### 12th Standard Physics Study material & Free Online Practice Tests - View Model Question Papers with Solutions for Class 12 Session 2019 - 2020 TN Stateboard [ Chapter , Marks , Book Back, Creative & Term Based Questions Papers - Syllabus, Study Materials, MCQ's Practice Tests etc..]

#### 12th Standard Physics Recent Developments in Physics English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 radiowaves 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 Sarojini - Tiruppur - View & Read

• 1)

Doping a semiconductor results in

• 2)

When a transistor is fully switched on, it is said to be

• 3)

Th e 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 semiconductoris ____________

• 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 Sarojini - Tiruppur - View & Read

• 1)

The barrier potential of a silicon diode is approximately

• 2)

The primary use of a zener diode is

• 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 Sarojini - Tiruppur - View & Read

• 1)

In a hydrogen atom, the electron revolving in the fourth orbit, has angular momentum equal to

• 2)

The electric potential between a proton and an electron is given by $V={ V }_{ 0 }in\left( \frac { r }{ { r }_{ 0 } } \right)$, where r0 is a constant. Assume that Bohr atom model is applicable of nth orbit rn 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 Sarojini - Tiruppur - View & Read

• 1)

Suppose an alpha particle accelerated by a potential of V volt is allowed to collide with a nucleus whose atomic number is Z, then the distance of closest approach of alpha particle to the nucleus is

• 2)

The ratio of the wavelengths for the transition from n=2 to n=1 in Li++, He+ and H is

• 3)

the nuclear radius of 27 al is 3.6 fermi, the approximate nuclear radius of 64Cu is

• 4)

A radioactive nucleus (initial mass number A and atomic number Z) emits 2α and 2 positrons. The ratio of number of neutrons to that of proton in the final nucleus will be

• 5)

A system consists of N0 nucleus at t=0. The number of nuclei remaining after half of a half-life (that is, at time t=$\frac{q}{2}T_\frac{1}{2}$)

#### 12th Standard Physics Dual Nature of Radiation and Matter English Medium Free Online Test One Mark questions with Answer Key 2020 - 2021 - by Sarojini - Tiruppur - 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 will be

• 3)

The mean wavelength of light from sun is taken to be 550 nm and its mean power is 3.8 × 1026W. The number of photons received by the human eye per second on the average from sunlight 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 metals which will emit photoelectrons for a radiation of wavelength 4100$\\ \\ \mathring { A } \\$ is/are

• 5)

The work function of a metal is hvo' 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 Sarojini - Tiruppur - View & Read

• 1)

The wavelength λe of an electron and λp of a photon of same energy E are related by

• 2)

A light source of wavelength 520 nm emits 1.04 × 1015 photons per second while the second source of 460 nm produces 1.38 × 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 Sarojini - Tiruppur - 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 1.0×10–5 cm is at 30o. 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 Sarojini - Tiruppur - 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 of f 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 a 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 Sarojini - Tiruppur - View & Read

• 1)

If the amplitude of the magnetic fi eld is 3 × 10−6 T, then amplitude of the electric fi eld for a electromagnetic waves is

• 2)

Th e electric and the magnetic field, associated with an electromagnetic wave, propagating along X axis can be represented by

• 3)

A radiation of energy E falls normally on a perfectly refl ecting 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 Sarojini - Tiruppur - View & Read

• 1)

The dimension of $\frac { 1 }{ { \mu }_{ 0 }{ \varepsilon }_{ 0 } }$ is

• 2)

Which of the following electromagnetic radiation 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)

Let E = Eo sin[106 x -ωt] be the electric field of 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 Sarojini - Tiruppur - 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. Th e 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 40 Ω 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 Sarojini - Tiruppur - 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)

Th e fl ux 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 Sarojini - Tiruppur - View & Read

• 1)

An electron moves straight inside a charged parallel plate capacitor of uniform charge density σ. Th e time taken by the electron to cross the parallel plate capacitor when the plates of the capacitor are kept under constant magnetic fi eld of induction $\vec { B }$is

• 2)

A wire of length l carries a current I along the Y direction and 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 of charge q, mass m and radius r is rotated 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 Sarojini - Tiruppur - View & Read

• 1)

The magnetic fi eld at the center O of the following current loop is

• 2)

Th e force experienced by a particle having mass m and charge q accelerated through a potential diff erence V when it is kept under perpendicular magnetic field $\vec { B }$ is

• 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 center of the spiral is

• 4)

A bar magnet of length l and magnetic moment 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 solenonid 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 Sarojini - Tiruppur - View & Read

• 1)

A wire of resistance 2 ohms per meter is bent to form a circle of radius 1m. Th e equivalent resistance between its two diametrically opposite points, A and B as shown in the fi gure is

• 2)

A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of diff erent colours for its identifi cation. Th e 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 300 K, 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 Sarojini - Tiruppur - View & Read

• 1)

Th e 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. Th e 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 40W, 5 bulbs of 100W, 5 fans of 80W and 1 heater of 1kW are connected. The voltage of electric mains is 220V. The minimum 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 Sarojini - Tiruppur - 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 fl ux through each Gaussian surface in increasing order.

