Wave Optics · Question 14

A beam of light consisting of wavelengths 650 nm and 550 nm illuminates the Young's double slits with separation of 2 mm such that the interference fringes are formed on a screen, placed at a distance of 1.2 m from the slits. The least distance of a point from the central maximum, where the bright fringes due to both the wavelengths coincide, is 10-5 m.

An unpolarised light is incident at an interface of two dielectric media having refractive indices of 2 (incident medium) and 2 3 (refracted medium) respectively. To satisfy the condition that reflected and refracted rays are perpendicular to each other, the angle of incidence is

1. 45
2. 60
3. 10
4. 30

In the Young's double slit experiment the intensity produced by each one of the individual slits is Io. The distance between two slits is 2 mm. The distance of screen from slits is 10 m. The wavelength of light is 6000 . The intensity of light on the screen in front of one of the slits is

1. Io2
2. Io
3. 2Io
4. 4Io

In two separate Young's double-slit experimental set-ups and two monochromatic light sources of different wavelengths are used to get fringes of equal width. The ratios of the slits separations and that of the wavelengths of light used are 2 : 1 and 1 : 2 respectively. The corresponding ratio of the distances between the slits and the respective screens (D1/D2) is .

When an unpolarized light falls at a particular angle on a glass plate (placed in air), it is observed that the reflected beam is linearly polarized. The angle of refracted beam with respect to the normal is . ( -1(1.52) = 57.7 , refractive indices of air and glass are 1.00 and 1.52, respectively.)

1. 36.3
2. 39.6
3. 42.6
4. 32.3

Which of the following are true for a single slit diffraction?

1. B, D only
2. A, D only
3. A, C, E only
4. B, C only

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.