Wave Optics · Question 20

In a double slit experiment the distance between the slits is 0.1 cm and the screen is placed at 50 cm from the slits plane. When one slit is covered with a transparent sheet having thickness t and refractive index n (= 1.5), the central fringe shifts by 0.2 cm. The value of t is cm.

1. 6.0 10-3
2. 8 10-4
3. 5.0 10-3
4. 5.6 10-4

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are true
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 false

In a Young's double slit experiment set up, the two slits are kept 0.4 mm apart and screen is placed at 1 m from slits. If a thin transparent sheet of thickness 20 is introduced in front of one of the slits then center bright fringe shifts by 20 mm on the screen. The refractive index of transparent sheet is given by 10, where is .

In a Young's double slit experiment, the source is white light. One of the slits is covered by red filter and another by a green filter. In this case:

1. there shall be alternate interference fringes of red and green.
2. there shall be an interference pattern for red distinct from that for green.
3. there shall be an interference pattern, where each fringe's pattern center is green and outer edges is red.
4. there shall be no interference fringes.

Two plane polarized light waves combine at a certain point whose electric field components are E1 = E0 t E2 = E0 ( t + 3 ) Find the amplitude of the resultant wave.

1. 1.7 E0
2. E0
3. 0.9 E0
4. 3.4 E0

In a Young's double slit experiment, the slits are separated by 0.2 mm. If the slits separation is increased to 0.4 mm, the percentage change of the fringe width is :

1. 25\%
2. 50\%
3. 0\%
4. 100\%

Two polarisers P1 and P2 are placed in such a way that the intensity of the transmitted light will be zero. A third polariser P3 is inserted in between P1 and P2, at particular angle between P2 and P3. The transmitted intensity of the light passing through all three polarisers is maximum. The angle between the polarisers P2 and P3 is :

1. /6
2. 3
3. 4
4. /8

In a Young's double slit experiment, two slits are located 1.5 mm apart. The distance of screen from slits is 2 m and the wavelength of the source is 400 nm. If the 20 maxima of the double slit pattern are contained within the central maximum of the single slit diffraction pattern, then the width of each slit is x 10-3 cm, where x-value is .

Two coherent monochromatic light beams of intensities 4I and 9I are superimposed. The difference between the maximum and minimum intensities in the resulting interference pattern is xI. The value of x is .

Two monochromatic light beams have intensities in the ratio 1:9. An interference pattern is obtained by these beams. The ratio of the intensities of maximum to minimum is

1. 8 : 1
2. 4 : 1
3. 3 : 1
4. 9 : 1