6 x 10^–27 kg.
4)
Consider four equal charges q₁, q₂, q₃ and q₄ = q = +1 μC located at four different points on a circle of radius 1m, as shown in the figure. Calculate the total force acting on the charge q₁ due to all the other charges.
5)
Calculate the electric field at points P, Q for the following two cases, as shown in the figure.
(a) A positive point charge +1 μC is placed at the origin.
(b) A negative point charge -2 μC is placed at the origin.

12th Standard Physics English Medium - Electrostatics 2 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Give a comparison of electrical and gravitional forces?
2)
What are Non-polar molecules? State examples.
3)
When does a dielectric said to be polarized?
4)
What are Polar molecules? Give examples.
5)
What are induced dipoles.

12th Standard Physics English Medium - Electrostatics 2 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Sep 01, 2022 - View & Read

1)
Calculate the number of electrons in one coulomb of negative charge.
2)
Consider the charge configuration as shown in the figure. Calculate the electric field at point A. If an electron is placed at points A, what is the acceleration experienced by this electron? (mass of the electron = 9.1 x 10^-31 kg and charge of electron = −1.6 x 10^-19C)
3)
A block of mass m carrying a positive charge q is placed on an insulated frictionless inclined plane as shown in the figure. A uniform electric field E is applied parallel to the inclined surface such that the block is at rest. Calculate the magnitude of the electric field E.
4)
The following pictures depict electric field lines for various charge configurations.

(i) In figure (a) identify the signs of two charges and find the ratio \(\left| \frac { { q }_{ 1 } }{ { q }_{ 2 } } \right| \)
(ii) In figure (b), calculate the ratio of two positive charges and identify the strength of the electric field at three points A, B, and C
(iii) Figure (c) represents the electric field lines for three charges. If q₂ = -20 nC, then calculate the values of q₁ and q₃.
5)
Calculate the electric dipole moment for the following charge configurations.

12th Standard Physics English Medium Electrostatics 1 Mark Creative Question Paper and Answer Key 2022 - 2023 - by Study Materials - Aug 23, 2022 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
Which charge configuration produces a uniform electric field?
3)
What is the ratio of the charges \(\left| \frac { { q }_{ 1 } }{ { q }_{ 2 } } \right| \) for the following electric field line pattern?
4)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
5)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.

12th Standard Physics English Medium Electrostatics 1 Mark Book Back Question Paper and Answer Key 2022 - 2023 - by Study Materials - Aug 23, 2022 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
Which charge configuration produces a uniform electric field?
3)
What is the ratio of the charges \(\left| \frac { { q }_{ 1 } }{ { q }_{ 2 } } \right| \) for the following electric field line pattern?
4)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
5)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.

12th Standard English Medium Physics Reduced syllabus Annual Exam Model Question Paper with Answer key - 2021 - by Question Bank Software - Feb 27, 2021 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
3)
The relative permittivity of water is _______.
4)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
5)
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.

12th Standard English Medium Physics Reduced syllabus Annual Exam Model Question Paper - 2021 - by Question Bank Software - Feb 27, 2021 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
Rank the electrostatic potential energies for the given system of charges in increasing order
3)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
4)
The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?
5)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.

12th Standard English Medium Physics Reduced syllabus Public Exam Model Question Paper with Answer key - 2021 - by Question Bank Software - Feb 27, 2021 - View & Read

1)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
2)
Rank the electrostatic potential energies for the given system of charges in increasing order
3)
Two metallic spheres of radii 1 cm and 3 cm are given charges of -1 \(\times\) 10^-2 C and 5 \(\times\) 10^-2 C respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is
4)
There is a current of 1.0 A in the circuit shown below. What is the resistance of P ?
5)
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of ______.

12th Standard English Medium Physics Reduced syllabus Public Exam Model Question Paper - 2021 - by Question Bank Software - Feb 27, 2021 - View & Read

1)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
2)
Two metallic spheres of radii 1 cm and 3 cm are given charges of -1 \(\times\) 10^-2 C and 5 \(\times\) 10^-2 C respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is
3)
_______ and Coulomb's law form fundamental principles of electrostatics
4)
The electric potential V as a function of distance x (metres) is given by V = ( 5x² + 10x -9) volt. The value of electric field at a point x = 1m is __________
5)
At Infinity (i.e r = ∞), the electrostatic potential (V) is

12th Standard English Medium Physics Reduced syllabus Creative Five mark Question with Answerkey - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
2)
A wire of resistance 2 ohms per meter is bent to form a circle of radius 1m. The equivalent resistance between its two diametrically opposite points, A and B as shown in the figure is
3)
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of ______.
4)
A particle having mass m and charge q accelerated through a potential difference V. Find the force experienced when it is kept under perpendicular magnetic field \(\vec { B } \).
5)
The BH curve for a ferromagnetic material is shown in the figure. The material is placed inside a long solenoid which contains 1000 turns/cm. The current that should be passed in the solenoid to demagnetize the ferromagnet completely is _____.

12th Standard English Medium Physics Reduced syllabus Creative Three mark Question with Answerkey - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
Define potential difference and derive.
2)
Derive an expression for electric flus in a non uniform electric field and an arbitrarily shaped area.
3)
What is dielectrics or insulators.
4)
(a) Distinguish between electric cells and batteries.
(b) Explain its function.
5)
Find the expression for the equivalent emf & internal resistance of the series combination of cells.

12th Standard English Medium Physics Reduced syllabus Creative two mark Question with Answerkey - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
When does a dielectric said to be polarized?
2)
What is the electric flux through a cube of side 1 cm which encloses on electric dipole?
3)
What orientation of an electric dipole in a uniform electric field corresponds to its
(i) stable and
(ii) unstable equilibrium? Depict the orientations.
4)
Two isolated metal spheres A & B have radii R & 2R respectively and same charge q. Find which of the two spheres have greater energy density just outside the surface of the sphere.
5)
The electric field due to a point charge depends on the distance r as parallely indicate how each of the following quantities depends on r?
a) Intensity of light from a point source.
b) Electrical potential due to a point charge.
c) Electrical potential at a distance r from to centre of a charged metallic sphere .Given : r < radius of the sphere.

12th Standard English Medium Physics Reduced syllabus Creative one mark Question with Answerkey - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
The torque experienced by a rectangular current loop placed perpendicular to a uniform magnetic field is
2)
Lenz's law is in accordance with the law of ________________.
3)
The efficiency of an ideal transformer is ____________.
4)
The average power consumed per cycle is ______________.
5)
An object is placed at 20 cm from a convex mirror of focal length 10 cm. The image formed by the mirror is _____________.

12th Standard English Medium Physics Reduced syllabus Five mark important Questions with Answer key - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
A parallel plate capacitor has square plates of side 5 cm and separated by a distance of 1 mm.
(a) Calculate the capacitance of this capacitor.
(b) If a 10 V battery is connected to the capacitor, what is the charge stored in any one of the plates? (The value of ε_o = 8.85 x 10^-12 Nm² C^-2)
2)
Dielectric strength of air is 3 x 10⁶ V m^-1. Suppose the radius of a hollow sphere in the Van de Graff generator is R = 0.5 m, calculate the maximum potential difference created by this Van de Graaff generator.
3)
Five identical charges Q are placed equidistant on a semicircle as shown in the figure. Another point charge q is kept at the center of the circle of radius R. Calculate the electrostatic force experienced by the charge q.
4)
The electrostatic potential is given as a function of x in figure (i) and (ii). (a) Calculate the corresponding electric fields in regions A, B, C and D for the Figure (i). (b) Plot the electric field as a function of x for the figure (ii).
5)
A battery of voltage V is connected to 30 W bulb and 60 W bulb as shown in the figure.
(a) Identify brightest bulb
(b) which bulb has greater resistance?
(c) Suppose the two bulbs are connected in series, which bulb will glow brighter?

12th Standard English Medium Physics Reduced syllabus Five mark important Questions - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
A water molecule has an electric dipole moment of 6.3 x 10^-30 Cm. A sample contains 10²² water molecules, with all the dipole moments aligned parallel to the external electric field of magnitude 3 x 10⁵ NC^-1. How much work is required to rotate all the water molecules from θ = 0° to 90°?
2)
A small ball of conducting material having a charge +q and mass m is thrown upward at an angle θ to horizontal surface with an initial speed v_o as shown in the figure. There exists an uniform electric field E downward along with the gravitational field g. Calculate the range, maximum height and time of flight in the motion of this charged ball. Neglect the effect of air and treat the ball as a point mass.
3)
Suppose a charge +q on Earth’s surface and another +q charge is placed on the surface of the Moon.
(a) Calculate the value of q required to balance the gravitational attraction between Earth and Moon.
(b) Suppose the distance between the Moon and Earth is halved, would the charge q change?
(Take m_E = 5.9 x 10²⁴ kg, m_M = 7.9 x 10²² kg)
4)
A point charge of +10 μC is placed at a distance of 20 cm from another identical point charge of +10 μC. A point charge of -2 μC is moved from point a to b as shown in the figure. Calculate the change in potential energy of the system? Interpret your result.
5)
For the given capacitor configuration
(a) Find the charges on each capacitor
(b) potential difference across them
(c) energy stored in each capacitor

12th Standard English Medium Physics Reduced syllabus Three mark important Questions with Answer key - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
Calculate the electrostatic force and gravitational force between the proton and the electron in a hydrogen atom. They are separated by a distance of 5.3 x 10^–11 m. The magnitude of charges on the electron and proton are 1.6 x 10^–19 C. Mass of the electron is m_e = 9.1 x 10^–31 kg and mass of proton is m_p = 1.6 x 10^–27 kg.
2)
Consider the charge configuration as shown in the figure. Calculate the electric field at point A. If an electron is placed at points A, what is the acceleration experienced by this electron? (mass of the electron = 9.1 x 10^-31 kg and charge of electron = −1.6 x 10^-19C)
3)
A sample of HCl gas is placed in a uniform electric field of magnitude 3 x 10⁴ NC^-1. The dipole moment of each HCl molecule is 3.4 x 10^-30 Cm. Calculate the maximum torque experienced by each HCl molecule.
4)
Obtain the expression for energy stored in the parallel plate capacitor.
5)
Explain in detail how charges are distributed in a conductor, and the principle behind the lightning conductor.

12th Standard English Medium Physics Reduced syllabus Three mark important Questions - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
Calculate the number of electrons in one coulomb of negative charge.
2)
Calculate the electrostatic force and gravitational force between the proton and the electron in a hydrogen atom. They are separated by a distance of 5.3 x 10^–11 m. The magnitude of charges on the electron and proton are 1.6 x 10^–19 C. Mass of the electron is m_e = 9.1 x 10^–31 kg and mass of proton is m_p = 1.6 x 10^–27 kg.
3)
The following pictures depict electric field lines for various charge configurations.

(i) In figure (a) identify the signs of two charges and find the ratio \(\left| \frac { { q }_{ 1 } }{ { q }_{ 2 } } \right| \)
(ii) In figure (b), calculate the ratio of two positive charges and identify the strength of the electric field at three points A, B, and C
(iii) Figure (c) represents the electric field lines for three charges. If q₂ = -20 nC, then calculate the values of q₁ and q₃.
4)
Define ‘Electric field’ and discuss its various aspects.
5)
Obtain an expression for potential energy due to a collection of three point charges which are separated by finite distances.

12th Standard English Medium Physics Reduced syllabus Two mark important Questions with Answer key - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
Define ‘electrostatic potential energy’.
2)
What are Non-polar molecules? State examples.
3)
What is meant by dielectric breakdown?
4)
What is the electric flux through a cube of side 1 cm which encloses on electric dipole?
5)
A particle of mass m and charge (-q) enters the region between the two charged plates initrally moving along X-axis with speed Vx as shown in figure. The length of plate is L and an uniform electric field E is maintained between the plates. S.T. vertical deflection of the particle at the far edge of the plate is \(\frac { q{ EL }^{ 2 } }{ 2m{ V }_{ x }^{ 2 } } \).

12th Standard English Medium Physics Reduced syllabus Two mark important Questions - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
What is meant by quantisation of charges?
2)
Define ‘electric field’
3)
(i) Two insulated charged copper spheres A & B of identical size have charges qn and -3q_A respectively. When they are brought in contact with each other and then separated. What are the new charges on them?
(ii) When third sphere of some size but uncharged is brought in contact with first and then second and finally removed? What are the new charges.
4)
A charge Q μC is placed at the centre of a cube what would be the
(i) flux through one face?
(ii) flux passing through two opposite faces of the cube?
Electric flux through whole cube \(\frac { Q }{ { \varepsilon }_{ 0 } } \)
5)
Represent the variation of electric field due to point charge Q with
a) magnitude of charge Q
b) r and
c) \(\frac{1}{r^2}\) where r is the distance of the observation point from the charge graphically.

12th Standard English Medium Physics Reduced syllabus One mark important Questions with Answer key - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
2)
The value of constant 'K' in coulomb law is _____________.
3)
Two charges are kept at a distance in air what should be the relative permittivity of the medium in which the two charges should be kept at the same distance so that they experience half of the force which they experienced in air?
4)
In a parallel plate capacitor of capacitance C, a metal sheet is inserted between the plates, parallel to them. The thickness of the sheet is half of the separation between the plates. The capacitance now becomes
5)
During charging a capacitor variation of potential V of the capacitor with time t as shown a

12th Standard English Medium Physics Reduced syllabus One mark important Questions - 2021(Public Exam ) - by Question Bank Software - Feb 27, 2021 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
3)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.
4)
Rank the electrostatic potential energies for the given system of charges in increasing order
5)
If voltage applied on a capacitor is increased from V to 2V, choose the correct conclusion.

12th Standard Physics English Medium Recent developments in Physics Reduced Syllabus Important Questions With Answer Key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
The particle size of ZnO material is 30 nm. Based on the dimension it is classified as _____.
2)
The blue print for making ultra durable synthetic material is mimicked from _____.
3)
The alloys used for muscle wires in Robots are _____.
4)
The technology used for stopping the brain from processing pain is _____.
5)
The particle which gives mass to protons and neutrons are _____.

12th Standard Physics English Medium Recent developments in Physics Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
The particle size of ZnO material is 30 nm. Based on the dimension it is classified as _____.
2)
The blue print for making ultra durable synthetic material is mimicked from _____.
3)
The materials used in Robotics are _____.
4)
The alloys used for muscle wires in Robots are _____.
5)
The technology used for stopping the brain from processing pain is _____.

12th Standard Physics English Medium Electronics and Communication Systems Reduced Syllabus Important Questions With Answer Key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
If a small amount of antimony (Sb) is added to germanium crystal,______.
2)
The output transducer of the communication system converts the radio signal into ________.
3)
The forbidden energy band gap in semi conductor, conductor and insulator are E₁, E₂ and E₃ respectively. The relation among them is _______________.
4)
The radiation of electrical energy is practicable only above _________
5)
Microphone converts __________ energy into ________ energy.

12th Standard Physics English Medium Electronics and Communication Systems Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
The output transducer of the communication system converts the radio signal into ________.
2)
Which of the following is not the advantage of PN junction diode over tube value?
3)
In an N-P-N transistor circuit, the emitter, collector, and base current are respectively I_E, I_C, and l_B. The relation between them is _____________.
4)
From the follwoing semi-conductor devices _________ operates in forward bias only.
5)
To obtain a p-type germanium semiconductor, it must be doped with _____________.

12th Standard Physics English Medium Atomic and nuclear Physics Reduced Syllabus Important Questions With Answer Key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
In a hydrogen atom, the electron revolving in the fourth orbit, has angular momentum equal to _____.
2)
The electric potential of an electron is given by \(V={ V }_{ 0 } \ In\left( \frac { r }{ { r }_{ 0 } } \right) \), where r₀ is a constant. If Bohr atom model is valid, then variation of radius of n^th orbit r_n with the principal quantum number n is _____.
3)
The fig. represents the observed intensity of X-rays emitted by an X-ray tube as a function of wavelength. The sharp peaks A and B denote ____________.
4)
A beam of electron posses undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off and the same magnetic field is maintained, the electrons move ______________.
5)
The energy of a photon of characteristic X-ray from a Coolidge tubes comes from ___________.

12th Standard Physics English Medium Atomic and nuclear Physics Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
Suppose an alpha particle accelerated by a potential of V volt is allowed to collide with a nucleus of atomic number Z, then the distance of closest approach of alpha particle to the nucleus is _____.
2)
The electric potential of an electron is given by \(V={ V }_{ 0 } \ In\left( \frac { r }{ { r }_{ 0 } } \right) \), where r₀ is a constant. If Bohr atom model is valid, then variation of radius of n^th orbit r_n with the principal quantum number n is _____.
3)
An oil drop carrying a charge q has a mass of m kg. It is falling freely in the air with terminal speed v. The electric field required to make the drop move upwards with the same speed is ______________.
4)
When hydrogen atom is in its first excited level, its radius is __________ of the Bohr radius.
5)
J.J. Thomson's experiment demonstrated that ______________.

12th Standard Physics English Medium Dual Nature of Radiation and Matter Reduced Syllabus Important Questions With Answer Key 20211 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
The wavelength λ_eof an electron and λ_p of a photon of same energy E are related by _____.
2)
If a light of wavelength 330 nm is incident on a metal with work function 3.55 eV, the electrons are emitted. Then the wavelength of the wave associated with the emitted electron is _____.(Take h = 6.6 x 10^–34 Js)
3)
A photoelectric surface is illuminated successively by monochromatic light of wavelength λ and λ /2. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the material is _____.
4)
The threshold wavelength for a metal surface whose photoelectric work function is 3.313 eV is _____.
5)
Emission of electrons by the absorption of heat energy is called ______ emission.

12th Standard Physics English Medium Dual Nature of Radiation and Matter Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
The wavelength λ_eof an electron and λ_p of a photon of same energy E are related by _____.
2)
In an electron microscope, the electrons are accelerated by a voltage of 14 kV. If the voltage is changed to 224 kV, then the de Broglie wavelength associated with the electrons would _____.
3)
The wave associated with a moving particle of mass 3 x 10^–6 g has the same wavelength as an electron moving with a velocity 6 x 10⁶ ms^-1. The velocity of the particle is _____.
4)
Photons of wavelength λ are incident on a metal. The most energetic electrons ejected from the metal are bent into a circular arc of radius R by a perpendicular magnetic field having magnitude B. The work function of the metal is _____.
5)
The work functions for metals A, B and C are 1.92 eV, 2.0 eV and 5.0 eV respectively. The metal/metals which will emit photoelectrons for a radiation of wavelength 4100 Å is/are _____.

12th Standard Physics English Medium Wave Optics Reduced Syllabus Important Questions With Answer Key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
A plane glass is placed over a various coloured letters (violet, green, yellow, red) The letter which appears to be raised more is _____.
2)
In a Young’s double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to, _____.
3)
Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are _____.
4)
When light is incident on a soap film of thickness 5 x 10^–5 cm, the wavelength of light reflected maximum in the visible region is 5320 Å. Refractive index of the film will be, _____.
5)
First diffraction minimum due to a single slit of width 1.0 x 10^–5 cm is at 30^o. Then wavelength of light used is,_____.

