One requires 11 \(eV\) of energy to dissociate a carbon monoxide molecule into carbon and oxygen atom. The minimum frequency of the appropriate electromagnetic radiation to achieve the dissociation lines in

A linearly polarized electromagnetic wave given as \(E={ E }_{ 0 }\overset { \wedge }{ i } cos \ (kz-wt)\) incident wall at \(z=a\) . Assuming that the material of the wall os optically inactive, the reflected wave will be given as

Light with an energy flux of \(​​20 \ W/cm^{ 2 }\) falls on a non-reflecting surface at normal incidence. If the surface has an area of \(30 cm^{ 2 }\), the total momentum delivered (for complete absorption) during \(30\) minutes is:

The electric field intensity produced by the radiations coming from 100 W bulb at a 3m distance is E. The electric field intensity produced by the radiations coming from 50w bulb at the same distance is:  

In an electromagnetic wave, the electric and magnetic fields are 100 V/m and 0.265 A/m. The maximum energy flow per second per unit area will be 

Electromagnetic waves travel in a medium which has relative permeability 1.3 and relative permittivity 2.14. The speed of electromagnetic wave in the medium will be

A small metallic ball is charged positively and negatively in a sinusoidal manner at a frequency of \({ 10 }^{ 6 } \ cps\) . The maximum charge on the ball is \({ 10 }^{ -6 } \ C\). what is the displacement current due to the alternating current?

A flood light is covered with a filter that transmits red light. The electric field of the emerging beam is represented by a sinusoidal wave.
\({ E }_{ x }=36 \ sin\quad (1.20\times { 10 }^{ 7 }z=3.6\times { 10 }^{ 15 }t) \ V/m\)
the average intensity of the beam is watt/\({ (metre) }^{ 2 }\) will be:

The sun delivers of electromagnetic\({ 10 }^{ 3 } \ W/{ m }^{ 2 }\) flux to the earth surface. The total power that is incident on a roof of dimension 8 m\(\times \) 20 m, will be

Following Q.19, the radiation force on the roof will be

A plane electromagnetic wave travels in vacuum along the z-direction. what can you say about the direction of an electric and magnetic field vectors

Write the formula for the velocity of light in a material medium of relative permeability \({ \epsilon }_{ r }\) and relative magnetic permeability  \({ \mu }_{ r }\)

What are the basic sources of an electromagnetic wave?

Which part of electromagnetic spectrum is absorbed from sunlight by ozone layer?

A mirror is turned through\(15°\). Through what angle will the reflected ray turn?

What is the least distance of distinct vision for a normal eye? Is it the same as the distance of near point?

A and B are two point on water surface where waves are generated. What is the phase different
(i) A and B are on same wave front separated by distance \(\lambda\).
(ii) a and B are on successive crests separated by distance 2\(\lambda\).
(iii) A and B are on successive troughs separated by distance 3\(\lambda\).

How does the fringe width in Young's double slit experiment change when the distance of separation between the slits and screen is doubled?

In Young's double experiment the intensity of central maxima is I. What will be the intensity at the same place, if one slit is closed?

How will the photoelectric current change on decreasing the wavelength of incident radiation for a given photosensitive material?

The stopping potential in an experiment on a photoelectric effect is 1.5V. What is the maximum kinetic energy of the photoelectrons emitted?

In a plane electromagnetic wave, the electric field varies with time having an amplitude. \(1 \ V{ m }^{ -1 }\) The frequency of a wave is \(0.5\times { 10 }^{ 15 }Hz.\) The wave is propagating along Z-axis. what is the average energy density of 
(i) electric field
(ii) magnetic field
(iii) total
(iv) what is the amplitude of magnetic field?

Why does galvanometer show a momentary deflection at the time of charging or discharging a capacitor? Write the necessary expression to explain this observation?

A parallel plate capacitor with plate area A and plate separation d is charged by a steady current I. Let a plane surface of area A/3 parallel to the plates and situated symmetrically between the plates. what is the displacement current through this area?

How are the magnitudes of the electric and magnetic fields related to the velocity of the EM wave?

(a) How are electromagnetic waves produced?
(b) How do you convince yourself that electromagnetic waves carry energy and mimentum?

Consider figure for photoemission. How would you reconcile with momentum conservation? Note light (photons) have momentum in a different direction than the emitted electrons.

The two lines marked A and B in the given figure. Show a plot of de-Broglie wavelength \(\lambda \) versus \(\frac { 1 }{ \sqrt { V } } \), where V is the accelerating potential for two nuclei  \(_{ 1 }^{ 2 }{ H }\) and \(_{ 1 }^{ 3 }{ H }\).
(i) What does the slope of the lines represent?
(ii) Identify, which of the lines corresponded to these nuclei.