• 3)

The total electric fl ux 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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. Th e equivalent resistance between its two diametrically opposite points, A and B as shown in the fi gure 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 Sarojini - Tiruppur - 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 diff erent colours for its identifi cation. Th e colour code sequence will be

• 5)

The equivalent resistance between A and Bin the figure is

#### 12th Standard Physics English Medium Free Online Test one mark questions with answer key 2020 - Part Nine - by Sarojini - Tiruppur - View & Read

• 1)

Two identical conducting balls having positive charges q1 and q2 are separated by a center to center 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 60W bulb for use in India is R, the resistance of a 60W bulb for use in USA will be

#### 12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Nine - by Sarojini - Tiruppur - View & Read

• 1)

An electric field $\vec { E } =10x\hat { i }$ exists in a certain region of space. Then the potential difference V = Vo – VA, where Vo is the potential at the origin and VA is the potential at x = 2 m is:

• 2)

In electrostatics if the charges are in motion, another force named __________ comes into play in addition to coulomb force

• 3)

Van de Graaff generator produces an electrostatic potential difference of_______ volts.

• 4)

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

• 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 Free Online Test one mark questions with answer key 2020 - Part Eight - by Sarojini - Tiruppur - 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 diff erent colours for its identifi cation. Th e 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - View & Read

• 1)

Two identical conducting balls having positive charges q1 and q2 are separated by a center to center 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 Eand A is

• 4)

Charge Q on a capacitor varies with voltage Vas 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Vas 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. Th e equivalent resistance between its two diametrically opposite points, A and B as shown in the fi gure 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 Sarojini - Tiruppur - View & Read

• 1)

An electric field $\vec { E } =10x\hat { i }$ exists in a certain region of space. Then the potential difference V = Vo – VA, where Vo is the potential at the origin and VA is the potential at x = 2 m is:

• 2)

Based on Franklin's convention amber rods are_________.

• 3)

The direction of electric field at a point the equatorial line due to an electric dipole is

• 4)

A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of diff erent colours for its identifi cation. Th e colour code sequence will be

• 5)

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 Sarojini - Tiruppur - View & Read

• 1)

An electric dipole is placed at an alignment angle of 300 with an electric fi eld of 2 × 105 NC-1. It experiences a torque equal to 8 N m. Th e 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 potentid 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 out of the battery?

#### 12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Five - by Sarojini - Tiruppur - 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 60W bulb for use in India is R, the resistance of a 60W 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 Sarojini - Tiruppur - 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 the 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 centers is (Horizontal components of Earth’s magnetic induction is 3.6 x 10-5 Wb m-2 )

#### 12th Standard Physics English Medium Free Online Test 1 mark questions 2020 - Part Four - by Sarojini - Tiruppur - 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 εr = 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 Sarojini - Tiruppur - View & Read

• 1)

An electric field $\vec { E } =10x\hat { i }$ exists in a certain region of space. Then the potential difference V = Vo – VA, where Vo is the potential at the origin and VA 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 QμC 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 Sarojini - Tiruppur - View & Read

• 1)

Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric fl ux 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 RA = 3 RB, 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 Sarojini - Tiruppur - 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 60W bulb for use in India is R, the resistance of a 60W bulb for use in USA will be

• 3)

A non-conducting charged ring of charge q, mass m and radius r is rotated with constant angular speed ω. Find the ratio of its magnetic moment with angular momentum is

• 4)

Th e current i fl owing in a coil varies with time as shown in the fi gure. Th e variation of induced emf with time would be

• 5)

Consider an oscillator which has a charged particle and oscillates about its mean position with a frequency of 300 MHz. Th e 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 Sarojini - Tiruppur - View & Read

• 1)

The total electric fl ux for the following closed surface which is kept inside water

• 2)

Th e 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 center of the spiral is

• 4)

Th e fl ux 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 and oscillates about its mean position with a frequency of 300 MHz. Th e 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 Sarojini - Tiruppur - 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 the 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 centers is (Horizontal components of Earth’s magnetic induction is 3.6 x 10-5 Wb m-2 )