12th Standard Physics English Medium Wave Optics Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
A plane glass is placed over a various coloured letters (violet, green, yellow, red) The letter which appears to be raised more is _____.
2)
In a Young’s double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to, _____.
3)
Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are _____.
4)
When light is incident on a soap film of thickness 5 x 10^–5 cm, the wavelength of light reflected maximum in the visible region is 5320 Å. Refractive index of the film will be, _____.
5)
First diffraction minimum due to a single slit of width 1.0 x 10^–5 cm is at 30^o. Then wavelength of light used is,_____.

12th Standard Physics English Medium Ray Optics Reduced Syllabus Important Questions With Answer Key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
An object is placed in front of a convex mirror of focal length off and the maximum and minimum distance of an object from the mirror such that the image formed is real and magnified.
2)
For light incident from air on a slab of refractive index 2, the maximum possible angle of refraction is, ______.
3)
Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm approximately. The maximum distance at which these dots can be resolved by the eye is_____. [take wavelength of light, λ = 500 nm]
4)
A light bulb is placed between two mirrors (plane) inclined at an angle of 60°. Number of images formed are ________________.
5)
A man of length h requires a mirror of length at least equal to, to see his own complete image is _______________.

12th Standard Physics English Medium Ray Optics Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
The speed of light in an isotropic medium depends on, ______.
2)
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as plane sheet of glass. This implies that the liquid must have refractive index, ______.
3)
A ray of light travelling in a transparent medium of refractive index n falls, on a surface separating the medium from air at an angle of incidents of 45^o . The ray can undergo total internal reflection for the following n, ______.
4)
The light reflected by plane mirror may form a real images ____________.
5)
Ray optics is valid, when characteristic dimensions are ______________.

12th Standard Physics English Medium Electromagnetic Waves Reduced Syllabus Important Questions With Answer Key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
If the magnetic monopole exists, then which of the Maxwell’s equation to be modified?
2)
Who produced the electromagnetic waves first?
3)
The existence of E.M. waves was confirmed experimentally by __________________.
4)
Electromagnetic waves are discovered by _______________.
5)
Cellular phones use radio frequencies in ______________.

12th Standard Physics English Medium Electromagnetic Waves Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
If the magnetic monopole exists, then which of the Maxwell’s equation to be modified?
2)
The phase and orientation of the magnetic vector associated with electromagnetic oscillations differ respectively from those of the corresponding electric vectors by _______________.
3)
Which one of the following is not an electromagnetic waves?
4)
Calcium or Barium salts in bunsen flame, CO₂, N₂ molecule, NH₃ gas in a discharge tube gives_______.
5)
__________discovered electromagnetic induction.

12th Standard Physics English Medium Electromagnetic Induction and Alternating Current Reduced Syllabus Important Questions With Answer Key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
2)
A circular coil with a cross-sectional area of 4 cm² has 10 turns. It is placed at the centre of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm². The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?
3)
In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is
4)
In a series resonant RLC circuit, the voltage across 100 Ω resistor is 40 V. The resonant frequency ω is 250 rad/s. If the value of C is 4 µF, then the voltage across L is
5)
In an oscillating LC circuit, the maximum charge on the capacitor is Q. The charge on the capacitor when the energy is stored equally between the electric and magnetic fields is

12th Standard Physics English Medium Electromagnetic Induction and Alternating Current Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
An electron moves on a straight line path XY as shown in the figure. The coil abcd is adjacent to the path of the electron. What will be the direction of current, if any, induced in the coil?
2)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
3)
In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is
4)
An emf of 12V is induced when the current in the coil changes at the rate of 40 A S^-1. The coefficient of self induction of the coil is __________________.
5)
Transformer works on _____________.

12th Standard Physics English Medium Magnetism and Magnetic Effects of Electric Current Reduced Syllabus Important Questions with Answer key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
A particle having mass m and charge q accelerated through a potential difference V. Find the force experienced when it is kept under perpendicular magnetic field \(\vec { B } \).
2)
Three wires of equal lengths are bent in the form of loops. One of the loops is circle, another is a semi-circle and the third one is a square. They are placed in a uniform magnetic field and same electric current is passed through them. Which of the following loop configuration will experience greater torque?
3)
A wire of length l carrying a current I along the Y direction is kept in a magnetic field is given by \(\vec { B } =\frac { \beta }{ \sqrt { 3 } } =(\hat { i } +\hat { j } +\hat { k } )T.\) The magnitude of Lorentz force acting on the wire is _____.
4)
The direction of the magnetic force on a positive charge moving in a magnetic field is given by ________________.
5)
Consider the motion of a charged particle in a uniform magnetic field directed into the paper. If velocity v of the particle is in the plane of the paper, the charged particle will describe a _____________.

12th Standard Physics English Medium Magnetism and Magnetic Effects of Electric Current Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
The magnetic field at the centre O of the following current loop is
2)
An electron moves in a straight line inside a charged parallel plate capacitor of uniform charge density σ. The time taken by the electron to cross the parallel plate capacitor undeflected when the plates of the capacitor are kept under constant magnetic field of induction \((\vec{B})\) is
3)
Three wires of equal lengths are bent in the form of loops. One of the loops is circle, another is a semi-circle and the third one is a square. They are placed in a uniform magnetic field and same electric current is passed through them. Which of the following loop configuration will experience greater torque?
4)
A wire of length l carrying a current I along the Y direction is kept in a magnetic field is given by \(\vec { B } =\frac { \beta }{ \sqrt { 3 } } =(\hat { i } +\hat { j } +\hat { k } )T.\) The magnitude of Lorentz force acting on the wire is _____.
5)
The BH curve for a ferromagnetic material is shown in the figure. The material is placed inside a long solenoid which contains 1000 turns/cm. The current that should be passed in the solenoid to demagnetize the ferromagnet completely is _____.

12th Standard Physics English Medium Current Electricity Reduced Syllabus Important Questions with Answer key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
A wire connected to a power supply of 230 V has power dissipation P₁. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is P₂. The ratio \(\frac{P_2}{P_1}\) is ______.
2)
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.
3)
When 'n' resistors of equal resistance (R) are connected in series and in parallel respectively, then the ratio of their effective resistance is ______________
4)
A potential difference is applied an the ends of a metallic wire. If the potential difference is doubled, the drift velocity ________________.
5)
A bird sitting on an insulated wire carrying a current feels quite safe because ____________.

12th Standard Physics English Medium Current Electricity Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
There is a current of 1.0 A in the circuit shown below. What is the resistance of P ?
2)
When 'n' resistors of equal resistance (R) are connected in series and in parallel respectively, then the ratio of their effective resistance is ______________
3)
An unknown resistance is connected in parallel with a 15\(\Omega \) resistance and a 12V battery. What is the value of the unknown resistance if the current in the circuit is 2A?
4)
Kirchoff's I law i.e, \(\Sigma i=0\) at a junction, deals with the conservation of ______________.
5)
Resistance increases with increases in temperature for _________________.

12th Standard Physics English Medium Electrostatics Reduced Syllabus Important Questions with Answer key 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
The total electric flux for the following closed surface which is kept inside water
3)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
4)
_______ and Coulomb's law form fundamental principles of electrostatics

12th Standard Physics English Medium Electrostatics Reduced Syllabus Important Questions 2021 - by Question Bank Software - Jan 27, 2021 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
The total electric flux for the following closed surface which is kept inside water
3)
_______ and Coulomb's law form fundamental principles of electrostatics
4)
A force of 40 N is acting between two charges in air if the space between then is filled with glass ε_r = 8. Then the force between then is __________
5)
The expression for electric field in vector form is

12th Standard Physics English Medium Reduced Syllabus Model Question paper with answer key - 2021 Part - 2 - by Question Bank Software - Jan 25, 2021 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
The total electric flux for the following closed surface which is kept inside water
3)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
4)
The figure shows tow parallel equipotential surface A and B kept at a small distance 'r' a part from each other. A point change of Q coulomb is taken from the surface A to B. The amount of net work done will be
5)
During charging a capacitor variation of potential V of the capacitor with time t as shown a

12th Standard Physics English Medium Reduced Syllabus Model Question paper with answer key - 2021 Part - 1 - by Question Bank Software - Jan 25, 2021 - View & Read

1)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
2)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
3)
Two identical coils, each with N turns and radius R are placed coaxially at a distance R as shown in the figure. If I is the current passing through the loops in the same direction, then the magnetic field at a point P at a distance of R/2 from the centre of each coil is _____.
4)
A thin semi-circular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure.

The potential difference developed across the ring when its speed v, is
5)
An inductor 20 mH, a capacitor 50 μF and a resistor 40Ω are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is

12th Standard Physics English Medium Reduced Syllabus Model Question paper - 2021 Part - 2 - by Question Bank Software - Jan 25, 2021 - View & Read

1)
In tuning radio we use,
2)
Two short bar magnets have magnetic moments 1.20 Am² and 1.00 Am² respectively. They are kept on a horizontal table parallel to each other with their north poles pointing towards south. They have a common magnetic equator and are separated by a distance of 20.0 cm. The value of the resultant horizontal magnetic induction at the mid-point O of the line joining their centres is (Horizontal components of Earth’s magnetic induction is 3.6 × 10^–5 Wb m^–2 )
3)
The electrical series circuit in digital form is
4)
A current gain for, a transistor working as CB amplifier is 0.90. If emitter current is 10 mA, then base current is ________________.
5)
Digital circuits can be made to be respective use of ______________.

12th Standard Physics English Medium Reduced Syllabus Model Question paper - 2021 Part - 1 - by Question Bank Software - Jan 25, 2021 - View & Read

1)
An uncharged metal sphere is placed between two equal and oppositely charged metal plates. The nature of lines of force will be ______________
2)
In three-phase AC generator the three coils are fastened rigidly together and are displaced from each other by an angle _______________.
3)
In an a.c. circuit with an inductor ______________.
4)
In an LCR series a.c, circuit, the phase difference between current and voltage is 60°. If the net reactance of the circuit is 17.32Ω, the value of the resistance is ______________.
5)
Which of the following is used to study crystal structure?

12th Standard Physics English Medium Reduced Syllabus Important Questions with Answer key - 2021 Part - 2 - by Question Bank Software - Jan 25, 2021 - View & Read

1)
What physical quantities may X and Y represent? [Y represents the first mentioned quantity].
2)
Which one of the following pair of particles move with same velocity along the same circular path in a uniform magnetic field?
3)
This works on the principle of Tangent Law ____________________.
4)
An α-particle enters a magnetic field of 1T with a velocity 10⁶ m/s in a direction perpendicular to the field. The force on α-particle is _____________________.
5)
Which of the following electromagnetic radiations is used for viewing objects through fog

12th Standard Physics English Medium Reduced Syllabus Important Questions with Answer key - 2021 Part - 1 - by Question Bank Software - Jan 25, 2021 - View & Read

1)
By using law of conservation of electric charge balance the following equations:
₉₂U²³⁸ ⇾₉₀Th²³⁴+________.
2)
There is a current of 1.0 A in the circuit shown below. What is the resistance of P ?
3)
An unknown resistance is connected in parallel with a 15\(\Omega \) resistance and a 12V battery. What is the value of the unknown resistance if the current in the circuit is 2A?
4)
The instantaneous values of alternating current and voltage in a circuit are \(i=\frac { 1 }{ \sqrt { 2 } } \sin\left( 100\pi t \right) \) A and v \(=\frac { 1 }{ \sqrt { 2 } } \sin\left( 100\pi t+\frac { \pi }{ 3 } \right) V.\)The average power in watts consumed in the circuit is
5)
Lenz's law is in accordance with the law of ________________.

12th Standard Physics English Medium Reduced Syllabus Important Questions - 2021 Part - 2 - by Question Bank Software - Jan 25, 2021 - View & Read

1)
The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.
2)
The emf of a battery is 3 volts and internal resistance 0.125 \(\Omega \) . The difference of potential at the terminal of battery when connected across an external resistance of 1 \(\Omega \) is ______________.
3)
Peltier effect is the converse of _____________.
4)
Kirchoff's II law isa consequence of conservation of________
5)
Which one of the following is correct. According to Biot-Savart law, the magnetic induction is directly proportional to _________________.

12th Standard Physics English Medium Reduced Syllabus Important Questions - 2021 Part - 1 - by Question Bank Software - Jan 25, 2021 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
3)
The total electric flux for the following closed surface which is kept inside water
4)
The electric field created by a _________ is basically a non-uniform electric field.
5)
The unit for electric susceptibility is

12th Standard Physics Recent Developments in Physics English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
Which one of the following is the natural nanomaterial.
2)
The method of making nanomaterial by assembling the atoms is called _____.
3)
The materials used in Robotics are _____.
4)
The technology used for stopping the brain from processing pain is _____.
5)
The gravitational waves were theoretically proposed by _____.

12st Standard Physics Recent Developments in Physics English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The particle size of ZnO material is 30 nm. Based on the dimension it is classified as _____.
2)
The blue print for making ultra durable synthetic material is mimicked from _____.
3)
The alloys used for muscle wires in Robots are _____.
4)
The particle which gives mass to protons and neutrons are _____.
5)
__________ Scanning Electron Micrograph (SEM) showing the nano structures on the surface of a leaf from a lotus plant

12th Standard Physics Communication Systems English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The signal is aff ected by noise in a communication system _____________.
2)
The internationally accepted frequency deviation for the purpose of FM broadcasts ____________.
3)
The loss of strengh of a signal while propagating through a medium is known as_________.
4)
Modulation is the process of superposing _______________.
5)
Large band width for higher data is achieved by using ________________.

12th Standard Physics Communication Systems English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The output transducer of the communication system converts the radio signal into ________.
2)
The variation of frequency of carrier wave with respect to the amplitude of the modulating signal is called ______.
3)
The frequency range of 3 MHz to 30 MHz is used for ______.
4)
All medium wave signals received during day time use __________ wave propagation.
5)
The radio waves after refraction from different part of ionosphere on reaching the earth are called as _______________.

12th Standard Physics Semiconductor Electronics English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
If a small amount of antimony (Sb) is added to germanium crystal,______.
2)
When a transistor is fully switched on, it is said to be _________________.
3)
The electrical series circuit in digital form is
4)
By adding _________ impurity in intrinsic semi conductor, p type semiconductor is made. Charge of these p type semiconductor is ____________
5)
The behaviour of Ge as semi-conductor is due to width of ___________.

12th Standard Physics Semiconductor Electronics English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The barrier potential of a silicon diode is approximately, ______.
2)
The zener diode is primarily used as ______.
3)
The light emitted in an LED is due to ______.
4)
The specific characteristic of a common emitter amplifier is _______________.
5)
If the input to the NOT gate is A = 1011, its output is ______.

12th Standard Physics Atomic and Nuclear physics English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
In a hydrogen atom, the electron revolving in the fourth orbit, has angular momentum equal to _____.
2)
The electric potential of an electron is given by \(V={ V }_{ 0 } \ In\left( \frac { r }{ { r }_{ 0 } } \right) \), where r₀ is a constant. If Bohr atom model is valid, then variation of radius of n^th orbit r_n with the principal quantum number n is _____.
3)
The nucleus is approximately spherical in shape. Then the surface area of nucleus having mass number A varies as _____.
4)
The half-life period of a radioactive element A is same as the mean life time of another radioactive element B. Initially both have the same number of atoms. Then _____.
5)
The circumference of an electron's orbit of radius r must be an integral multiple of de Broglie wavelength that is ________________.

12th Standard Physics Atomic and Nuclear physics English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
Suppose an alpha particle accelerated by a potential of V volt is allowed to collide with a nucleus of atomic number Z, then the distance of closest approach of alpha particle to the nucleus is _____.
2)
The ratio of the wavelengths radiation emitted for the transition from n = 2 to n = 1 in Li⁺⁺, He⁺and H is _____.
3)
If the nuclear radius of ²⁷Al is 3.6 fermi, the approximate nuclear radius of ⁶⁴Cu, in femi is _____.
4)
A radioactive nucleus (initial mass number A and atomic number Z) emits two α-particles and 2 positons. The ratio of number of neutrons to that of proton in the final nucleus will be _____.
5)
A radiative element has N₀ number of nuclei at t = 0. The number of nuclei remaining after half of a half-life _____.(that is, at time t = \(\frac{1}{2}T_\frac{1}{2}\))

12th Standard Physics Dual Nature of Radiation and Matter English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
In an electron microscope, the electrons are accelerated by a voltage of 14 kV. If the voltage is changed to 224 kV, then the de Broglie wavelength associated with the electrons would _____.
2)
Two radiations with photon energies 0.9 eV and 3.3 eV respectively are falling on a metallic surface successively. If the work function of the metal is 0.6 eV, then the ratio of maximum speeds of emitted electrons in the two cases will be _____.
3)
If the mean wavelength of light from sun is taken as 550 nm and its mean power as 3.8 x 10²⁶W, then the number of photons emitted per second from the sun is of the order of _____.
4)
The work functions for metals A, B and C are 1.92 eV, 2.0 eV and 5.0 eV respectively. The metal/metals which will emit photoelectrons for a radiation of wavelength 4100 Å is/are _____.
5)
The work function of a metal is hv₀. Light of frequency v falls on this metal. The photoelectric effect will take place only if ___________.

12th Standard Physics Dual Nature of Radiation and Matter English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The wavelength λ_eof an electron and λ_p of a photon of same energy E are related by _____.
2)
A light source of wavelength 520 nm emits 1.04 x 10¹⁵photons per second while the second source of 460 nm produces 1.38 x 10¹⁵ photons per second. Then the ratio of power of second source to that of first source is _____.
3)
Photons of wavelength λ are incident on a metal. The most energetic electrons ejected from the metal are bent into a circular arc of radius R by a perpendicular magnetic field having magnitude B. The work function of the metal is _____.
4)
Emission of electrons by the absorption of heat energy is called ______ emission.
5)
P and E denote the linear momentum and energy of a photon. If the wavelength is decreased ____________.

12th Standard Physics Optics English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is, ______.
2)
The radius of curvature of curved surface at a thin planoconvex lens is 10 cm and the refractive index is 1.5. If the plane surface is silvered, then the focal length will be, ______.
3)
Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are _____.
4)
First diffraction minimum due to a single slit of width 1.0 x 10^–5 cm is at 30^o. Then wavelength of light used is,_____.
5)
One of the of Young’s double slits is covered with a glass plate as shown in figure. The position of central maximum will,_____.

12th Standard Physics Optics English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The speed of light in an isotropic medium depends on, ______.
2)
An object is placed in front of a convex mirror of focal length off and the maximum and minimum distance of an object from the mirror such that the image formed is real and magnified.
3)
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as plane sheet of glass. This implies that the liquid must have refractive index, ______.
4)
An air bubble in glass slab of refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness of the slab is ______.
5)
A plane glass is placed over a various coloured letters (violet, green, yellow, red) The letter which appears to be raised more is _____.