The Kinetic Energy (K.E.), of a beam of electrons, accelerated through a potential V, equals the energy of a photon of wavelength 5460 nm. Find the de Broglie wavelength associated with this beam of electrons.

Magnetic field lines can be neither emanate from a point nor end on a point. Yet the field lines outside a bar magnet do seem to start from the North pole and end on the South pole. Does the second fact contradict the first? Explain.

Identify the type of waves which are produced by the following way and write one application for each:
(i) Radioactive decay of the nucleus.
(ii) Rapid acceleration and decelerations of electrons in aerials.
(iii) Bombarding a metal target by high energy electrons.

Calculate the time which light will take to travel normally through a glass plate of thickness 1 mm. Refractive index of glass is 1.5.

A jar of height is filled with a transparent liquid of refractive index \(\mu \)(figure). At the centre of the jar on the bottom surface is a dot. Find the minimum diameter of a disc, such that when placed on the top surface symmetrically about the centre, the dot is invisible.

The problem is based on the principle of total inter reflection and area of visibility.

When a plane wave front, of light, of wavelength I, is incident on a narrow slit, an intensity distribution pattern, of the form shown is observed on a screen, suitable kept behind the slit. Name the phenomenon observed.

(i) Obtain the conditions for the formation of central maximum and secondary maxima and the minima.
(ii) Why is there significant fall in intensity of the secondary maxima compared to the central maximum, where as in double slit experiment all the bright fringes are of the same intensity?
(iii) When the width of the slit is made double the original width, how is the size of the central band affected?

An electron and photon each have a wavelength 1.00nm Find
(i) their moment
(ii) the energy of the photon and
(iii) the kinetic energy of electron.

An electron and a photon each have a wavelength 2nm. Find (i) their momenta (ii) the energy of a photon and (iii) the kinetic energy of electron. \(Given\ h=6.6\times { 10 }^{ -34 }Js\)

When a surface is irradiated with light of wavelength \(4950\mathring { A, } \)a photocurrent appears which vanishes if a retarding potential greater than 0.6 volts is applied across the photo-tube. When a different source of light is used, it is found that the critical retarding potential is changed to 1.1volt. Find the work function of the emitting surface and the wavelength of the second source. If the photoelectrons are subjected to a magnetic field of 10 teslas, what changes will be observed in the above two retarding potentials?

(a) A point object is placed in front of a double convex lens (of refractive index n =n₂/n₁ with respect air) with its spherical faces of radii of curvature R₁ and R_2.. Show the path of rays due to surface to obtain the formation of the real image of the object.
Hence obtain the lens maker's formula for a thin lens.
(b) A double convex lens having both faces of the same radius of curvature has refractive index 1.55. Find out the radius of curvature of the lens required to get the focal length of 20 cm.

Em waves have a wide range of wavelength starting from \({ 10 }^{ -14 }\)m to \({ 10 }^{ 3 }\) m. The em waves of different wavelength are used for different purpose. The gamma rays which have the lowest wavelength are most energetic em waves and radio waves which have the largest wavelength are least energetic.
Read the above passage and answer the following question
(i) What are more energetic waves, x-rays or ultraviolet rays?
(ii) Why are the radio waves not used to detect fracture in the bones of the human body when they can deliver a message at large distance?
(iii) What are the basic values displayed by above study

If light passes near a massive object, the gravitational interaction causes a bending of the ray. This can be thought of as happening due to a change in the effective refractive index of the medium given by
\(n(r)=\frac { 1+2GM }{ { rc }^{ 2 } } \)
where r is the distance of the point of consideration from the centre of the mass of the massive body. G is the universal gravitational constant, M the mass of the body and c the speed of light in vacuum. considering a spherical object find the deviation of the ray from the original path as it grazes the object

The magnifying power of an astronomical telescope in the normal adjustment position is 100. The distance between the objective and eye piece is 101 cm. Calculate the focal lengths of objective and eye piece.

An angular magnification (mafnifying power) of 30 is desired using an objective of focal length 1.25cm and an eyepiece of focal length 5cm. How will you set up the compound microscope?

A child is observing a thin film such as a layer of oil on water showing beautiful colours, when illuminated by white light. He feels happy and surprised to see this.His teacher explains him example of spreading of kerosene oil on water to prevent malaria and dengue.
Read the above passage and answer the following questions:
(i) What values are displayed by his teacher?
(ii) Name the phenomenon involved.