• 3)

An inductor 20 mH, a capacitor 50 μF and a resistor 40 Ω 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 60o. 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 position 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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)

Direction of magnetic force on a positive charge moving in a magnetic field is given by

• 5)

Electric filament lamp gives rise to

#### 12th Standard Physics English Medium Free Online Test Creative One Mark questions with Answer Key - Part Three - by Sarojini - Tiruppur - 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 corrent 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 Sarojini - Tiruppur - 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 X-axis and magnetic field is in y-axis then the wire experiences

• 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - View & Read

• 1)

When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index,

• 2)

When light is incident on a soap film of thickness 5×10–5 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 than the number of images will be

• 4)

A ray of light is incidenting normally on a .plane mirror. The angle of reflection will be

• 5)

A point object 0 is placed between two plane mirrors as shown is 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 Sarojini - Tiruppur - View & Read

• 1)

The total electric fl ux 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 Sarojini - Tiruppur - 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 45o. 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 Sarojini - Tiruppur - View & Read

• 1)

The total electric fl ux 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - View & Read

• 1)

Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric fl ux 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 = Vo – VA, where Vo is the potential at the origin and VA 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. Th e equivalent resistance between its two diametrically opposite points, A and B as shown in the fi gure is

• 5)

In a large building, there are 15 bulbs of 40W, 5 bulbs of 100W, 5 fans of 80W and 1 heater of 1kW are connected. The voltage of electric mains is 220V. The minimum capacity of the main fuse of the building will be

#### 12th Standard Physics English Medium Free Online Test Book Back one Mark questions - by Sarojini - Tiruppur - 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 x 10-2 C and 5 x 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 diff erent colours for its identifi cation. Th e 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 RA = 3 RB, 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 Sarojini - Tiruppur - View & Read

• 1)

An electric field $\vec { E } =10x\hat { i }$ exists in a certain region of space. Then the potential difference V = Vo – VA, where Vo is the potential at the origin and VA 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 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - View & Read

• 1)

Two identical conducting balls having positive charges q1 and q2 are separated by a center to center 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. Th e 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 600. Suppose 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 vo 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 Sarojini - Tiruppur - 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 capcicitor

• 4)

Explain the variation of resistivity of conductor and semiconductor with change in temperature

• 5)

Two metallic wires PI &P2 of the same material & same length but different cross sectional areas Al & 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 Sarojini - Tiruppur - View & Read

• 1)

Four charges are arranged at the corners of the square PQRS of side a 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 εo = 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 be fused?

#### 12th Physics English Medium Important 5 Mark Creative Questions (New Syllabus 2020) - by Sarojini - Tiruppur - 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 25cm. 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 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 Sarojini - Tiruppur - View & Read

• 1)

A water molecule has an electric dipole moment of 6.3 × 10-30 Cm. A sample contains 1022 water molecules, with all the dipole moments aligned parallel to the external electric field of magnitude 3 × 105 NC-1. How much work is required to rotate all the water molecules from θ = 00 to 900?

• 2)

A parallel plate capacitor filled with mica having εr = 5 is connected to a 10 V battery. The area of the parallel plate is 6 m2 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 × 10-11 m. The magnitude of charges on the electron and proton are 1.6 × 10-19 C. Mass of the electron is me = 9.1 × 10-31 kg and mass of proton is mp = 1.6 × 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 in the region perpendicular to the direction of both $\vec { B }$ & $\vec { E }$ and moves undeflected. Find the velocity of electron.

#### 12th Standard Physics English Medium Important 3 Mark Book Back Questions (New Syllabus) 2020 - by Sarojini - Tiruppur - View & Read

• 1)

Calculate the number of electrons in one coulomb of negative charge.

• 2)

A block of mass m and 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - View & Read

• 1)

What is mean 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 Sarojini - Tiruppur - 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 180o.

• 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)

Aparallel 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?
Qo - charge; Vo - potential difference,
Co - capacitance, Eo- electric field.
U0 - energy spred, 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - View & Read

• 1)

What are induced dipoles.

• 2)

Asphere of charge +Q is fixed. Asmaller 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)

Aparallel 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?
Qo - charge; Vo - potential difference,
Co - capacitance, Eo- electric field.
U0 - energy spred, 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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)

Th ree 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. Th ey are placed in a uniform magnetic fi eld and same electric current is passed through them. Which of the following loop confi guration will experience greater torque ?

• 4)

A simple pendulum with charged bob is oscillating with time period T and let θ be the angular displacement. If the uniform magnetic field i 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 center of the spiral is

• 5)

A non-conducting charged ring of charge q, mass m and radius r is rotated 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 Sarojini - Tiruppur - 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 Sarojini - Tiruppur - 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 center to center 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. Th e power is

• 4)

What is the value of resistance of the following resistor?