12th Standard Physics Electromagnetic Waves English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
If the amplitude of the magnetic field is 3 x 10⁻⁶ T, then amplitude of the electric field for a electromagnetic waves is _____.
2)
The electric and the magnetic fields, associated with an electromagnetic wave, propagating along negative X axis can be represented by _____.
3)
A radiation of energy E falls normally on a perfectly reflecting surface. Th e momentum transferred to the surface __________________.
4)
Which one of them is used to produce a propagating electromagnetic wave?
5)
Which of the following is NOT true for electromagnetic waves?

12th Standard Physics Electromagnetic Waves English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The dimension of \(\frac { 1 }{ { \mu }_{ 0 }{ \varepsilon }_{ 0 } } \) is _____.
2)
Which of the following electromagnetic radiations is used for viewing objects through fog
3)
If the magnetic monopole exists, then which of the Maxwell’s equation to be modified?
4)
Which of the following is an electromagnetic wave?
5)
If E = E_o sin[10⁶ x -ωt] be the electric field of a plane electromagnetic wave, the value of ω is_____.

12th Standard Physics Electromagnetic Induction and Alternating Current English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
2)
A circular coil with a cross-sectional area of 4 cm² has 10 turns. It is placed at the centre of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm². The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?
3)
In a series RL circuit, the resistance and inductive reactance are the same. Then the phase difference between the voltage and current in the circuit is
4)
An inductor 20 mH, a capacitor 50 μF and a resistor 40Ω are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is
5)
Lenz's law is in accordance with the law of ________________.

12th Standard Physics Electromagnetic Induction and Alternating Current English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
An electron moves on a straight line path XY as shown in the figure. The coil abcd is adjacent to the path of the electron. What will be the direction of current, if any, induced in the coil?
2)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
3)
In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is
4)
The instantaneous values of alternating current and voltage in a circuit are \(i=\frac { 1 }{ \sqrt { 2 } } \sin\left( 100\pi t \right) \) A and v \(=\frac { 1 }{ \sqrt { 2 } } \sin\left( 100\pi t+\frac { \pi }{ 3 } \right) V.\)The average power in watts consumed in the circuit is
5)
Electromagnetic induction is-not used in ___________________.

12th Standard Physics Magnetism and magnetic effects of electric current English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
An electron moves in a straight line inside a charged parallel plate capacitor of uniform charge density σ. The time taken by the electron to cross the parallel plate capacitor undeflected when the plates of the capacitor are kept under constant magnetic field of induction \((\vec{B})\) is
2)
A wire of length l carrying a current I along the Y direction is kept in a magnetic field is given by \(\vec { B } =\frac { \beta }{ \sqrt { 3 } } =(\hat { i } +\hat { j } +\hat { k } )T.\) The magnitude of Lorentz force acting on the wire is _____.
3)
A non-conducting charged ring carrying a charge of q, mass m and radius r is rotated about its axis with constant angular speed ω. Find the ratio of its magnetic moment with angular momentum is _____.
4)
A flat dielectric disc of radius R carries an excess charge on its surface. The surface charge density is σ. The disc rotates about an axis perpendicular to its plane passing through the center with angular velocity ω. Find the magnitude of the torque on the disc if it is placed in a uniform magnetic field whose strength is B which is directed perpendicular to the axis of rotation.
5)
In a thermocouple, the temperature of cold junction is 30°C and the neutral temperature is 310°C. The temperature of inversion is ______________________.

12th Standard Physics Magnetism and magnetic effects of electric current English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The magnetic field at the centre O of the following current loop is
2)
A particle having mass m and charge q accelerated through a potential difference V. Find the force experienced when it is kept under perpendicular magnetic field \(\vec { B } \).
3)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.
4)
A bar magnet of length l and magnetic moment p_m is bent in the form of an arc as shown in Figure. The new magnetic dipole moment will be
5)
The BH curve for a ferromagnetic material is shown in the figure. The material is placed inside a long solenoid which contains 1000 turns/cm. The current that should be passed in the solenoid to demagnetize the ferromagnet completely is _____.

12th Standard Physics Current Electricity English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
A wire of resistance 2 ohms per meter is bent to form a circle of radius 1m. The equivalent resistance between its two diametrically opposite points, A and B as shown in the figure is
2)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
3)
There is a current of 1.0 A in the circuit shown below. What is the resistance of P ?
4)
The temperature coefficient of resistance of a wire is 0.00125 per °C. At 20°C, its resistance is 1 Ω. The resistance of the wire will be 2 Ω at ______.
5)
The electrical resistivity of a thin copper wire and a thick copper wire are respectively \({ P }_{ 1 }\Omega \) m and \({ P }_{ 2 }\Omega \) m Then_____________.

12th Standard Physics Current Electricity English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?
2)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
3)
What is the value of resistance of the following resistor?
4)
A wire connected to a power supply of 230 V has power dissipation P₁. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is P₂. The ratio \(\frac{P_2}{P_1}\) is ______.
5)
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.

12th Standard Physics Electrostatics English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
What is the ratio of the charges \(\left| \frac { { q }_{ 1 } }{ { q }_{ 2 } } \right| \) for the following electric field line pattern?
2)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.
3)
The total electric flux for the following closed surface which is kept inside water
4)
Rank the electrostatic potential energies for the given system of charges in increasing order
5)
Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is

12th Standard Physics Electrostatics English Medium Free Online Test One Mark questions 2020 - 2021 - by Question Bank Software - Oct 13, 2020 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
A thin conducting spherical shell of radius R has a charge Q which is uniformly distributed on its surface. The correct plot for electrostatic potential due to this spherical shell is _____.
3)
Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is
4)
In a hydrogen atom the electron revolves around the proton in an orbit of 0.53 \(\mathring { A } \). The potential produced by the electron on the nuleus is ___________
5)
The electric field created by a _________ is basically a non-uniform electric field.

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Ten - by Question Bank Software - Oct 12, 2020 - View & Read

1)
If voltage applied on a capacitor is increased from V to 2V, choose the correct conclusion.
2)
The electric field created by a _________ is basically a non-uniform electric field.
3)
Which of the following cannot be the units of electric field intensity?
4)
A wire of resistance 2 ohms per meter is bent to form a circle of radius 1m. The equivalent resistance between its two diametrically opposite points, A and B as shown in the figure is
5)
Temperature co-effieient of resistance for metals is ______________.

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Ten - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Two points A and B are maintained at a potential of 7 V and -4 V respectively. The work done in moving 50 electrons from A to B is _______.
2)
The time taken by a conductor to reach electrostatic equilibrium is in the order of
3)
The force between like charges is _________.
4)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
5)
The equivalent resistance between A and B in the figure is

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Nine - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
2)
A parallel plate capacitor stores a charge Q at a voltage V. Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?
3)
What physical quantities may X and Y represent? [Y represents the first mentioned quantity].
4)
The electric flux is ________ if the electric field lines enter the closed surface.
5)
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Nine - by Question Bank Software - Oct 12, 2020 - View & Read

1)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
2)
Van de Graaff generator produces an electrostatic potential difference of_______ volts.
3)
When a point charge of 6mC is moved between two points in an electric field, the work done is 1.8 x 10^-5 J. The potential difference between the two points is
4)
Near a charged object A another earthed object B is placed. Charges are induced on B. If B is removed. After that the charge on A ________.

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Eight - by Question Bank Software - Oct 12, 2020 - View & Read

1)
If voltage applied on a capacitor is increased from V to 2V, choose the correct conclusion.
2)
Two charged bodies of charges +q, -3q are brought in contact and separated. The charges prossed by each body after separation.
3)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
4)
The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.
5)
The temperature coefficient of resistance is positive__________.

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Eight - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is
2)
What will happen if two conducting spheres are separately charged and then brought in contact?
3)
During charging a capacitor variation of potential V of the capacitor with time t as shown a
4)
The total dipole moment per unit volume of the dielectric is________.
5)
The repulsive force between two like charges of 1 coulomb each separated by a distance of 1 m in vacuum is equal to :

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Seven - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
2)
A non-conducting material which has no free electrons is called
3)
The electric flux through a surface will be minimum when the angle between E and A is
4)
Charge Q on a capacitor varies with voltage V as shown in graph, where Q is along X-axis and V along Y-axis. The area of triangle OAB represents
5)
A Gaussian surface in the figure is shown by dotted line. The electric field on the surface will be

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Seven - by Question Bank Software - Oct 12, 2020 - View & Read

1)
A parallel plate capacitor stores a charge Q at a voltage V. Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?
2)
The value of constant 'K' in coulomb law is _____________.
3)
Four plates each of area N and inferplate separation 'd' are placed as shown in figure. The two inner plates are connected to the point 'B' and outer to point 'A'. What is equivalent capacitance?
4)
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of ______.
5)
Which of the following has negative temperature coefficient of resistance?

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Six - by Question Bank Software - Oct 12, 2020 - View & Read

1)
A thin conducting spherical shell of radius R has a charge Q which is uniformly distributed on its surface. The correct plot for electrostatic potential due to this spherical shell is _____.
2)
Charge Q on a capacitor varies with voltage V as shown in graph, where Q is along X-axis and V along Y-axis. The area of triangle OAB represents
3)
When an electric dipole is placed in a uniform external electric field parallel to the field, it will experience_________.
4)
A wire of resistance 2 ohms per meter is bent to form a circle of radius 1m. The equivalent resistance between its two diametrically opposite points, A and B as shown in the figure is
5)
Four resistances are connected to a 5V battery of negligible internal resistance as shown what is the potential across \(2\Omega \)?

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Six - by Question Bank Software - Oct 12, 2020 - View & Read

1)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
2)
The direction of electric field at a point the equatorial line due to an electric dipole is
3)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
4)
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of ______.

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Five - by Question Bank Software - Oct 12, 2020 - View & Read

1)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
2)
An isolated metal sphere of radius 'r' is given a charge' q'. The potential energy of the sphere is ____________
3)
The expression for electric potential difference is
4)
Torque experienced by a dipole in an electric field when it is placed parallel to the field is ______.
5)
What is the current drawn out from the battery?

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Five - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Rank the electrostatic potential energies for the given system of charges in increasing order
2)
A positively charged body 'A' has been brought near a brass cylinder 'B' mounted on a glass stand as shown in the figure. The potential of 'B' will be
3)
What physical quantities may X and Y represent? [Y represents the first mentioned quantity].
4)
Electrostatics deals with the _________
5)
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.

12th Standard Physics English Medium Free Online Test One Mark Questions with Answer Key 2020 - Part Four - by Question Bank Software - Oct 12, 2020 - View & Read

1)
A thin conducting spherical shell of radius R has a charge Q which is uniformly distributed on its surface. The correct plot for electrostatic potential due to this spherical shell is _____.
2)
The given figure is a plot of lines of force due to two charges q₁ & q₂ find out the sign of charges
3)
A wire connected to a power supply of 230 V has power dissipation P₁. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is P₂. The ratio \(\frac{P_2}{P_1}\) is ______.
4)
In the case of Wheatstone's Bridge the bridge balance condition will be obtained only when____
5)
Two short bar magnets have magnetic moments 1.20 Am² and 1.00 Am² respectively. They are kept on a horizontal table parallel to each other with their north poles pointing towards south. They have a common magnetic equator and are separated by a distance of 20.0 cm. The value of the resultant horizontal magnetic induction at the mid-point O of the line joining their centres is (Horizontal components of Earth’s magnetic induction is 3.6 × 10^–5 Wb m^–2 )

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Four - by Question Bank Software - Oct 12, 2020 - View & Read

1)
If voltage applied on a capacitor is increased from V to 2V, choose the correct conclusion.
2)
A force of 40 N is acting between two charges in air if the space between then is filled with glass ε_r = 8. Then the force between then is __________
3)
Two copper spheres A and B of same size are charged to same potential. A is hollow and B is solid. Which of the two holds more charge?
4)
Which graph shows the variation of electric field E due to a hollow spherical conductor of radius R as a function of distance from the centre of the sphere?
5)
A closed system contains four charges -8.1C, 14.6C, 20.2C and -200 mC. The total charge in the system_______.

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Three - by Question Bank Software - Oct 12, 2020 - View & Read

1)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
2)
Charge per unit volume is called _____________
3)
The negative gradient of potential is
4)
A charge Q μ C is placed at the center of a cube. The flux coming out from any surface will be
5)
Surface density of charge on a sphere of radius R in terms of electric intensity E at a distance r in free space is

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Three - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.
2)
In a parallel plate capacitor of capacitance C, a metal sheet is inserted between the plates, parallel to them. The thickness of the sheet is half of the separation between the plates. The capacitance now becomes
3)
In a hollow spherical shell potential (V) changes with respect to distance (r) from centre.
\(\left[ { V }_{ inside }=\frac { Q }{ 4\pi { \varepsilon }_{ 0 }R } r\le R,\quad { V }_{ outside }=\frac { Q }{ 4\pi { \varepsilon }_{ 0 }r } r\ge R,V\alpha \frac { 1 }{ r } \right] \)
4)
Two wires of A and B with circular cross section made up of the same material with equal lengths. Suppose R_A = 3 R_B, then what is the ratio of radius of wire A to that of B?
5)
When the free electrons are moving in all possible directions, the value of the current produced is_______

12th Standard Physics English Medium Free Online Test Book Back 1 Mark Questions with Answer Key - Part Three - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Two points A and B are maintained at a potential of 7 V and -4 V respectively. The work done in moving 50 electrons from A to B is _______.
2)
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.
3)
A non-conducting charged ring carrying a charge of q, mass m and radius r is rotated about its axis with constant angular speed ω. Find the ratio of its magnetic moment with angular momentum is _____.
4)
The current i flowing in a coil varies with time as shown in the figure. The variation of induced emf with time would be
5)
Consider an oscillator which has a charged particle oscillating about its mean position with a frequency of 300 MHz. The wavelength of electromagnetic waves produced by this oscillator is _____.

12th Standard Physics English Medium Free Online Test Book Back One Mark Questions - Part Three - by Question Bank Software - Oct 12, 2020 - View & Read

1)
The total electric flux for the following closed surface which is kept inside water
2)
The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?
3)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.
4)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
5)
Consider an oscillator which has a charged particle oscillating about its mean position with a frequency of 300 MHz. The wavelength of electromagnetic waves produced by this oscillator is _____.

12th Standard Physics English Medium Free Online Test Book Back 1 Mark questions with Answer Key - Part Two - by Question Bank Software - Oct 12, 2020 - View & Read

1)
A parallel plate capacitor stores a charge Q at a voltage V. Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?
2)
Two short bar magnets have magnetic moments 1.20 Am² and 1.00 Am² respectively. They are kept on a horizontal table parallel to each other with their north poles pointing towards south. They have a common magnetic equator and are separated by a distance of 20.0 cm. The value of the resultant horizontal magnetic induction at the mid-point O of the line joining their centres is (Horizontal components of Earth’s magnetic induction is 3.6 × 10^–5 Wb m^–2 )
3)
An inductor 20 mH, a capacitor 50 μF and a resistor 40Ω are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is
4)
Which of the following is an electromagnetic wave?
5)
A ray of light strikes a glass plate at an angle 60^o. If the reflected and refracted rays are perpendicular to each other, the refractive index of the glass is, _____.

12th Standard Physics English Medium Free Online Test Book Back one Mark questions - Part Two - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is
2)
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of ______.
3)
A flat dielectric disc of radius R carries an excess charge on its surface. The surface charge density is σ. The disc rotates about an axis perpendicular to its plane passing through the center with angular velocity ω. Find the magnitude of the torque on the disc if it is placed in a uniform magnetic field whose strength is B which is directed perpendicular to the axis of rotation.
4)
In an oscillating LC circuit, the maximum charge on the capacitor is Q. The charge on the capacitor when the energy is stored equally between the electric and magnetic fields is
5)
Which of the following is NOT true for electromagnetic waves?

12th Standard Physics English Medium Free Online Test Creative One Mark questions with Answer Key - Part Five - by Question Bank Software - Oct 12, 2020 - View & Read

1)
What physical quantities may X and Y represent? [Y represents the first mentioned quantity].
2)
In RLC series AC circuit at resonance __________.
3)
Which of the following forms a virtual and erect image for all positions of the object?
4)
Sodium and copper have work functions of 2.3eV and 4.5eV respectively, then the ratio of the wavelengths is nearest to ___________.
5)
The de Broglie wavelength of electron accelerated with a potential V is ________

12th Standard Physics English Medium Free Online Test Creative 1 Mark questions - Part Five - by Question Bank Software - Oct 12, 2020 - View & Read

1)
The unit for electric susceptibility is
2)
In an electrical arrangement as shown the equivalent resistance between X and Y will be
3)
Parts of the energy is used in an electric motor and the remaining part of the energy is dissipated in form of _____________.
4)
The magnitude of the induced emf in a conductor depends on the _______________.
5)
Speed of electromagnetic waves through vacuum is equal to ______________.

12th Standard Physics English Medium Free Online Test Creative One Mark questions with Answer Key - Part Four - by Question Bank Software - Oct 12, 2020 - View & Read

1)
The magnitude of torque on dipole is maximum if
2)
The expression for water equivalent is _____________.
3)
For an ideal transformer __________
4)
Accelerated charges would produce _____________.
5)
_________ spectra are used for making dyes

12th Standard Physics English Medium Free Online Test Creative 1 Mark questions - Part Four - by Question Bank Software - Oct 12, 2020 - View & Read

1)
In a hydrogen atom the electron revolves around the proton in an orbit of 0.53 \(\mathring { A } \). The potential produced by the electron on the nuleus is ___________
2)
If the specific resistance of a potentiometer wire is 10^-7 Om and current flowing through it is 0.1 amp, cross-sectional area of wire is 10^-6 m², then potential gradient will be ________________.
3)
The reciprocal of conductivity is________
4)
The direction of the magnetic force on a positive charge moving in a magnetic field is given by ________________.
5)
Electric filament lamp gives rise to _______________spectrum.

12th Standard Physics English Medium Free Online Test Creative One Mark questions with Answer Key - Part Three - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Electric field intensity and electric potential are related by_________.
2)
When a current of 5 A flows through a conductor of resistance 3 \(\Omega \) the loss of power due to joule heating effect is_________
3)
Which one of the following represents current magnetic field lines?
4)
If a secondary coil has 40 turns, and a primary coil with 20 turns is charged with 50V of potential difference, then potential difference in secondary would be ________________.
5)
Electromagnetic waves are discovered by _______________.

12th Standard Physics English Medium Free Online Test Creative 1 Mark questions - Part Three - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Eight mercury droplets having a radius of 1 mm and charge of 0.066 PC each merge to form one droplet. Its potential is _____________
2)
The potential due to a single point charge falls as
3)
The emf of a battery is 3 volts and internal resistance 0.125 \(\Omega \) . The difference of potential at the terminal of battery when connected across an external resistance of 1 \(\Omega \) is ______________.
4)
If a current I is flowing in a straight wire parallel to the x-axis and magnetic field is in the y-axis then the wire experiences in _________________.
5)
The Q factor of an a.c circuit containing a resistance R, inductance L and capacitor C is ________________.

