Wave Optics · Question 1

In interference and diffraction, the light energy is redistributed. If it reduces in one region, producing a dark fringe, it increases in another region, producing a bright fringe. Choose the correct answer from the options given below :

1. A is false, but B is true
2. A is true, but B is false
3. A is true and B is also true
4. Both A and B are false

The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at 22.5 from the polarization axis of one of the polaroids, is (I0 is the intensity of polarised light after passing through the first polaroid):

1. I08
2. I016
3. I02
4. I04

An unpolarized light beam travelling in air is incident on a medium of refractive index 1.73 at Brewster's angle. Then

1. Both reflected and transmitted light are perfectly polarized with angles of reflection and refraction close to 60 and 30 , respectively
2. Transmitted light is completely polarized with angle of refraction close to 30
3. Reflected light is completely polarized and the angle of reflection is close to 60
4. Reflected light is partially polarized and the angle of reflection is close to 30

If the monochromatic source in Young's double slit experiment is replaced by white light, then

1. Interference pattern will disappear
2. There will be a central dark fringe surrounded by a few coloured fringes
3. There will be a central bright white fringe surrounded by a few coloured fringes
4. All bright fringes will be of equal width

An unpolarised light beam strikes a glass surface at Brewster's angle. Then

1. The reflected light will be partially polarised.
2. The refracted light will be completely polarised.
3. Both the reflected and refracted light will be completely polarised.
4. The reflected light will be completely polarised but the refracted light will be partially polarised.

Two slits in Young's double slit experiment are 1.5 mm apart and the screen is placed at a distance of 1 m from the slits. If the wavelength of light used is 600 10-9 m then the fringe separation is

1. 4 10-5 m
2. 9 10-8 m
3. 4 10-7 m
4. 4 10-4 m

Interference pattern can be observed due to superposition of the following waves: Choose the correct answer from the options given below.

1. B and C
2. B and D
3. A and C
4. A and B

A beam of unpolarized light of intensity I0 is passed through a polaroid A, then through another polaroid B, oriented at 60 and finally through another polaroid C, oriented at 45 relative to B as shown. The intensity of emergent light is: [figure]

1. I016
2. I04
3. I02
4. I032

For Young's double slit experiment, two statements are given below : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are false
2. Statement I is true but Statement II is false
3. Statement I is false but Statement II is true
4. Both Statement I and Statement II are true

In a Young's double slit experiment, a student observes 8 fringes in a certain segment of screen when a monochromatic light of 600 nm wavelength is used. If the wavelength of light is changed to 400 nm, then the number of fringes he would observe in the same region of the screen is

1. 6
2. 8
3. 9
4. 12