• 5)

In a large building, there are 15 bulbs of 40W, 5 bulbs of 100W, 5 fans of 80W and 1 heater of 1kW are connected. The voltage of electric mains is 220V. The minimum capacity of the main fuse of the building will be

#### 12th standard Physics full portion important One Mark Questions - 2020 - by Sarojini - Tiruppur - View & Read

• 1)

The total electric fl ux 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)

Th e 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 - 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)

• 5)

Why steel is preferred in making Robots?

#### 12th Physics Communication Systems - Two Marks Study Materials - by 8682895000 - 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)

• 5)

What do you mean by Internet of Things?

#### 12th Physics Semiconductor Electronics - Two Marks Study Materials - by 8682895000 - 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 - View & Read

• 1)

What are cathode rays?

• 2)

Write down the postulates of Bohr atom model.

• 3)

What is distance of dosest approach?

• 4)

Define atomic mass unit u.

• 5)

What is binding energy of a nucleus? Give it expression.

#### 12th Physics Dual Nature of Radiation and Matter - Two Marks Study Materials - by 8682895000 - 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 - View & Read

• 1)

Explain the working of an endoscope.

• 2)

Arrive at lens equation from lens maker's formula.

• 3)

Write a short note on quantum theory of light.

• 4)

What is a wavefront?

• 5)

How does wavefront division provide coherent sources?

#### 12th Physics Electromagnetic Waves - Two Marks Study Materials - by 8682895000 - 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 - 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 - 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 - 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 - 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 mean by ‘Electric field lines’?

• 4)

Define ‘electrostatic potential”.

• 5)

What is dielectric strength?

#### 12th Physics - Full Portion Five Marks Questions - by 8682895000 - 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 εr = 5 is connected to a 10 V battery. The area of the parallel plate is 6 m2 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 ACE and ABC. Apply Kirchoff’s voltage rule.

• 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 - 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 (εr = 80)

• 2)

Consider four equal charges q1,q2, q3 and q4 = q = +1μC 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 -9μC find the electrostatic potentials at points P and Q.

(c) Calculate the work done to bring a test charge +2μC from infinity to the point P. Assume the charge +9μC is held fixed at origin and +2μC 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 IAB 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 IAB.

### TN Stateboard Education Study Materials

The His

#### 12th Stateboard Physics 2019 - 2020 Academic Monthly Syllabus - by Sarojini - Tiruppur Aug 02, 2019 Aug 02, 2019

Physics 2019 - 2020 Academic Monthly Syllabus

### TN Stateboard Updated Class 12th Physics Syllabus

#### Electrostatics

Introduction - Coulomb's Law - Electric Field and Electric Field Lines - Electric dipole and Its Properties - Electrostatic Potential and Potential Energy - Gauss Law and Its Applications - Electrostatics of Conductors and Dielectrics - Capacitors and Capacitance - Distribution of Charges In A Conductor and Action At Points

#### Current Electricity

Introduction - Electric Current - Ohm’s Law - Energy and Power In Electrical Circuits - Electric Cells and Batteries - Kirchhoff ’s Law - Heating Effect of Electric Current - Thermoelectric Current

#### Magnetism and magnetic effects of electric current

Introduction of Magnetism - Coulomb's Inverse Square Law of Magnetism - Torque Acting On a Bar Magnet In Uniform Magnetic Field - Magnetic Properties - Classification of Magnetic Materials - Hysteresis - Magnetic Effects of Current - Biot - Savart Law - Ampere’s Circuital Law - Lorentz Force - Torque On a Current Loop

#### Electromagnetic Induction And Alternating Current

Introduction - Electromagnetic Induction - Eddy currents - Self-Induction - Methods of Producing Induced EMF - AC Generator - Transformer - Alternating Current - Power
In AC Circuits - Oscillations In LC Circuits

#### Electromagnetic waves

Introduction - Electromagnetic Waves - Types of Spectrum-Emission and Absorption Spectrum-Fraunhofer Lines

#### TN StateboardStudy Material - Sample Question Papers with Solutions for Class 12 Session 2019 - 2020

Latest Sample Question Papers & Study Material for class 12 session 2019 - 2020 for Subjects Maths, Chemistry, Biology, Computer Science, Business Maths, Economics, Commerce, Accountancy, History, Computer Applications, Computer Technology in PDF form to free download [ available question papers ] for practice. Download QB365 Free Mobile app & get practice question papers.

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