12th Standard Physics English Medium Free Online Test Creative One Mark questions with Answer Key - Part Two - by Question Bank Software - Oct 12, 2020 - View & Read

1)
The concept of 'Field' was introduced by ___________
2)
A condenser is charged to a potential of 200V and has a charge of 0.1C. The energy stored in it is _____________
3)
If the specific resistance of a potentiometer wire is 10^-7 Om and current flowing through it is 0.1 amp, cross-sectional area of wire is 10^-6 m², then potential gradient will be ________________.
4)
Which of the following is an identical?
5)
The resistance of the wire varies inversely as _________________.

12th Standard Physics English Medium Free Online Test Creative 1 Mark questions - Part Two - by Question Bank Software - Oct 12, 2020 - View & Read

1)
An uncharged metal sphere is placed between two equal and oppositely charged metal plates. The nature of lines of force will be ______________
2)
An unknown resistance is connected in parallel with a 15\(\Omega \) resistance and a 12V battery. What is the value of the unknown resistance if the current in the circuit is 2A?
3)
Consider the motion of a charged particle in a uniform magnetic field directed into the paper. If velocity v of the particle is in the plane of the paper, the charged particle will describe a _____________.
4)
In the following figure the key is dosed. Which statement is correct?
5)
If the velocity of light in a medium is 2.25 x 10⁸ ms^-1 then the refractive index of the medium will be _______________.

12th Standard Physics English Medium Free Online Test Volume 2 One Mark questions 2020 - by Question Bank Software - Oct 12, 2020 - View & Read

1)
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as plane sheet of glass. This implies that the liquid must have refractive index, ______.
2)
When light is incident on a soap film of thickness 5 x 10^–5 cm, the wavelength of light reflected maximum in the visible region is 5320 Å. Refractive index of the film will be, _____.
3)
Two plane mirrors are at 45° to each other. If an object is placed between them then the number of images will be ________________.
4)
A ray of light is incident normally on a lane mirror. The angle of reflection will be _____________.
5)
A point object 0 is placed between two plane mirrors as shown in figure. The distance by mirror M₂ from it are _____________.

12th Standard Physics English Medium Free Online Test Volume 1 One Mark questions with Answer Key 2020 - by Question Bank Software - Oct 12, 2020 - View & Read

1)
The total electric flux for the following closed surface which is kept inside water
2)
A thin conducting spherical shell of radius R has a charge Q which is uniformly distributed on its surface. The correct plot for electrostatic potential due to this spherical shell is _____.
3)
The relative permittivity of water is _______.
4)
What will happen if two conducting spheres are separately charged and then brought in contact?
5)
A non-conducting material which has no free electrons is called

12th Standard Physics English Medium Free Online Test Volume 2 One Mark questions with Answer Key 2020 - by Question Bank Software - Oct 12, 2020 - View & Read

1)
A ray of light travelling in a transparent medium of refractive index n falls, on a surface separating the medium from air at an angle of incidents of 45^o . The ray can undergo total internal reflection for the following n, ______.
2)
One of the of Young’s double slits is covered with a glass plate as shown in figure. The position of central maximum will,_____.
3)
A plane mirror produces a magnification of ____________.
4)
A plane mirror is placed at the bottom of the tank containing a liquid of refractive index J.1.P is a small object at a height h above the mirror, an observer O-vertically above P outside the liquid. See p and its image in the mirror. The apparent distance between these two will be ____________.
5)
The focal length of a convex mirror is 20 cm, its radius of the curvature will be _____________.

12th Standard Physics English Medium Free Online Test Volume 1 One Mark questions 2020 - by Question Bank Software - Oct 12, 2020 - View & Read

1)
The total electric flux for the following closed surface which is kept inside water
2)
The relative permittivity of water is _______.
3)
An isolated metal sphere of radius 'r' is given a charge' q'. The potential energy of the sphere is ____________
4)
The direction of electric field at a point the equatorial line due to an electric dipole is
5)
When three capacitors are joined in series, the total capacitance is

12th Standard Physics English Medium Free Online Test Creative One Mark questions with Answer Key - by Question Bank Software - Oct 12, 2020 - View & Read

1)
The figure shows tow parallel equipotential surface A and B kept at a small distance 'r' a part from each other. A point change of Q coulomb is taken from the surface A to B. The amount of net work done will be
2)
Eight mercury droplets having a radius of 1 mm and charge of 0.066 PC each merge to form one droplet. Its potential is _____________
3)
What will happen if two conducting spheres are separately charged and then brought in contact?
4)
Temperature co-effieient of resistance for metals is ______________.
5)
In an electrical arrangement as shown the equivalent resistance between X and Y will be

12th Standard Physics English Medium Free Online Test Creative 1 Mark questions - by Question Bank Software - Oct 12, 2020 - View & Read

1)
The relative permittivity of water is _______.
2)
The expression for electric field in vector form is
3)
A condenser of 2μF capacitance is charged steadily from 0 to 5 coulomb. Which of the following graphs correctly represents the variation of potential difference across its plates with respect to the charge on the condensor [Q = C V ]
4)
Which of the following has negative temperature coefficient of resistance?
5)
In an electrical arrangement as shown the equivalent resistance between X and Y will be

12th Standard Physics English Medium Free Online Test Book Back 1 mark questions with Answer Key - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.
2)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
3)
Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is
4)
A wire of resistance 2 ohms per meter is bent to form a circle of radius 1m. The equivalent resistance between its two diametrically opposite points, A and B as shown in the figure is
5)
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.

12th Standard Physics English Medium Free Online Test Book Back one Mark questions - by Question Bank Software - Oct 12, 2020 - View & Read

1)
If voltage applied on a capacitor is increased from V to 2V, choose the correct conclusion.
2)
Two metallic spheres of radii 1 cm and 3 cm are given charges of -1 \(\times\) 10^-2 C and 5 \(\times\) 10^-2 C respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is
3)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
4)
Two wires of A and B with circular cross section made up of the same material with equal lengths. Suppose R_A = 3 R_B, then what is the ratio of radius of wire A to that of B?
5)
The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Two - by Question Bank Software - Oct 12, 2020 - View & Read

1)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
2)
What will happen if two conducting spheres are separately charged and then brought in contact?
3)
Which of the following statement on equipotential surface is wrong?
4)
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of ______.
5)
A bar magnet of length l and magnetic moment p_m is bent in the form of an arc as shown in Figure. The new magnetic dipole moment will be

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Two - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
What will happen if two conducting spheres are separately charged and then brought in contact?
3)
In a parallel plate capacitor of capacitance C, a metal sheet is inserted between the plates, parallel to them. The thickness of the sheet is half of the separation between the plates. The capacitance now becomes
4)
A charge q₁ exerts force on charge q₂. If another charge q₃ is brought near, the force of q₁, exerted on q₂, will be
5)
By using law of conservation of electric charge balance the following equations:
₉₂U²³⁸ ⇾₉₀Th²³⁴+________.

12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
2)
The figure shows tow parallel equipotential surface A and B kept at a small distance 'r' a part from each other. A point change of Q coulomb is taken from the surface A to B. The amount of net work done will be
3)
Which one of the following relation is correct?
4)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
5)
A metallic block has no potential difference applied across it, then the mean velocity of free electrons is _____________.

12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - by Question Bank Software - Oct 12, 2020 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is
3)
The given figure is a plot of lines of force due to two charges q₁ & q₂ find out the sign of charges
4)
A condenser of 2μF capacitance is charged steadily from 0 to 5 coulomb. Which of the following graphs correctly represents the variation of potential difference across its plates with respect to the charge on the condensor [Q = C V ]
5)
Near a charged object A another earthed object B is placed. Charges are induced on B. If B is removed. After that the charge on A ________.

12th Standard Physics English Medium Model 5 Mark Creative Questions (New Syllabus 2020) - by Question Bank Software - Sep 29, 2020 - View & Read

1)
It requires 50 μJ of work to carry a 2C charge from point R to S. What is the potential difference between these points?
2)
An infinite number of charges each equal to q are placed along X-axis at x = 1, x = 2, x = 3, x = 4, x = 8 and soon. Find the electric field at the point x = 0 due to this set up of charges.
3)
Explain the variation of resistivity of conductor and semiconductor with change in temperature.
4)
Using the concept of drift velocity of charge carries in a conductor, deduce the relationship between circuit density and resistivity of the conductor?
5)
An aluminium wire of diameter 0.24 cm is connected in series to a copper wire of diameter 0.16 cm. The wires carry an electric current of 10 A. Determine the current density in aluminium wire.

12th Standard Physics English Medium Model 5 Mark Book Back Questions (New Syllabus 2020) - by Question Bank Software - Sep 29, 2020 - View & Read

1)
Calculate the electric flux through the rectangle of sides 5 cm and 10 cm kept in the region of a uniform electric field 100 NC^-1. The angle θ is 60°. If θ becomes zero, what is the electric flux?
2)
Find the equivalent capacitance between P and Q for the configuration shown below in the figure (a).
3)
Consider an electron travelling with a speed v_o and entering into a uniform electric field \(\vec{E}\) which is perpendicular to \(\vec { { v }_{ 0 } } \) as shown in the Figure. Ignoring gravity, obtain the electron’s acceleration, velocity and position as functions of time.
4)
A point charge of +10 μC is placed at a distance of 20 cm from another identical point charge of +10 μC. A point charge of -2 μC is moved from point a to b as shown in the figure. Calculate the change in potential energy of the system? Interpret your result.
5)
From the given circuit,

Find
i) Equivalent emf of the combination
ii) Equivalent internal resistance
iii) Total current
iv) Potential difference across external resistance
v) Potential difference across each cell

12th Standard Physics English Medium Sample 5 Mark Creative Questions (New Syllabus 2020) - by Question Bank Software - Sep 29, 2020 - View & Read

1)
Explain in detail the Electrostatic Potential difference between the charges.
2)
How many electrons are there in one coulomb of negative charge?
3)
In the circuit shown in figure. Find
(i) The equivalent capacitance and
(ii) The charge stored in each capacitor
4)
Explain the variation of resistivity of conductor and semiconductor with change in temperature.
5)
Two metallic wires P₁ & P₂ of the same material & same length but different cross sectional areas A₁ & A₂ are joined together & connected to a source of emf. Find the ratio of the drift velocities of free electrons in the two wires when they are connected
(i) in series &
(ii) in parallel.

12th Physics English Medium Sample 5 Mark Book Back Questions (New Syllabus 2020) - by Question Bank Software - Sep 29, 2020 - View & Read

1)
Four charges are arranged at the corners of the square PQRS of side an as shown in the figure.
(a) Find the work required to assemble these charges in the given configuration.
(b) Suppose a charge q is brought to the center of the square, by keeping the four charges fixed at the corners, how much extra work is required for this?
2)
A parallel plate capacitor has square plates of side 5 cm and separated by a distance of 1 mm.
(a) Calculate the capacitance of this capacitor.
(b) If a 10 V battery is connected to the capacitor, what is the charge stored in any one of the plates? (The value of ε_o = 8.85 x 10^-12 Nm² C^-2)
3)
Draw the free body diagram for the following charges as shown in the figure (a), (b) and (c).
4)
Calculate the resultant capacitances for each of the following combinations of capacitors.
5)
Two electric bulbs marked 20 W – 220 V and 100 W – 220 V are connected in series to 440 V supply. Which bulb will get fused?

12th Physics English Medium Important 5 Mark Creative Questions (New Syllabus 2020) - by Question Bank Software - Sep 29, 2020 - View & Read

1)
It requires 50 μJ of work to carry a 2C charge from point R to S. What is the potential difference between these points?
2)
What charge would be required to electrify a sphere of radius 25 cm. So as to get a surface charge density of \(\frac{3}{\pi}\) cm^-1?
3)
A parallel plate capacitor has plate area, 25 cm⁺² and a separation of 2 mm between the plates. The capacitor is connected to a battery of 12V. Find the charge on the capacitor.
4)
Two insulated charged copper sphere A and B have their centres separated by a distance of 50cm.
(i) What is the force of electrostatic repulsion, if the charge on each is 6.5 x 10^-7C and the radii of A and B are negligible compared to the distance of separation?
(ii) What is the force of repulsion, if each sphere is charged double the above amount and the distance between them is halved?
5)
Write mathematical relation between
(i) mobility & drift velocity of charge carriers in a conductor
(ii) mobility & relaxation time (or) mean free time.

Important 5 Mark Book Back Questions (New Syllabus 2020) - by Question Bank Software - Sep 29, 2020 - View & Read

1)
A water molecule has an electric dipole moment of 6.3 x 10^-30 Cm. A sample contains 10²² water molecules, with all the dipole moments aligned parallel to the external electric field of magnitude 3 x 10⁵ NC^-1. How much work is required to rotate all the water molecules from θ = 0° to 90°?
2)
A parallel plate capacitor filled with mica having ε_r = 5 is connected to a 10 V battery. The area of the parallel plate is 6 cm² and separation distance is 6 mm.
(a) Find the capacitance and stored charge.
(b) After the capacitor is fully charged, the battery is disconnected and the dielectric is removed carefully.
Calculate the new values of capacitance, stored energy and charge.
3)
For the given capacitor configuration
(a) Find the charges on each capacitor
(b) potential difference across them
(c) energy stored in each capacitor
4)
A battery has an emf of 12 V and connected to a resistor of 3 Ω. The current in the circuit is 3.93 A. Calculate
(a) terminal voltage and the internal resistance of the battery
(b) power delivered by the battery and power delivered to the resistor
5)
In a Wheatstone’s bridge P = 100 Ω, Q = 1000 Ω and R = 40 Ω. If the galvanometer shows zero deflection, determine the value of S.

12th Standard Physics English Medium Model 3 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Sep 01, 2020 - View & Read

1)
What happens when and electric dipole is held in a non-uniform electric field?
2)
What is dielectrics or insulators.
3)
How does one can understand the temperature dependence of resistivity of a conductor?
4)
Find the expression for the equivalent emf & internal resistance of the series combination of cells.
5)
Mention the properties of Magnetic field lines?

12th Standard Physics English Medium Model 3 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Sep 01, 2020 - View & Read

1)
Calculate the electrostatic force and gravitational force between the proton and the electron in a hydrogen atom. They are separated by a distance of 5.3 x 10^–11 m. The magnitude of charges on the electron and proton are 1.6 x 10^–19 C. Mass of the electron is m_e = 9.1 x 10^–31 kg and mass of proton is m_p = 1.6 x 10^–27 kg.
2)
Calculate the electric field due to a dipole on its axial line and equatorial plane.
3)
Obtain the expression for energy stored in the parallel plate capacitor.
4)
A potential difference across 24 Ω resistor is 12 V. What is the current through the resistor?
5)
Five resistors are connected in the configuration as shown in the figure. Calculate the equivalent resistance between the points a and b.

12th Standard Physics English Medium Sample 3 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Sep 01, 2020 - View & Read

1)
What is principle used in Microwave oven? Explain.
2)
Explain the Lightning arrester or lightning conductor.
3)
How does one can understand the temperature dependence of resistivity of a conductor?
4)
Explain Peltier effect.
5)
State that a current carrying loop behaves as a magnetic dipole. Hence write an expression for its magnetic dipole moment.

12th Standard Physics English Medium Sample 3 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Sep 01, 2020 - View & Read

1)
Calculate the number of electrons in one coulomb of negative charge.
2)
Calculate the electric field at points P, Q for the following two cases, as shown in the figure.
(a) A positive point charge +1 μC is placed at the origin.
(b) A negative point charge -2 μC is placed at the origin.
3)
Explain in detail Coulomb’s law and its various aspects.
4)
Discuss the various properties of conductors in electrostatic equilibrium.
5)
A potential difference across 24 Ω resistor is 12 V. What is the current through the resistor?

12th Standard Physics English Medium Important 3 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Sep 01, 2020 - View & Read

1)
Derive the expressions for the potential energy of a system of point charges.
2)
Explain the Lightning arrester or lightning conductor.
3)
Derive a relation between internal resisance and emf of a cell.
4)
Tabulate the difference between Coulomb's law and Biot-Savort's law.
5)
In a certain region of space, electric field \(\vec { E } \) and magnetic field \(\vec { B } \) are perpendicular to each other. An electron enters the region perpendicular to the direction of both \(\vec { B } \) & \(\vec { E } \) and moves undeflected. Find the velocity of the electron.

12th Standard Physics English Medium Important 3 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Sep 01, 2020 - View & Read

1)
Calculate the number of electrons in one coulomb of negative charge.
2)
A block of mass m carrying a positive charge q is placed on an insulated frictionless inclined plane as shown in the figure. A uniform electric field E is applied parallel to the inclined surface such that the block is at rest. Calculate the magnitude of the electric field E.
3)
Calculate the electric dipole moment for the following charge configurations.
4)
Derive an expression for the torque experienced by a dipole due to a uniform electric field.
5)
Obtain the expression for energy stored in the parallel plate capacitor.

12th Standard Physics English Medium Model 2 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Aug 29, 2020 - View & Read

1)
What is a Capacitor?
2)
Represent the variation of electric field due to point charge Q with
a) magnitude of charge Q
b) r and
c) \(\frac{1}{r^2}\) where r is the distance of the observation point from the charge graphically.
3)
How does the energy stored in a capacitor change it
(i) after disconnecting the battery, the plates of a charged capacitor are moved faster.
(ii) The battery remaining connected capacitance c ∝ \(\frac{1}{d}\), when plates of capacitor.
4)
Define instantaneous current.
5)
The resistivity of materials depends upon what parameters?

12th Standard Physics English Medium Model 2 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Aug 29, 2020 - View & Read

1)
What is meant by ‘electric field lines’?
2)
What is polarisation?
3)
Define electrical resistivity.
4)
What is Seebeck effect?
5)
State Coulomb’s inverse law.

12th Standard Physics English Medium Sample 2 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Aug 29, 2020 - View & Read

1)
What are induced dipoles.
2)
An electric dipole is held in a uniform electric field.
(i) Straight the net force acting on it is zero.
(ii) The dipole is alignment parallel to the field. find the work done in rotating it through the angle of 180^o.
3)
Two isolated metal spheres A & B have radii R & 2R respectively and same charge q. Find which of the two spheres have greater energy density just outside the surface of the sphere.
4)
A parallel plate capacitor is charged by a battery after some time, the battery is disconnected and a dielectric slab with its thickness equal to the plate so reparation is insected between the plates. How will
(i) the capacitance of the capacitor
(ii) potential difference between the plates &
(iii) the energy stored in the capacitor the affected?
Q₀ - charge; V₀ - potential difference,
C₀ - capacitance, E₀- electric field.
U₀ - energy spread, before the dielectric slab is inserted.
\({ Q }_{ 0 }={ C }_{ 0 }{ V }_{ 0 };\frac { { B }_{ 0 } }{ d } ;{ U }_{ 0 }=\frac { 1 }{ 2 } { C }_{ 0 }{ v }_{ 0 }^{ 2 }\)
5)
Gauss law is true for any closed surface, no matter what its shape or size is. Justify.

12th Standard Physics English Medium Sample 2 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Aug 29, 2020 - View & Read

1)
Write a short note on superposition principle.
2)
Define ‘electric flux’.
3)
State macroscopic form of Ohm’s law.
4)
What do you mean by internal resistance of a cell?
5)
Define magnetic dipole moment.

12th Standard Physics English Medium Important 2 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Aug 29, 2020 - View & Read

1)
What are induced dipoles.
2)
A sphere of charge +Q is fixed. A smaller sphere of charge +q is placed near the larger sphere and released from rest. The small sphere will move away from large sphere with
a. decreasing velocity & decreasing acceleration.
b. decreasing velocity & increasing acceleration.
c. decreasing velocity & constant acceleration
d. increasing velocity & decreasing acceleration
e. increasing velocity & increasing acceleration
Which of the above statement is correct? Explain.
3)
A parallel plate capacitor is charged by a battery after some time, the battery is disconnected and a dielectric slab with its thickness equal to the plate so reparation is insected between the plates. How will
(i) the capacitance of the capacitor
(ii) potential difference between the plates &
(iii) the energy stored in the capacitor the affected?
Q₀ - charge; V₀ - potential difference,
C₀ - capacitance, E₀- electric field.
U₀ - energy spread, before the dielectric slab is inserted.
\({ Q }_{ 0 }={ C }_{ 0 }{ V }_{ 0 };\frac { { B }_{ 0 } }{ d } ;{ U }_{ 0 }=\frac { 1 }{ 2 } { C }_{ 0 }{ v }_{ 0 }^{ 2 }\)
4)
How does the energy stored in a capacitor change it
(i) after disconnecting the battery, the plates of a charged capacitor are moved faster.
(ii) The battery remaining connected capacitance c ∝ \(\frac{1}{d}\), when plates of capacitor.
5)
Define mean free time \(\tau \).

12th Standard Physics English Medium Important 2 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Aug 29, 2020 - View & Read

1)
Write a short note on superposition principle.
2)
Define ‘electrostatic potential energy’.
3)
Distinguish between drift velocity and mobility.
4)
What is electric power and electric energy?
5)
What is Peltier effect?

12th Standard Physics English Medium Model 1 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Aug 25, 2020 - View & Read

1)
The figure shows tow parallel equipotential surface A and B kept at a small distance 'r' a part from each other. A point change of Q coulomb is taken from the surface A to B. The amount of net work done will be
2)
Two condensers (capacitors) of capacity C₁ and C₂ are connected in parallel. A charge Q given to then is shared. The ratio of the charges Q is _________
3)
The expression for the electric field due to a surface of total charge 'Q' is given by __________
4)
The unit for electric flux is
5)
The temperature co-efficient of resistance for alloys is _____________.

12th Standard Physics English Medium Model 1 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Aug 25, 2020 - View & Read

1)
A parallel plate capacitor stores a charge Q at a voltage V. Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?
2)
The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.
3)
Three wires of equal lengths are bent in the form of loops. One of the loops is circle, another is a semi-circle and the third one is a square. They are placed in a uniform magnetic field and same electric current is passed through them. Which of the following loop configuration will experience greater torque?
4)
A simple pendulum with charged bob is oscillating with time period T and lets θ be the angular displacement. If the uniform magnetic field switched ON in a direction perpendicular to the plane of oscillation then ___________.
5)
In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is

12th Standard Physics English Medium Sample 1 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Aug 25, 2020 - View & Read

1)
The relative permittivity of water is _______.
2)
The force experienced by a unit charge is called ____________
3)
Two charges are kept at a distance in air what should be the relative permittivity of the medium in which the two charges should be kept at the same distance so that they experience half of the force which they experienced in air?
4)
For continuous charge distributions, _____ methods can be used.
5)
Two charged bodies of charges +q, -3q are brought in contact and separated. The charges prossed by each body after separation.

12th Standard Physics English Medium Sample 1 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Aug 25, 2020 - View & Read

1)
Two points A and B are maintained at a potential of 7 V and -4 V respectively. The work done in moving 50 electrons from A to B is _______.
2)
A parallel plate capacitor stores a charge Q at a voltage V. Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?
3)
The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.
4)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.
5)
A non-conducting charged ring carrying a charge of q, mass m and radius r is rotated about its axis with constant angular speed ω. Find the ratio of its magnetic moment with angular momentum is _____.

12th Standard Physics English Medium Important 1 Mark Creative Questions (New Syllabus) 2020 - by Question Bank Software - Aug 25, 2020 - View & Read

1)
The relative permittivity of water is _______.
2)
The electric potential V as a function of distance x (metres) is given by V = ( 5x² + 10x -9) volt. The value of electric field at a point x = 1m is __________
3)
The unit for electric susceptibility is
4)
The capacitance of a parallel plate capacitor increases from 5μf of 50μf when a dielectric is filled between the plates. The permitivity of the dielectric is
5)
If the specific resistance of a potentiometer wire is 10^-7 Om and current flowing through it is 0.1 amp, cross-sectional area of wire is 10^-6 m², then potential gradient will be ________________.

12th Standard Physics English Medium Important 1 Mark Book Back Questions (New Syllabus) 2020 - by Question Bank Software - Aug 25, 2020 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
3)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
4)
What is the value of resistance of the following resistor?
5)
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.

12th standard Physics full portion important One Mark Questions - 2020 - by Question Bank Software - Mar 20, 2020 - View & Read

1)
The total electric flux for the following closed surface which is kept inside water
2)
If voltage applied on a capacitor is increased from V to 2V, choose the correct conclusion.
3)
At Infinity (i.e r = ∞), the electrostatic potential (V) is
4)
Electrostatics deals with the _________
5)
The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?

12th Physics - Recent Developments in Physics - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
Distinguish between Nanoscience and Nanotechnology.
2)
What is the difference between Nano materials and Bulk materials?
3)
Give any two examples for “Nano” in nature.
4)
Mention any two advantages and disadvantages of Robotics.
5)
Why steel is preferred in making Robots?

12th Physics Communication Systems - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
Give the factors that are responsible for transmission impairments.
2)
Distinguish between wireline and wireless communication? Specify the range of electromagnetic waves in which it is used.
3)
Explain centre frequency or resting frequency in frequency modulation.
4)
What does RADAR stand for?
5)
What do you mean by Internet of Things?

12th Physics Semiconductor Electronics - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
Distinguish between intrinsic and extrinsic semiconductors.
2)
What do you mean by doping?
3)
A diode is called as a unidirectional device. Explain.
4)
What do you mean by leakage current in a diode?
5)
Discuss the biasing polarities in an NPN and PNP transistors

12th Physics Atomic and Nuclear physics - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
What are cathode rays?
2)
Write down the postulates of Bohr atom model.
3)
What is distance of closest approach?
4)
Define atomic mass unit u.
5)
What is binding energy of a nucleus? Give its expression.

12th Physics Dual Nature of Radiation and Matter - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
Define work function of a metal. Give its unit.
2)
How does photocurrent vary with the intensity of the incident light?
3)
What is a photo cell? Mention the different types of photocells.
4)
State de Broglie hypothesis.
5)
A proton and an electron have same kinetic energy. Which one has greater de Broglie wavelength. Justify.

12th Physics Optics - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
How does an endoscope work?
2)
Arrive at lens equation from lens maker’s formula.
3)
Write a short note on quantum theory of light.
4)
Define wavefront.
5)
How does wavefront division provide coherent sources?

12th Physics Electromagnetic Waves - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
What is displacement current?
2)
What are electromagnetic waves?
3)
Write down the integral form of modified Ampere’s circuital law.
4)
Explain the concept of intensity of electromagnetic waves.
5)
What is meant by Fraunhofer lines?

12th Physics Electromagnetic Induction and Alternating Current - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
What is meant by electromagnetic induction?
2)
State Faraday’s laws of electromagnetic induction.
3)
Mention the ways of producing induced emf.
4)
What do you mean by self-induction?
5)
List out the advantages of stationary armature-rotating field system of AC generator.

12th Physics Magnetism and Magnetic Effects of Electric Current - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
What is meant by magnetic induction?
2)
Define magnetic flux.
3)
State Coulomb’s inverse law.
4)
State Biot-Savart’s law.
5)
Compare dia, para and ferro-magnetism.

12th Physics Current Electricity - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
Distinguish between drift velocity and mobility.
2)
State microscopic form of Ohm’s law.
3)
What is electric power and electric energy?
4)
Write down the various forms of expression for power in electrical circuit.
5)
What do you mean by internal resistance of a cell?

12th Physics Electrostatics - Two Marks Study Materials - by 8682895000 - Jan 22, 2020 - View & Read

1)
Write down Coulomb’s law in vector form and mention what each term represents.
2)
What are the differences between Coulomb force and gravitational force?
3)
What is meant by ‘electric field lines’?
4)
What is dielectric strength?

12th Physics - Full Portion Five Marks Questions - by 8682895000 - Jan 20, 2020 - View & Read

1)
The following figure represents the electric potential as a function of x – coordinate. Plot the corresponding electric field as a function of x.
2)
A parallel plate capacitor filled with mica having ε_r = 5 is connected to a 10 V battery. The area of the parallel plate is 6 cm² and separation distance is 6 mm.
(a) Find the capacitance and stored charge.
(b) After the capacitor is fully charged, the battery is disconnected and the dielectric is removed carefully.
Calculate the new values of capacitance, stored energy and charge.
3)
The following figure shows a complex network of conductors which can be divided into two closed loops like EACE and ABCA. Apply Kirchoff’s voltage rule(KVR)
4)
In a Wheatstone’s bridge P = 100 Ω, Q = 1000 Ω and R = 40 Ω. If the galvanometer shows zero deflection, determine the value of S.
5)
The current through an element is shown in the figure. Determine the total charge that pass through the element at a) t = 0 s, b) t = 2 s, c) t = 5s

12th Physics - Full Portion Three Marks Question - by 8682895000 - Jan 20, 2020 - View & Read

1)
Consider two point charges q₁ and q₂ at rest as shown in the figure.

They are separated by a distance of 1m. Calculate the force experienced by the two charges for the following cases:
(a) q₁ = +2μC and q₂ = +3μC
(b) q₁ = +2μC and q₂ = -3μC
(c) q₁= +2μC and q₂ = -3μC kept in water (ε_r = 80)
2)
Consider four equal charges q₁, q₂, q₃ and q₄ = q = +1 μC located at four different points on a circle of radius 1m, as shown in the figure. Calculate the total force acting on the charge q₁ due to all the other charges.
3)
(a) Calculate the electric potential at points P and Q as shown in the figure below.
(b) Suppose the charge + 9μC is replaced by - 9 μC find the electrostatic potentials at points P and Q.

(c) Calculate the work done to bring a test charge +2 μC from infinity to the point Q. Assume the charge +9 μC is held fixed at origin and +2 μC is brought from infinity to P.
4)
Define potential difference and derive.
5)
Consider a rectangular block of metal of height A, width B and length C as shown in the figure.

If a potential difference of V is applied between the two faces A and B of the block (figure (a)), the current I_AB is observed. Find the current that flows if the same potential difference V is applied between the two faces B and C of the block (figure (b)). Give your answers in terms of I_AB.

12th Physics - Full Portion Two Marks Study Materials - by 8682895000 - Jan 20, 2020 - View & Read

1)
What is an equipotential surface?
2)
Define ‘capacitance’. Give its unit.
3)
State microscopic form of Ohm’s law.
4)
Define temperature coefficient of resistance.
5)
What do you mean by internal resistance of a cell?

12th Physics - Public Exam Model Question Paper 2019 - 2020 - by Question Bank Software - Jan 17, 2020 - View & Read

1)
The force between like charges is _________.
2)
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.
3)
Three wires of equal lengths are bent in the form of loops. One of the loops is circle, another is a semi-circle and the third one is a square. They are placed in a uniform magnetic field and same electric current is passed through them. Which of the following loop configuration will experience greater torque?
4)
Above the neutral temperature the thermo emf ____________________.
5)
In a transformer, eddy current loss is minimized by using ____________.

12th Physics - Recent Developments in Physics Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
The alloys used for muscle wires in Robots are _____.
2)
The particle which gives mass to protons and neutrons are _____.
3)
__________ Scanning Electron Micrograph (SEM) showing the nano structures on the surface of a leaf from a lotus plant
4)
Best example for applications of nanotechnology is ______________.
5)
Zno is an example of __________

12th Physics - Communication Systems Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
The output transducer of the communication system converts the radio signal into ________.
2)
The signal is aff ected by noise in a communication system _____________.
3)
The variation of frequency of carrier wave with respect to the amplitude of the modulating signal is called ______.
4)
The internationally accepted frequency deviation for the purpose of FM broadcasts ____________.
5)
The frequency range of 3 MHz to 30 MHz is used for ______.

12th Physics - Semiconductor Electronics Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
The zener diode is primarily used as ______.
2)
The principle based on which a solar cell operates is______.
3)
The electrical series circuit in digital form is
4)
Which statement is incorrect regarding for p-n junction?
5)
The intrinsic semi-conductor has ______________.

12th Physics - Atomic and Nuclear Physics Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
The charge of cathode rays particle is _____.
2)
The ratio of the wavelengths radiation emitted for the transition from n = 2 to n = 1 in Li⁺⁺, He⁺and H is _____.
3)
M_p denotes the mass of the proton and M_n denotes mass of a neutron. A given nucleus of binding energy B, contains Z protons and N neutrons. The mass M(N, Z) of the nucleus is given by _____.(where c is the speed of light)
4)
The ionization energy of hydrogen atom is -13.6e V. The energy corresponding to a transition between 3rd and 4th orbit is ______________.
5)
The total energy of electrons in the ground state of a hydrogen atom is -13.6 eV. The k.E of an electron in the first excited state is ____________.

12th Physics - Dual Nature of Radiation and Matter Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
In an electron microscope, the electrons are accelerated by a voltage of 14 kV. If the voltage is changed to 224 kV, then the de Broglie wavelength associated with the electrons would _____.
2)
The threshold wavelength for a metal surface whose photoelectric work function is 3.313 eV is _____.
3)
The work function of a metal is hv₀. Light of frequency v falls on this metal. The photoelectric effect will take place only if ___________.
4)
Photo electron effect supports quantum nature of light because ___________.
5)
A charged oil drop is suspended in a uniform field of 3 x 10⁴ Vm^-1 so that it neither falls nor rises. The charge on the drop will be _____________.

12th Physics - Optics Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as plane sheet of glass. This implies that the liquid must have refractive index, ______.
2)
The radius of curvature of curved surface at a thin planoconvex lens is 10 cm and the refractive index is 1.5. If the plane surface is silvered, then the focal length will be, ______.
3)
First diffraction minimum due to a single slit of width 1.0 x 10^–5 cm is at 30^o. Then wavelength of light used is,_____.
4)
Two plane mirrors are at 45° to each other. If an object is placed between them then the number of images will be ________________.
5)
A ray of light is incident normally on a lane mirror. The angle of reflection will be _____________.

12th Physics - Electromagnetic Waves Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
In an electromagnetic wave traveling in free space the rms value of the electric field is 3 V m⁻¹. The peak value of the magnetic field is _____.
2)
During the propagation of electromagnetic waves in a medium __________________.
3)
If E = E_o sin[10⁶ x -ωt] be the electric field of a plane electromagnetic wave, the value of ω is_____.
4)
Which of the following electromagnetic waves has the highest frequency?
5)
Which of the following E.M waves has the longest wavelength?

12th Physics - Electromagnetic Induction and Alternating Current Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
2)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
3)
In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is
4)
A step-down transformer reduces the supply voltage from 220 V to 11 V and increase the current from 6 A to 100 A. Then its efficiency is
5)
In a series resonant RLC circuit, the voltage across 100 Ω resistor is 40 V. The resonant frequency ω is 250 rad/s. If the value of C is 4 µF, then the voltage across L is

12th Physics - Magnetism and Magnetic Effects of Electric Current Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
A particle having mass m and charge q accelerated through a potential difference V. Find the force experienced when it is kept under perpendicular magnetic field \(\vec { B } \).
2)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.
3)
The vertical component of Earth’s magnetic field at a place is equal to the horizontal component. What is the value of angle of dip at this place?
4)
Which one of the following represents current magnetic field lines?
5)
An electron of mass 0.90 x 10^-30kg under the action of a magnetic field moves in a circle of 2cm radius at a speed of 3 x 10⁶ m/s if a proton of mass 1.8 x 10^-27 kg was to move in a circle of the same radius in the same magnetic field, then its speed will be _______________.

12th Physics - Current Electricity Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
2)
Two wires of A and B with circular cross section made up of the same material with equal lengths. Suppose R_A = 3 R_B, then what is the ratio of radius of wire A to that of B?
3)
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.
4)
Which of the following has negative temperature coefficient of resistance?
5)
The temperature co-efficient of resistance for alloys is _____________.

12th Physics - Electrostatics Model Question Paper 1 - by 8682895000 - Jan 06, 2020 - View & Read

1)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
2)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
3)
Two points A and B are maintained at a potential of 7 V and -4 V respectively. The work done in moving 50 electrons from A to B is _______.
4)
The value of constant 'K' in coulomb law is _____________.

12th Physics - Recent Developments in Physics Model Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
The particle size of ZnO material is 30 nm. Based on the dimension it is classified as _____.
2)
The alloys used for muscle wires in Robots are _____.
3)
The technology used for stopping the brain from processing pain is _____.
4)
George Devel invented the first digitally operated programmable robot called ____________.
5)
In __________ it was established that atoms are made up of electrons, protons and neutrons

12th Physics - Communication Systems Model Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
The process of increasing the strength of a signal using an electric circuit is called ________________.
2)
Modulation is the process of superposing _______________.
3)
The device which is a combination of a receiver and a transmitter is ___________________.
4)
The maximum carrier swing allowed in frequency modulation is ________________.
5)
The resting frequency of the FM transmitter is 98.5MHz. The allowed minimum and maximum frequency on either side of the center frequency are respectively_____________.

12th Physics - Semiconductor Electronics Model Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
If a small amount of antimony (Sb) is added to germanium crystal,______.
2)
A forward biased diode is treated as ________________.
3)
C, Si and Ge have same no of valence electrons. C is an insulator because energy required to take one electron out from ______________.
4)
By adding _________ impurity in intrinsic semi conductor, p type semiconductor is made. Charge of these p type semiconductor is ____________
5)
Assertion: Base current (I_B) decreases and in turn increases the collector current.
Reason: Input signal (V_S) decreases the forward voltage across the emitter-base.
Codes:
(a) Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) Assertion and Reason are true but Reason is the false explanation of the Assertion.
(c) Assertion is true but Reason is false.
(d) Assertion is false but Reason is true.

12th Physics - Atomic and Nuclear Physics Practice Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
Suppose an alpha particle accelerated by a potential of V volt is allowed to collide with a nucleus of atomic number Z, then the distance of closest approach of alpha particle to the nucleus is _____.
2)
The charge of cathode rays particle is _____.
3)
In J.J. Thomson e/m experiment, electrons are accelerated through 2.6 kV enter the region of crossed electric field and magnetic field of strength 3.0 x 10⁴ Vm^-1 and 1.0 x 10^-3 T, respectively, and pass through it and undeflected, then the specific charge is _____.
4)
The ratio of the wavelengths radiation emitted for the transition from n = 2 to n = 1 in Li⁺⁺, He⁺and H is _____.
5)
The ground state energy of a hydrogen atom is 13.6 eV. The energy needed to ionize H₂ atom from its second excited state ______________.

12th Physics - Dual Nature of Radiation and Matter Practice Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
The wavelength λ_eof an electron and λ_p of a photon of same energy E are related by _____.
2)
In an electron microscope, the electrons are accelerated by a voltage of 14 kV. If the voltage is changed to 224 kV, then the de Broglie wavelength associated with the electrons would _____.
3)
P and E denote the linear momentum and energy of a photon. If the wavelength is decreased ____________.
4)
The work function of a metal is hv₀. Light of frequency v falls on this metal. The photoelectric effect will take place only if ___________.
5)
The minimum amount of energy required to liberate a photo electron from the metal surface is called as ________

12th Physics - Optics Sample Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
The speed of light in an isotropic medium depends on, ______.
2)
A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is, ______.
3)
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as plane sheet of glass. This implies that the liquid must have refractive index, ______.
4)
The radius of curvature of curved surface at a thin planoconvex lens is 10 cm and the refractive index is 1.5. If the plane surface is silvered, then the focal length will be, ______.
5)
To get three images of a single object, one should have two plane mirror at an angle of ______________.

12th Physics - Electromagnetic Waves Model Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
The dimension of \(\frac { 1 }{ { \mu }_{ 0 }{ \varepsilon }_{ 0 } } \) is _____.
2)
If the amplitude of the magnetic field is 3 x 10⁻⁶ T, then amplitude of the electric field for a electromagnetic waves is _____.
3)
Which of the following electromagnetic radiations is used for viewing objects through fog
4)
Assertion: Electromagnetic waves carries not only energy and momentum but also angular momentum.
Reason: Electromagnetic waves cannot be polarized.
Codes:
(a) Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) Assertion and Reason are true but Reason is the false explanation of the Assertion.
(c) Assertion is true but Reason is false.
(d) Assertion is false but Reason is true.
5)
Assertion: Microwaves do not obey reflection and polarization.
Reason: Gamma rays are used in radiotherapy for cancer treatment.
Codes:
(a) Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) Assertion and Reason are true but Reason is the false explanation of the Assertion.
(c) Assertion is true but Reason is false.
(d) Assertion is false but Reason is true.

12th Physics Electromagnetic Induction and Alternating Current Model Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
An electron moves on a straight line path XY as shown in the figure. The coil abcd is adjacent to the path of the electron. What will be the direction of current, if any, induced in the coil?
2)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
3)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
4)
The current i flowing in a coil varies with time as shown in the figure. The variation of induced emf with time would be
5)
\(\frac{20}{\pi^2}H\) inductor is connected to a capacitor of capacitance C. The value of C in order to impart maximum power at 50 Hz is

12th Physics - Magnetism and Magnetic Effects of Electric Current Model Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
The magnetic field at the centre O of the following current loop is
2)
A particle having mass m and charge q accelerated through a potential difference V. Find the force experienced when it is kept under perpendicular magnetic field \(\vec { B } \).
3)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.
4)
What is meant by magnetic induction?
5)
Define magnetic flux.

12th Physics - Current Electricity Model Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?
2)
A wire connected to a power supply of 230 V has power dissipation P₁. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is P₂. The ratio \(\frac{P_2}{P_1}\) is ______.
3)
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.
4)
The temperature coefficient of resistance of a wire is 0.00125 per °C. At 20°C, its resistance is 1 Ω. The resistance of the wire will be 2 Ω at ______.
5)
The emf of a battery is 3 volts and internal resistance 0.125 \(\Omega \) . The difference of potential at the terminal of battery when connected across an external resistance of 1 \(\Omega \) is ______________.

12th Standard Physics - Electrostatics Model Question Paper - by Question Bank Software - Jan 02, 2020 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
3)
The relative permittivity of water is _______.
4)
An uncharged metal sphere is placed between two equal and oppositely charged metal plates. The nature of lines of force will be ______________

12th Physics - Electrostatics Model Question Paper - by Question Bank Software - Dec 30, 2019 - View & Read

1)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
2)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.
3)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
4)
Rank the electrostatic potential energies for the given system of charges in increasing order
5)
A parallel plate capacitor stores a charge Q at a voltage V. Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?

12th Physics - Recent Developments in Physics Model Question Paper - by Question Bank Software - Dec 03, 2019 - View & Read

1)
The alloys used for muscle wires in Robots are _____.
2)
The gravitational waves were theoretically proposed by _____.
3)
__________ Scanning Electron Micrograph (SEM) showing the nano structures on the surface of a leaf from a lotus plant
4)
_______ is synthesized top down approach
5)
Give any two examples for “Nano” in nature.

12th Physics - Communication Systems Model Question Paper - by Question Bank Software - Dec 03, 2019 - View & Read

1)
The signal is aff ected by noise in a communication system _____________.
2)
The frequency range of 3 MHz to 30 MHz is used for ______.
3)
In a video signal for transmission of picture what value of bandwidth is used in communication system?
4)
Which of the following is an example of breadcast made of communication?
5)
The radio waves of frequency 30 MHz to 300 MHz belong to _______________.

12th Physics - Semiconductor Electronics Model Question Paper - by Question Bank Software - Dec 03, 2019 - View & Read

1)
The zener diode is primarily used as ______.
2)
The principle based on which a solar cell operates is______.
3)
The specific characteristic of a common emitter amplifier is _______________.
4)
By adding _________ impurity in intrinsic semi conductor, p type semiconductor is made. Charge of these p type semiconductor is ____________
5)
The intrinsic semi-conductor has ______________.

12th Physics - Atomic and Nuclear Physics Model Question Paper - by Question Bank Software - Dec 03, 2019 - View & Read

1)
The electric potential of an electron is given by \(V={ V }_{ 0 } \ In\left( \frac { r }{ { r }_{ 0 } } \right) \), where r₀ is a constant. If Bohr atom model is valid, then variation of radius of n^th orbit r_n with the principal quantum number n is _____.
2)
A radioactive nucleus (initial mass number A and atomic number Z) emits two α-particles and 2 positons. The ratio of number of neutrons to that of proton in the final nucleus will be _____.
3)
The half-life period of a radioactive element A is same as the mean life time of another radioactive element B. Initially both have the same number of atoms. Then _____.
4)
The ionization energy of hydrogen atom is -13.6e V. The energy corresponding to a transition between 3rd and 4th orbit is ______________.
5)
The total energy of electrons in the ground state of a hydrogen atom is -13.6 eV. The k.E of an electron in the first excited state is ____________.

12th Physics - Dual Nature of Radiation and Matter Model Question Paper - by Question Bank Software - Dec 03, 2019 - View & Read

1)
In an electron microscope, the electrons are accelerated by a voltage of 14 kV. If the voltage is changed to 224 kV, then the de Broglie wavelength associated with the electrons would _____.
2)
In photoelectric emission, a radiation whose frequency is 4 times threshold frequency of a certain metal is incident on the metal. Then the maximum possible velocity of the emitted electron will be _____.
3)
The threshold wavelength for a metal surface whose photoelectric work function is 3.313 eV is _____.
4)
The work functions for metals A, B and C are 1.92 eV, 2.0 eV and 5.0 eV respectively. The metal/metals which will emit photoelectrons for a radiation of wavelength 4100 Å is/are _____.
5)
Light of wavelength falls on a metal having work function \(\frac { { h }_{ c } }{ { \lambda }_{ 0 } } \). Photo electric effect will place only if __________.

12th Physics - Optics Model Question Paper - by Question Bank Software - Dec 03, 2019 - View & Read

1)
If the velocity and wavelength of light in air is V_a and λ_a and that in water is V_w and λ_w, then the refractive index of water is______.
2)
Stars twinkle due to, ______.
3)
A ray of light travelling in a transparent medium of refractive index n falls, on a surface separating the medium from air at an angle of incidents of 45^o . The ray can undergo total internal reflection for the following n, ______.
4)
A man of length h requires a mirror of length at least equal to, to see his own complete image is _______________.
5)
A man runs towards a mirror at a speed 15m/s. The speed of the image relative to the man is _______________.

12th Physics - Electromagnetic Waves Model Question Paper - by Question Bank Software - Nov 27, 2019 - View & Read

1)
The electric and the magnetic fields, associated with an electromagnetic wave, propagating along negative X axis can be represented by _____.
2)
During the propagation of electromagnetic waves in a medium __________________.
3)
Which one of them is used to produce a propagating electromagnetic wave?
4)
Which of the following E.M waves has the longest wavelength?
5)
If the velocity of light in a medium is 2.25 x 10⁸ ms^-1 then the refractive index of the medium will be _______________.

12th Physics - Electromagnetic Induction and Alternating Current Model Question Paper - by Question Bank Software - Nov 27, 2019 - View & Read

1)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
2)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
3)
In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is
4)
The self-inductance of a straight conductor is ________________.
5)
If a secondary coil has 40 turns, and a primary coil with 20 turns is charged with 50V of potential difference, then potential difference in secondary would be ________________.

12th Physics - Magnetism and Magnetic Effects of Electric Current Model Question Paper - by Question Bank Software - Nov 27, 2019 - View & Read

1)
A particle having mass m and charge q accelerated through a potential difference V. Find the force experienced when it is kept under perpendicular magnetic field \(\vec { B } \).
2)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.
3)
A wire of length l carrying a current I along the Y direction is kept in a magnetic field is given by \(\vec { B } =\frac { \beta }{ \sqrt { 3 } } =(\hat { i } +\hat { j } +\hat { k } )T.\) The magnitude of Lorentz force acting on the wire is _____.
4)
The direction of the magnetic force on a positive charge moving in a magnetic field is given by ________________.
5)
If a current I is flowing in a straight wire parallel to the x-axis and magnetic field is in the y-axis then the wire experiences in _________________.

12th Physics - Current Electricity Important Questions - by Question Bank Software - Nov 21, 2019 - View & Read

1)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
2)
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.
3)
The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.
4)
Which of the following has negative temperature coefficient of resistance?
5)
The temperature co-efficient of resistance for alloys is _____________.

12th Physics - Electrostatics Important Questions - by Question Bank Software - Nov 21, 2019 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
The total electric flux for the following closed surface which is kept inside water
3)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
4)
The relative permittivity of water is _______.

12th Physics Half Yearly Model Question Paper 2019 - by Question Bank Software - Nov 12, 2019 - View & Read

1)
Two points A and B are maintained at a potential of 7 V and -4 V respectively. The work done in moving 50 electrons from A to B is _______.
2)
Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is
3)
A resistance of a metal wire of length AB is 2\(\Omega \). Another wire of length PQ of the same metal with twice the diameter of the wire AB is found to have the same resistance of 2\(\Omega \). What is the length of PQ?
4)
The reciprocal of the resistance is__________
5)
A circular coil of radius 5 cm and 50 turns carries a current of 3 ampere. The magnetic dipole moment of the coil is nearly ____.

12th Physics - Electromagnetic waves One Mark Questions with Answer - by Question Bank Software - Nov 05, 2019 - View & Read

1)
Which of the following electromagnetic radiations is used for viewing objects through fog
2)
If E = E_o sin[10⁶ x -ωt] be the electric field of a plane electromagnetic wave, the value of ω is_____.
3)
The electric and magnetic fields of an electromagnetic wave are _____.
4)
The wavelength range of ultra violet radiation is _________________.
5)
The phase and orientation of the magnetic vector associated with electromagnetic oscillations differ respectively from those of the corresponding electric vectors by _______________.

12th Physics - Electromagnetic Induction and Alternating Current One Mark Questions with Answer - by Question Bank Software - Nov 05, 2019 - View & Read

1)
An electron moves on a straight line path XY as shown in the figure. The coil abcd is adjacent to the path of the electron. What will be the direction of current, if any, induced in the coil?
2)
Electromagnetic induction is-not used in ___________________.
3)
Lenz's law is in accordance with the law of ________________.
4)
Which of the following cannot be stepped up in a transformer?
5)
If a secondary coil has 40 turns, and a primary coil with 20 turns is charged with 50V of potential difference, then potential difference in secondary would be ________________.

12th Physics - Magnetism and Magnetic Effects of Electric Current One Mark Questions with Answer - by Question Bank Software - Nov 05, 2019 - View & Read

1)
The most suitable metal for permanent magnet is ______________.
2)
The direction of the magnetic force on a positive charge moving in a magnetic field is given by ________________.
3)
Lorentz force generally refers to force experienced by a charge due to combined action of _________________.
4)
Two thin long parallel wires separated by a distance are carrying current 1 amp each. The magnitude of the force per unit length excited by one wire on the other is ____________.
5)
At a given place the horizontal component of the earth's field is 0.2 x 10^-4 Tesla. If a vertical wire carries a current of 30A upward, what is the magnitude and direction of the force on 1m of wire?

12th Physics - Current Electricity One Mark Questions with Answer - by Question Bank Software - Nov 05, 2019 - View & Read

1)
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.
2)
There is a current of 1.0 A in the circuit shown below. What is the resistance of P ?
3)
The colour code on a carbon resistor is red - red - black. The resistance of the resistor is ___________.
4)
A square aluminum rod is 1 m long and 5 mm on edge. What must be the radius of another aluminum rod whose length is 1 m and which has the same resistance as that of square Aluminum rod?
5)
Five 3 resistances are arranged in a polygon (5 sides). What is the resistance between any two corners?

12th Physics - Electrostatics One Marks Question with Answer - by Question Bank Software - Nov 05, 2019 - View & Read

1)
An isolated metal sphere of radius 'r' is given a charge' q'. The potential energy of the sphere is ____________
2)
Charge per unit volume is called _____________
3)
The expression for the electric field due to a surface of total charge 'Q' is given by __________
4)
The electric flux is negative, if the angle between \(\overset { \rightarrow }{ dA } \) and \(\overset { \rightarrow }{ E } \) is
5)
In the given cricuit the effective capacitance between A and B will be

12th Physics - Semiconductor Electronics Five Marks Questions - by Question Bank Software - Nov 04, 2019 - View & Read

1)
The given circuit has two ideal diodes connected as shown in figure below. Calculate the current flowing through the resistance R₁.
2)
Four silicon diodes and a 10 Ω resistor are connected as shown in figure below. Each diode has a resistance of 1Ω. Find the current flows through the 10Ω resistor.
3)
A transistor having α = 0.99 and V_BE = 0.7V, is connected in the common-cmiitter configuration as shown in figure. If the transister is in saturation region, find the value of the collector current.
4)
In the circuit shown in the figure, the BJT has a current gain (β) of 50. For an emitter-base voltage V_EB = 600 mV, calculate the emitter-collector voltage V_EC(in volts).

12th Physics - Atomic and Nuclear Physics Five Marks Questions - by Question Bank Software - Nov 04, 2019 - View & Read

1)
Assuming that energy released by the fission of a single \(_{ 92 }^{ 235 }{ U }\) nucleus is 200MeV, calculate the number of fissions per second required to produce 1-watt power.
2)
Keezhadi ((கீழடி),a small hamlet, has become one of the very important archaeological places of Tamilnadu. It is located in Sivagangai district. A lot of artefacts (gold coins, pottery, beads, iron tools, jewellery and charcoal, etc.) have been unearthed in Keezhadi which have given substantial evidence that an ancient urban civilization had thrived on the banks of river Vaigai. To determine the age of those materials, the charcoal of 200 g sent for carbon dating is given in the following figure (b). The activity of \(_{ 6 }^{ 14 }{ C }\) is found to be 37 decays/s. Calculate the age of charcoal.

Figure (a) Keezhadi – excavation site

Figure (b) – Characol which was sent for carbon dating
3)
Calculate the amount of energy released when 1 kg of \(_{ 92 }^{ 235 }{ U }\) undergoes fission reaction.
4)
Explain the results of Rutherford α-particle scattering experiment.
5)
Write the application of alpha decay in smoke detectors.

12th Physics - Dual Nature of Radiation and Matter Five Marks Questions - by Question Bank Software - Nov 04, 2019 - View & Read

1)
Calculate the energies of the photons associated with the following radiation:
(i) violet light of 413 nm
(ii) X-rays of 0.1 nm
(iii) radio waves of 10 m.
2)
A 150 W lamp emits light of mean wavelength of 5500 Å. If the efficiency is 12%, find out the number of photons emitted by the lamp in one second.
3)
How many photons of frequency 10¹⁴ Hz will make up 19.86 J of energy?
4)
When a 6000Å light falls on the cathode of a photo cell, photoemission takes place. If a potential of 0.8 V is required to stop emission of electron, then determine the
(i) frequency of the light
(ii) energy of the incident photon
(iii) work function of the cathode material
(iv) threshold frequency and
(v) net energy of the electron after it leaves the surface.
5)
A 3310 Å photon liberates an electron from a material with energy 3 x10^-19J while another 5000 Å photon ejects an electron with energy 0.972 x 10^-19 J from the same material. Determine the value of Planck’s constant and the threshold wavelength of the material.

12th Physics - Optics Five Marks Questions - by Question Bank Software - Nov 04, 2019 - View & Read

1)
If the distance D between an object and screen is greater than 4 times the focal length f of a convex lens, then there are two positions for which the lens forms an enlarged image and a diminished image respectively. This method is called conjugate foci method. If d is the distance between the two positions of the lens, obtain the equation for focal length of the convex lens.
2)
A compound microscope has a magnifying power of 100 when the image is formed at infinity. The objective has a focal length of 0.5 cm and the tube length is 6.5 cm. What is the focal length of the eyepiece.
3)
Two light sources with amplitudes 5 units and 3 units respectively interfere with each other. Calculate the ratio of maximum and minimum intensities.
4)
Two light sources of equal amplitudes interfere with each other. Calculate the ratio of maximum and minimum intensities.
5)
A monochromatic light of wavelength 5000 Å passes through a single slit producing diffraction pattern for the central maximum as shown in the figure. Determine the width of the slit.

12th Physics - Semiconductor Electronics Three Marks Questions - by Question Bank Software - Nov 04, 2019 - View & Read

1)
Explain the formation of depletion region and barrier potential in PN junction diode.
2)
Draw the circuit diagram of a half-wave rectifier and explain its working.
3)
Explain the construction and working of a full wave rectifier
4)
Write a note on photodiode.

12th Physics - Atomic and Nuclear physics Three Marks Questions - by Question Bank Software - Nov 04, 2019 - View & Read

1)
Explain the J.J. Thomson experiment to determine the specific charge of electron.
2)
Discuss the Millikan’s oil drop experiment to determine the charge of an electron.
3)
Explain the idea of carbon dating.
4)
Discuss the process of nuclear fission and its properties.
5)
Find the (i) angular momentum (ii) velocity of the electron revolving in the 5^th orbit of hydrogen atom.
(h = 6.6 x 10^–34 Js, m = 9.1 x 10^–31 kg)

12th Physics - Dual Nature of Radiation and Matter Three Marks Questions - by Question Bank Software - Nov 04, 2019 - View & Read

1)
What do you mean by electron emission? Explain briefly various methods of electron emission.
2)
Briefly discuss the observations of Hertz, Hallwachs and Lenard.
3)
Explain the effect of potential difference on photoelectric current.
4)
Explain how frequency of incident light varies with stopping potential.
5)
List out the laws of photo electric effect.

12th Physics - Optics Three Marks Questions - by Question Bank Software - Nov 04, 2019 - View & Read

1)
Obtain the equation for resultant intensity due to interference of light.
2)
Explain the Young’s double slit experimental setup and obtain the equation for path difference.
3)
Discuss the interference in thin films and obtain the equations for constructive and destructive interference for transmitted and reflected light.
4)
Obtain the equation for of microscope.
5)
Discuss about astronomical telescope.

12th Physics - Semiconductor Electronics Two Marks Questions - by Question Bank Software - Nov 02, 2019 - View & Read

1)
Define electron motion in a semiconductor.
2)
Distinguish between intrinsic and extrinsic semiconductors.
3)
What do you mean by doping?
4)
How electron-hole pairs are created in a semiconductor material?
5)
A diode is called as a unidirectional device. Explain.

12th Physics - Atomic and Nuclear Physics Two Marks Questions - by Question Bank Software - Nov 02, 2019 - View & Read

1)
What is meant by excitation energy?
2)
What is distance of closest approach?
3)
Define impact parameter.
4)
Calculate the energy equivalent of 1 atomic mass unit.
5)
Give the physical meaning of binding energy per nucleon.

12th Physics Dual Nature of Radiation and Matter Two Marks Question - by Question Bank Software - Nov 02, 2019 - View & Read

1)
Why do metals have a large number of free electrons?
2)
Define work function of a metal. Give its unit.
3)
What is photoelectric effect?
4)
How does photocurrent vary with the intensity of the incident light?
5)
Give the definition of intensity of light according to quantum concept and its unit.

12th Physics - Optics Two Marks Questions - by Question Bank Software - Nov 02, 2019 - View & Read

1)
What is Snell’s window?
2)
Write a note on optical fibre.
3)
What are primary focus and secondary focus of a lens?
4)
What are the sign conventions followed for lenses?
5)
What is Rayleigh's scattering?

12th Physics - Recent Developments in Physics One Mark Questions with Answer - by Question Bank Software - Nov 01, 2019 - View & Read

1)
The particle size of ZnO material is 30 nm. Based on the dimension it is classified as _____.
2)
Which one of the following is the natural nanomaterial.
3)
The blue print for making ultra durable synthetic material is mimicked from _____.
4)
The method of making nanomaterial by assembling the atoms is called _____.
5)
“Sky wax” is an application of nano product in the field of _____.

12th Physics - Semiconductor Electronics One Mark Questions with Answer - by Question Bank Software - Nov 01, 2019 - View & Read

1)
The barrier potential of a silicon diode is approximately, ______.
2)
If a small amount of antimony (Sb) is added to germanium crystal,______.
3)
A forward biased diode is treated as ________________.
4)
If a positive half-wave rectified voltage is fed to a load resistor, for which part of a cycle there will be current flow through the load?
5)
The zener diode is primarily used as ______.

12th Physics - Atomic and Nuclear physics One Mark Questions with Answer - by Question Bank Software - Nov 01, 2019 - View & Read

1)
Suppose an alpha particle accelerated by a potential of V volt is allowed to collide with a nucleus of atomic number Z, then the distance of closest approach of alpha particle to the nucleus is _____.
2)
In a hydrogen atom, the electron revolving in the fourth orbit, has angular momentum equal to _____.
3)
Atomic number of H-like atom with ionization potential 122.4 V for n = 1 is _____.
4)
The ratio between the radius of first three orbits of hydrogen atom is _____.
5)
The charge of cathode rays particle is _____.

12th Physics - Dual Nature of Radiation and Matter One Mark Questions with Answer - by Question Bank Software - Nov 01, 2019 - View & Read

1)
The wavelength λ_eof an electron and λ_p of a photon of same energy E are related by _____.
2)
In an electron microscope, the electrons are accelerated by a voltage of 14 kV. If the voltage is changed to 224 kV, then the de Broglie wavelength associated with the electrons would _____.
3)
The wave associated with a moving particle of mass 3 x 10^–6 g has the same wavelength as an electron moving with a velocity 6 x 10⁶ ms^-1. The velocity of the particle is _____.
4)
When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential is \(\frac{V}{4}\). The threshold wavelength for the metallic surface is _____.
5)
If a light of wavelength 330 nm is incident on a metal with work function 3.55 eV, the electrons are emitted. Then the wavelength of the wave associated with the emitted electron is _____.(Take h = 6.6 x 10^–34 Js)

12th Physics - Optics One Mark Questions with Answer - by Question Bank Software - Nov 01, 2019 - View & Read

1)
The speed of light in an isotropic medium depends on, ______.
2)
A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is, ______.
3)
An object is placed in front of a convex mirror of focal length off and the maximum and minimum distance of an object from the mirror such that the image formed is real and magnified.
4)
For light incident from air on a slab of refractive index 2, the maximum possible angle of refraction is, ______.
5)
If the velocity and wavelength of light in air is V_a and λ_a and that in water is V_w and λ_w, then the refractive index of water is______.

12th Standard Physics - Recent Developments in Physics Model Question Paper - by Question Bank Software - Oct 30, 2019 - View & Read

1)
The particle size of ZnO material is 30 nm. Based on the dimension it is classified as _____.
2)
Which one of the following is the natural nanomaterial.
3)
The blue print for making ultra durable synthetic material is mimicked from _____.
4)
The method of making nanomaterial by assembling the atoms is called _____.
5)
“Sky wax” is an application of nano product in the field of _____.

12th Standard Physics - Communication Systems Model Question Paper - by Question Bank Software - Oct 30, 2019 - View & Read

1)
The output transducer of the communication system converts the radio signal into ________.
2)
The signal is aff ected by noise in a communication system _____________.
3)
The variation of frequency of carrier wave with respect to the amplitude of the modulating signal is called ______.
4)
The internationally accepted frequency deviation for the purpose of FM broadcasts ____________.
5)
The frequency range of 3 MHz to 30 MHz is used for ______.

12th Standard Physics - Semiconductor Electronics Model Question Paper - by Question Bank Software - Oct 30, 2019 - View & Read

1)
The barrier potential of a silicon diode is approximately, ______.
2)
If a small amount of antimony (Sb) is added to germanium crystal,______.
3)
A forward biased diode is treated as ________________.
4)
If a positive half-wave rectified voltage is fed to a load resistor, for which part of a cycle there will be current flow through the load?
5)
The zener diode is primarily used as ______.

12th Physics - Atomic and Nuclear Physics Model Question Paper - by Question Bank Software - Oct 30, 2019 - View & Read

1)
In a hydrogen atom, the electron revolving in the fourth orbit, has angular momentum equal to _____.
2)
Atomic number of H-like atom with ionization potential 122.4 V for n = 1 is _____.
3)
If the nuclear radius of ²⁷Al is 3.6 fermi, the approximate nuclear radius of ⁶⁴Cu, in femi is _____.
4)
The nucleus is approximately spherical in shape. Then the surface area of nucleus having mass number A varies as _____.
5)
M_p denotes the mass of the proton and M_n denotes mass of a neutron. A given nucleus of binding energy B, contains Z protons and N neutrons. The mass M(N, Z) of the nucleus is given by _____.(where c is the speed of light)

12th Physics - Dual Nature of Radiation and Matter Model Question Paper - by Question Bank Software - Oct 30, 2019 - View & Read

1)
The wavelength λ_eof an electron and λ_p of a photon of same energy E are related by _____.
2)
In an electron microscope, the electrons are accelerated by a voltage of 14 kV. If the voltage is changed to 224 kV, then the de Broglie wavelength associated with the electrons would _____.
3)
The wave associated with a moving particle of mass 3 x 10^–6 g has the same wavelength as an electron moving with a velocity 6 x 10⁶ ms^-1. The velocity of the particle is _____.
4)
When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential is \(\frac{V}{4}\). The threshold wavelength for the metallic surface is _____.
5)
If a light of wavelength 330 nm is incident on a metal with work function 3.55 eV, the electrons are emitted. Then the wavelength of the wave associated with the emitted electron is _____.(Take h = 6.6 x 10^–34 Js)

12th Physics - Optics Model Question Paper - by Question Bank Software - Oct 30, 2019 - View & Read

1)
For light incident from air on a slab of refractive index 2, the maximum possible angle of refraction is, ______.
2)
If the velocity and wavelength of light in air is V_a and λ_a and that in water is V_w and λ_w, then the refractive index of water is______.
3)
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as plane sheet of glass. This implies that the liquid must have refractive index, ______.
4)
The radius of curvature of curved surface at a thin planoconvex lens is 10 cm and the refractive index is 1.5. If the plane surface is silvered, then the focal length will be, ______.
5)
A plane glass is placed over a various coloured letters (violet, green, yellow, red) The letter which appears to be raised more is _____.

12th Standard Physics - Term II Model Question Paper - by Pavithra - Karaikkudi - Oct 29, 2019 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
3)
Two wires of A and B with circular cross section made up of the same material with equal lengths. Suppose R_A = 3 R_B, then what is the ratio of radius of wire A to that of B?
4)
In Joule’s heating law, when R and t are constant, if the H is taken along the y axis and I² along the x axis, the graph is ______.
5)
Three wires of equal lengths are bent in the form of loops. One of the loops is circle, another is a semi-circle and the third one is a square. They are placed in a uniform magnetic field and same electric current is passed through them. Which of the following loop configuration will experience greater torque?

12th Standard Physics - Electromagnetic waves Model Question Paper - by Pavithra - Karaikkudi - Oct 09, 2019 - View & Read

1)
The dimension of \(\frac { 1 }{ { \mu }_{ 0 }{ \varepsilon }_{ 0 } } \) is _____.
2)
Which of the following is false for electromagnetic waves
3)
The electric and the magnetic fields, associated with an electromagnetic wave, propagating along negative X axis can be represented by _____.
4)
In an electromagnetic wave traveling in free space the rms value of the electric field is 3 V m⁻¹. The peak value of the magnetic field is _____.
5)
Which of the following is an electromagnetic wave?

12th Standard Physics Practice Question Paper 2019-2020 - by QB365 School - Oct 03, 2019 - View & Read

12th Standard Physics - Electromagnetic Induction and Alternating Current Model Question Paper - by Pavithra - Karaikkudi - Oct 01, 2019 - View & Read

1)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
2)
In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is
3)
In an electrical circuit, R, L, C, and AC voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and current in the circuit is \(\frac{\pi}{3}\). Instead, if C is removed from the circuit, the phase difference is again \(\frac{\pi}{3}\). The power factor of the circuit is
4)
An inductor 20 mH, a capacitor 50 μF and a resistor 40Ω are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is
5)
\(\frac{20}{\pi^2}H\) inductor is connected to a capacitor of capacitance C. The value of C in order to impart maximum power at 50 Hz is

12th Standard Physics - Magnetism and Magnetic Effects of Electric Current Model Question Paper - by Pavithra - Karaikkudi - Oct 01, 2019 - View & Read

1)
A circular coil of radius 5 cm and 50 turns carries a current of 3 ampere. The magnetic dipole moment of the coil is nearly ____.
2)
A wire of length l carrying a current I along the Y direction is kept in a magnetic field is given by \(\vec { B } =\frac { \beta }{ \sqrt { 3 } } =(\hat { i } +\hat { j } +\hat { k } )T.\) The magnitude of Lorentz force acting on the wire is _____.
3)
The vertical component of Earth’s magnetic field at a place is equal to the horizontal component. What is the value of angle of dip at this place?
4)
The most suitable metal for permanent magnet is ______________.
5)
When current is doubled deflection is also doubled in ______________.

12th Standard Physics - Electromagnetic Waves Three Marks Questions - by Question Bank Software - Sep 30, 2019 - View & Read

1)
The relative magnetic permeability of the medium is 2.5 and the relative electrical permittivity of the medium is 2.25. Compute the refractive index of the medium.
2)
Write down Maxwell equations in integral form.
3)
Write down the properties of electromagnetic waves.
4)
Discuss the source of electromagnetic waves.
5)
Explain the types of emission spectrum.

12th Standard Physics - Electromagnetic Induction and Alternating Current Three Marks Questions - by Question Bank Software - Sep 30, 2019 - View & Read

1)
A cylindrical bar magnet is kept along the axis of a circular solenoid. If the magnet is rotated about its axis, find out whether an electric current is induced in the coil.
2)
A closed coil of 40 turns and of area 200 cm², is rotated in a magnetic field of flux density 2 Wb m^–2. It rotates from a position where its plane makes an angle of 30^o with the field to a position perpendicular to the field in a time 0.2 s. Find the magnitude of the emf induced in the coil due to its rotation.
3)
A straight conducting wire is dropped horizontally from a certain height with its length along east-west direction. Will an emf be induced in it? Justify your answer.
4)
A conducting rod of length 0.5 m falls freely from the top of a building of height 7.2 m at a place in Chennai where the horizontal component of Earth’s magnetic field is 4.04 × 10^–5 T. If the length of the rod is perpendicular to Earth’s horizontal magnetic field, find the emf induced across the conductor when the rod is about to touch the ground. (Assume that the rod falls down with constant acceleration of 10 m s^–2)
5)
A copper rod of length l rotates about one of its ends with an angular velocity ω in a magnetic field B as shown in the figure. The plane of rotation is perpendicular to the field. Find the emf induced between the two ends of the rod.

12th Standard Physics - Magnetism and Magnetic Effects of Electric Current Three Marks Questions - by Question Bank Software - Sep 30, 2019 - View & Read

1)
The repulsive force between two magnetic poles in air is 9 x 10^–3 N. If the two poles are equal in strength and are separated by a distance of 10 cm, calculate the pole strength of each pole.
2)
A short bar magnet has a magnetic moment of 0.5 J T^–1. Calculate magnitude and direction of the magnetic field produced by the bar magnet which is kept at a distance of 0.1 m from the centre of the bar magnet along
(a) axial line of the bar magnet and
(b) normal bisector of the bar magnet.
3)
Compute the intensity of magnetisation of the bar magnet whose mass, magnetic moment and density are 200 g, 2 A m² and 8 g cm^–3, respectively.
4)
Using the relation \(\overset { \rightarrow }{ B } =\mu _{ ° }(\overset { \rightarrow }{ H+ } \overset { \rightarrow }{ M } )\) show that \({ x }_{ m }={ \mu }_{ r }-{ 1 }\)
5)
The magnetic field shown in the figure is due to the current carrying wire. In which direction does the current flow in the wire?

12th Physics - Current Electricity Three Marks Questions - by Question Bank Software - Sep 30, 2019 - View & Read

1)
If an electric field of magnitude 570 N C^–1, is applied in the copper wire, find the acceleration experienced by the electron.
2)
A copper wire of cross-sectional area 0.5 mm² carries a current of 0.2 A. If the free electron density of copper is 8.4 x 10²⁸m^-3 then compute the drift velocity of free electrons.
3)
A potential difference across 24 Ω resistor is 12 V. What is the current through the resistor?
4)
Describe the microscopic model of current and obtain general form of Ohm’s law.
5)
Explain the equivalent resistance of a series and parallel resistor network.

12th Physics - Electrostatics Three Marks Questions - by Question Bank Software - Sep 30, 2019 - View & Read

1)
Calculate the electrostatic force and gravitational force between the proton and the electron in a hydrogen atom. They are separated by a distance of 5.3 x 10^–11 m. The magnitude of charges on the electron and proton are 1.6 x 10^–19 C. Mass of the electron is m_e = 9.1 x 10^–31 kg and mass of proton is m_p = 1.6 x 10^–27 kg.
2)
Consider four equal charges q₁, q₂, q₃ and q₄ = q = +1 μC located at four different points on a circle of radius 1m, as shown in the figure. Calculate the total force acting on the charge q₁ due to all the other charges.
3)
Obtain the expression for capacitance for a parallel plate capacitor.
4)
Obtain the expression for energy stored in the parallel plate capacitor.
5)
Explain in detail the effect of a dielectric placed in a parallel plate capacitor.

12th Physics - Current Electricity Model Question Paper - by Pavithra - Karaikkudi - Sep 27, 2019 - View & Read

1)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
2)
Two wires of A and B with circular cross section made up of the same material with equal lengths. Suppose R_A = 3 R_B, then what is the ratio of radius of wire A to that of B?
3)
The temperature coefficient of resistance of a wire is 0.00125 per °C. At 20°C, its resistance is 1 Ω. The resistance of the wire will be 2 Ω at ______.
4)
In Joule’s heating law, when R and t are constant, if the H is taken along the y axis and I² along the x axis, the graph is ______.
5)
The temperature co-efficient of resistance for alloys is _____________.

12th Standard Physics - Electrostatics Model Question Paper - by Pavithra - Karaikkudi - Sep 27, 2019 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
3)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
4)
Two metallic spheres of radii 1 cm and 3 cm are given charges of -1 \(\times\) 10^-2 C and 5 \(\times\) 10^-2 C respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is
5)
The electrostatic force obeys _______.

12th Physics Quarterly Exam Question Paper 2019 - by Question Bank Software - Sep 21, 2019 - View & Read

12th Physics - Term 1 Model Question Paper - by Pavithra - Karaikkudi - Sep 21, 2019 - View & Read

1)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
2)
A parallel plate capacitor stores a charge Q at a voltage V. Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?
3)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
4)
A non-conducting charged ring carrying a charge of q, mass m and radius r is rotated about its axis with constant angular speed ω. Find the ratio of its magnetic moment with angular momentum is _____.
5)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is

12th Physics - Term 1 Five Mark Model Question Paper - by Question Bank Software - Sep 16, 2019 - View & Read

1)
When two objects are rubbed with each other, approximately a charge of 50 nC can be produced in each object. Calculate the number of electrons that must be transferred to produce this charge.
2)
Two electric bulbs marked 20 W – 220 V and 100 W – 220 V are connected in series to 440 V supply. Which bulb will get fused?
3)
What is the value of x when the Wheatstone’s network is balanced?
P = 500 Ω, Q = 800 Ω, R = x + 400, S = 1000 Ω
4)
A cell supplies a current of 0.9 A through a 2 Ω resistor and a current of 0.3 A through a 7 Ω resistor. Calculate the internal resistance of the cell.
5)
In a plane Electromagnetic wave, the electric field oscillates sinusoidally at a frequency of 1.5 x 10¹⁰Hz with & an amplitude of 36 Vm^-1.
(i) What is the wavelength of a wave?
(ii) What the amplitude of the oscillating magnetic field?
(iii) Straight the average energy density of the electric field \(\left( \overrightarrow { E } \right) \), is equal to average energy density of the magnetic field \(\left( \overrightarrow { B } \right) \)

12th Physics - Electromagnetic Waves Two Marks Questions - by Question Bank Software - Sep 16, 2019 - View & Read

1)
What is displacement current?
2)
What are electromagnetic waves?
3)
Write down the integral form of modified Ampere’s circuital law.
4)
Explain the concept of intensity of electromagnetic waves.
5)
What is meant by Fraunhofer lines?

12th Physics - Electromagnetic Induction and Alternating Current Two Marks Questions - by Question Bank Software - Sep 16, 2019 - View & Read

1)
How is Eddy current produced? How do they flow in a conductor?
2)
Mention the ways of producing induced emf.
3)
Give the principle of AC generator.
4)
List out the advantages of stationary armature-rotating field system of AC generator.
5)
What do you mean by resonant frequency?

12th Physics - Magnetism and Magnetic Effects of Electric Current Two Marks Questions - by Question Bank Software - Sep 16, 2019 - View & Read

1)
What is meant by magnetic induction?
2)
Define magnetic flux.
3)
What is magnetic susceptibility?
4)
State Biot-Savart’s law.
5)
What is meant by hysteresis?

12th Physics - Current Electricity Two Marks Questions - by Question Bank Software - Sep 16, 2019 - View & Read

1)
Write a short note on superconductors?
2)
What is electric power and electric energy?
3)
State Kirchhoff ’s voltage rule.
4)
State the principle of potentiometer.
5)
What is Peltier effect?

12th Physics Chapter 1 Electrostatics Two Marks Questions - by Question Bank Software - Sep 16, 2019 - View & Read

1)
What is meant by quantisation of charges?
2)
Write down Coulomb’s law in vector form and mention what each term represents.
3)
What is meant by ‘electric field lines’?
4)
The electric field lines never intersect. Justify.
5)
What is an equipotential surface?

12th Physics Quarterly Model Question Paper - by Question Bank Software - Sep 13, 2019 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
3)
An uncharged metal sphere is placed between two equal and oppositely charged metal plates. The nature of lines of force will be ______________
4)
The magnitude of electric dipole moment of water molecule is
5)
Which of the following statement on equipotential surface is wrong?

TN 12th Standard Physics Official Model Question Paper 2019 - 2020 - by Question Bank Software - Sep 10, 2019 - View & Read

12th Standard Physics - Electromagnetic waves Book Back Questions - by Question Bank Software - Sep 03, 2019 - View & Read

1)
What is displacement current?
2)
What are electromagnetic waves?
3)
What is meant by Fraunhofer lines?
4)
The relative magnetic permeability of the medium is 2.5 and the relative electrical permittivity of the medium is 2.25. Compute the refractive index of the medium.
5)
Discuss briefly the experiment conducted by Hertz to produce and detect electromagnetic spectrum.

12th Standard Physics - Magnetism and Magnetic Effects of Electric Current Book Back Questions - by Question Bank Software - Sep 02, 2019 - View & Read

1)
A particle having mass m and charge q accelerated through a potential difference V. Find the force experienced when it is kept under perpendicular magnetic field \(\vec { B } \).
2)
Three wires of equal lengths are bent in the form of loops. One of the loops is circle, another is a semi-circle and the third one is a square. They are placed in a uniform magnetic field and same electric current is passed through them. Which of the following loop configuration will experience greater torque?
3)
A non-conducting charged ring carrying a charge of q, mass m and radius r is rotated about its axis with constant angular speed ω. Find the ratio of its magnetic moment with angular momentum is _____.
4)
The vertical component of Earth’s magnetic field at a place is equal to the horizontal component. What is the value of angle of dip at this place?
5)
A simple pendulum with charged bob is oscillating with time period T and lets θ be the angular displacement. If the uniform magnetic field switched ON in a direction perpendicular to the plane of oscillation then ___________.

12th Standard Physics - Electromagnetic Induction and Alternating Current Book Back Questions - by Question Bank Software - Sep 02, 2019 - View & Read

1)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
2)
A circular coil with a cross-sectional area of 4 cm² has 10 turns. It is placed at the centre of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm². The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?
3)
An inductor 20 mH, a capacitor 50 μF and a resistor 40Ω are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is
4)
In an oscillating LC circuit, the maximum charge on the capacitor is Q. The charge on the capacitor when the energy is stored equally between the electric and magnetic fields is
5)
\(\frac{20}{\pi^2}H\) inductor is connected to a capacitor of capacitance C. The value of C in order to impart maximum power at 50 Hz is

12th Standard Physics Chapter 2 Current Electricity Book Back Questions - by Question Bank Software - Aug 31, 2019 - View & Read

1)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
2)
What is the value of resistance of the following resistor?
3)
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.
4)
The temperature coefficient of resistance of a wire is 0.00125 per °C. At 20°C, its resistance is 1 Ω. The resistance of the wire will be 2 Ω at ______.
5)
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of ______.

12th Standard Physics Unit 1 Electrostatics Book Back Questions - by Question Bank Software - Aug 30, 2019 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
3)
The total electric flux for the following closed surface which is kept inside water
4)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.
5)
Rank the electrostatic potential energies for the given system of charges in increasing order

12th Standard Physics Chapter 4 Electromagnetic Induction and Alternating Current One Mark Question with Answer Key - by Question Bank Software - Aug 29, 2019 - View & Read

1)
In a series resonant RLC circuit, the voltage across 100 Ω resistor is 40 V. The resonant frequency ω is 250 rad/s. If the value of C is 4 µF, then the voltage across L is
2)
An inductor 20 mH, a capacitor 50 μF and a resistor 40Ω are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is
3)
The instantaneous values of alternating current and voltage in a circuit are \(i=\frac { 1 }{ \sqrt { 2 } } \sin\left( 100\pi t \right) \) A and v \(=\frac { 1 }{ \sqrt { 2 } } \sin\left( 100\pi t+\frac { \pi }{ 3 } \right) V.\)The average power in watts consumed in the circuit is
4)
In an oscillating LC circuit, the maximum charge on the capacitor is Q. The charge on the capacitor when the energy is stored equally between the electric and magnetic fields is
5)
\(\frac{20}{\pi^2}H\) inductor is connected to a capacitor of capacitance C. The value of C in order to impart maximum power at 50 Hz is

12th Standard Physics Chapter 3 Magnetism and Magnetic Effects of Electric Current One Mark Question and Answer - by Question Bank Software - Aug 29, 2019 - View & Read

1)
The BH curve for a ferromagnetic material is shown in the figure. The material is placed inside a long solenoid which contains 1000 turns/cm. The current that should be passed in the solenoid to demagnetize the ferromagnet completely is _____.
2)
Two short bar magnets have magnetic moments 1.20 Am² and 1.00 Am² respectively. They are kept on a horizontal table parallel to each other with their north poles pointing towards south. They have a common magnetic equator and are separated by a distance of 20.0 cm. The value of the resultant horizontal magnetic induction at the mid-point O of the line joining their centres is (Horizontal components of Earth’s magnetic induction is 3.6 × 10^–5 Wb m^–2 )
3)
The vertical component of Earth’s magnetic field at a place is equal to the horizontal component. What is the value of angle of dip at this place?
4)
A flat dielectric disc of radius R carries an excess charge on its surface. The surface charge density is σ. The disc rotates about an axis perpendicular to its plane passing through the center with angular velocity ω. Find the magnitude of the torque on the disc if it is placed in a uniform magnetic field whose strength is B which is directed perpendicular to the axis of rotation.
5)
A simple pendulum with charged bob is oscillating with time period T and lets θ be the angular displacement. If the uniform magnetic field switched ON in a direction perpendicular to the plane of oscillation then ___________.

12th Standard Physics - Current Electricity One Mark Question and Answer - by Question Bank Software - Aug 28, 2019 - View & Read

1)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
2)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
3)
When 'n' resistors of equal resistance (R) are connected in series and in parallel respectively, then the ratio of their effective resistance is ______________
4)
Which of the following has negative temperature coefficient of resistance?
5)
The temperature co-efficient of resistance for alloys is _____________.

12th Standard Physics Unit 1 Electrostatics One Mark Question and Answer - by Question Bank Software - Aug 27, 2019 - View & Read

1)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
2)
The total electric flux for the following closed surface which is kept inside water
3)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
4)
The value of constant 'K' in coulomb law is _____________.

12th Standard Chapter 5 Electromagnetic Waves One Mark Question Paper with Answer - by Question Bank Software - Aug 27, 2019 - View & Read

1)
Consider an oscillator which has a charged particle oscillating about its mean position with a frequency of 300 MHz. The wavelength of electromagnetic waves produced by this oscillator is _____.
2)
The electric and the magnetic fields, associated with an electromagnetic wave, propagating along negative X axis can be represented by _____.
3)
In an electromagnetic wave traveling in free space the rms value of the electric field is 3 V m⁻¹. The peak value of the magnetic field is _____.
4)
Electromagnetic waves are produced by _____________.
5)
Which of the following electromagnetic waves has the highest frequency?

12th Standard Physics Chapter 4 Electromagnetic Induction and Alternating Current One Mark Question with Answer Key - by Question Bank Software - Aug 27, 2019 - View & Read

1)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
2)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
3)
A step-down transformer reduces the supply voltage from 220 V to 11 V and increase the current from 6 A to 100 A. Then its efficiency is
4)
In a series RL circuit, the resistance and inductive reactance are the same. Then the phase difference between the voltage and current in the circuit is
5)
An inductor 20 mH, a capacitor 50 μF and a resistor 40Ω are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is

12th Physics Unit 3 Magnetism and Magnetic Effects of Electric Current One Mark Question with Answer Key - by Question Bank Software - Aug 26, 2019 - View & Read

1)
A circular coil of radius 5 cm and 50 turns carries a current of 3 ampere. The magnetic dipole moment of the coil is nearly ____.
2)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.
3)
A wire of length l carrying a current I along the Y direction is kept in a magnetic field is given by \(\vec { B } =\frac { \beta }{ \sqrt { 3 } } =(\hat { i } +\hat { j } +\hat { k } )T.\) The magnitude of Lorentz force acting on the wire is _____.
4)
The vertical component of Earth’s magnetic field at a place is equal to the horizontal component. What is the value of angle of dip at this place?
5)
When current is doubled deflection is also doubled in ______________.

12th Physics Chapter 2 Current Electricity One Mark Question Paper - by Question Bank Software - Aug 24, 2019 - View & Read

1)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
2)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
3)
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.
4)
In Joule’s heating law, when R and t are constant, if the H is taken along the y axis and I² along the x axis, the graph is ______.
5)
Which of the following has negative temperature coefficient of resistance?

12th Physics Electrostatics One Mark Question Paper - by Question Bank Software - Aug 23, 2019 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
Which charge configuration produces a uniform electric field?
3)
If voltage applied on a capacitor is increased from V to 2V, choose the correct conclusion.
4)
Two metallic spheres of radii 1 cm and 3 cm are given charges of -1 \(\times\) 10^-2 C and 5 \(\times\) 10^-2 C respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is

12th Physics Quarterly Exam Model Two Marks Question Paper - by Question Bank Software - Aug 20, 2019 - View & Read

1)
What is meant by quantisation of charges?
2)
Give the relation between electric field and electric potential.
3)
Give a comparison of electrical and gravitional forces?
4)
The graph shows the variation of voltage 'v' across the plates of two capacitors A & B versus increase of charge 'Q' stored on them. Which of the two capacitors has higher capacitance?
Give reason.
5)
State microscopic form of Ohm’s law.

Plus Two Quarterly Exam Model One Mark Question Paper - by Question Bank Software - Aug 05, 2019 - View & Read

1)
Which charge configuration produces a uniform electric field?
2)
An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.
3)
Two points A and B are maintained at a potential of 7 V and -4 V respectively. The work done in moving 50 electrons from A to B is _______.
4)
The value of constant 'K' in coulomb law is _____________.

Plus 2 Physics Chapter 5 Electromagnetic Waves Model Question Paper - by Question Bank Software - Aug 03, 2019 - View & Read

1)
The dimension of \(\frac { 1 }{ { \mu }_{ 0 }{ \varepsilon }_{ 0 } } \) is _____.
2)
During the propagation of electromagnetic waves in a medium __________________.
3)
The EM waves do not transport _______________.
4)
Which EM waves are used in medicine to destroy cancer cells?
5)
A magnetic field is produced by ____________.

12th Standard Physics First Mid Term Model Question Paper - by Question Bank Software - Aug 01, 2019 - View & Read

1)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.
2)
The value of constant 'K' in coulomb law is _____________.
3)
For a large charge accumulation, the end of the conductor should have larger curvature that is_________.
4)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
5)
Three wires of equal lengths are bent in the form of loops. One of the loops is circle, another is a semi-circle and the third one is a square. They are placed in a uniform magnetic field and same electric current is passed through them. Which of the following loop configuration will experience greater torque?

11th Standard Physics Chapter 4 Electromagnetic Induction and Alternating Current Important Question Paper - by Question Bank Software - Jul 30, 2019 - View & Read

1)
The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t²− 50t + 250. The induced emf at t = 3s is
2)
When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is
3)
A circular coil with a cross-sectional area of 4 cm² has 10 turns. It is placed at the centre of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm². The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?
4)
In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is
5)
A step-down transformer reduces the supply voltage from 220 V to 11 V and increase the current from 6 A to 100 A. Then its efficiency is

12th Standard Physics Chapter 3 Magnetism and Magnetic Effects of Electric Current Important Question Paper - by Question Bank Software - Jul 26, 2019 - View & Read

1)
The magnetic field at the centre O of the following current loop is
2)
A circular coil of radius 5 cm and 50 turns carries a current of 3 ampere. The magnetic dipole moment of the coil is nearly ____.
3)
A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.
4)
Four wires each of length 2m are bent into four loops P, Q, R, and S, and then suspended into a uniform magnetic field as shown in the figure same current is passed in each loop. On which loop the couple will be the highest?
5)
A current carrying conductor is associated with _______________.

12th Physics Unit 2 Model Question Paper - by Question Bank Software - Jul 24, 2019 - View & Read

1)
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
2)
A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be ______.
3)
Two wires of A and B with circular cross section made up of the same material with equal lengths. Suppose R_A = 3 R_B, then what is the ratio of radius of wire A to that of B?
4)
A wire connected to a power supply of 230 V has power dissipation P₁. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is P₂. The ratio \(\frac{P_2}{P_1}\) is ______.
5)
When 'n' resistors of equal resistance (R) are connected in series and in parallel respectively, then the ratio of their effective resistance is ______________

12th Physics - Chapter 1 Electrostatics Important Question Paper - by Question Bank Software - Jul 18, 2019 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
3)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.
4)
The total electric flux for the following closed surface which is kept inside water
5)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.

12th Standard Physics Electrostatics Important Question Paper - by Ravikumar - Jul 18, 2019 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
The total electric flux for the following closed surface which is kept inside water
3)
The relative permittivity of water is _______.
4)
An isolated metal sphere of radius 'r' is given a charge' q'. The potential energy of the sphere is ____________

twelfth standard english medium important multiple choice questions in physics - by Ravikumar - Jun 27, 2019 - View & Read

1)
For sharper edge, the ______ is greater. This principle is used in Lightning arrestor
2)
For continuous charge distributions, _____ methods can be used.
3)
For a large charge accumulation, the end of the conductor should have larger curvature that is_________.
4)
Relative permittivity (ε_r) is also known as ________
5)
The energy stored per unit volume of space is defined as________.

frequently asked multiple choice questions twelfth standard english medium physics - by Ravikumar - Jun 27, 2019 - View & Read

1)
A charge Q is placed at the corner of a cube. The electric flux through all the six faces of the cube is
2)
Which graph shows the variation of electric field E due to a hollow spherical conductor of radius R as a function of distance from the centre of the sphere?
3)
In a hollow spherical shell potential (V) changes with respect to distance (r) from centre.
\(\left[ { V }_{ inside }=\frac { Q }{ 4\pi { \varepsilon }_{ 0 }R } r\le R,\quad { V }_{ outside }=\frac { Q }{ 4\pi { \varepsilon }_{ 0 }r } r\ge R,V\alpha \frac { 1 }{ r } \right] \)
4)
What physical quantities may X and Y represent? [Y represents the first mentioned quantity].
5)
During charging a capacitor variation of potential V of the capacitor with time t as shown a

Most important one mark questions physics chapter one - by Ravikumar - Jun 27, 2019 - View & Read

1)
If C is the capacitance of an air filled capacitor and C is the capacitance of dielectric filled capacitor, then
2)
The capacitance of a parallel plate capacitor increases from 5μf of 50μf when a dielectric is filled between the plates. The permitivity of the dielectric is
3)
An electric dipole placed at an angle in a nonuniform electric field experiences
4)
Two copper spheres A and B of same size are charged to same potential. A is hollow and B is solid. Which of the two holds more charge?
5)
A bird sitting an a high power line

Centum multiple choice questions Chepter one Physics - by Ravikumar - Jun 27, 2019 - View & Read

1)
The expression for the electric field due to a surface of total charge 'Q' is given by __________
2)
The dipole is called point dipole when the distance ______________
3)
The magnitude of torque on dipole is maximum if
4)
The magnitude of electric dipole moment of water molecule is
5)
The expression for electric potential difference is

New syllabus creative multiple choice questions physics - by Ravikumar - Jun 27, 2019 - View & Read

1)
The figure shows tow parallel equipotential surface A and B kept at a small distance 'r' a part from each other. A point change of Q coulomb is taken from the surface A to B. The amount of net work done will be
2)
The given figure is a plot of lines of force due to two charges q₁ & q₂ find out the sign of charges
3)
An uncharged metal sphere is placed between two equal and oppositely charged metal plates. The nature of lines of force will be ______________
4)
An isolated metal sphere of radius 'r' is given a charge' q'. The potential energy of the sphere is ____________
5)
In a hydrogen atom the electron revolves around the proton in an orbit of 0.53 \(\mathring { A } \). The potential produced by the electron on the nuleus is ___________

Physics chapter one new syllabus Important one mark questions - by Ravikumar - Jun 27, 2019 - View & Read

1)
Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?
2)
Which charge configuration produces a uniform electric field?
3)
An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
4)
Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.
5)
Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.

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