Unpolarised light is incident from the air on a plane surface of a material of refractive index 'μ'. At a particular angle of incidence 'i', it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation?
1. | the reflected light is polarised with its electric vector parallel to the plane of incidence. |
2. | the reflected light is polarised with its electric vector perpendicular to the plane of incidence. |
3. | |
4. |
In Young's double-slit experiment, the separation d between the slits is 2 mm, the wavelength of the light used is 5896 Å and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0.20°. To increase the fringe angular width to 0.21° (with same and D) the separation between the slits needs to be changed to:-
1. 1.8 mm
2. 1.9 mm
3. 2.1 mm
3. 1.7 mm
Two polaroids P1 and P2 are placed with their axis perpendicular to each other. Unpolarised light of intensity \(I_0\) is incident on P1. A third polaroid P3 is kept in between P1 and P2 such that its axis makes an angle \(45^\circ\) with that of P1. The intensity of transmitted light through P2 is:
1.
2.
3.
4.
An interference pattern is obtained with two coherent light sources of intensity ratio \(n.\) In the interference pattern, the ratio will be:
1.
2.
3.
4.
A linear aperture whose width is 0.02 cm is placed immediately in front of a lens of focal length 60 cm. The aperture is illuminated normally by a parallel beam of wavelength 5 x 10-5 cm. The distance of the first dark band of the diffraction pattern from the centre of the screen is:
1. 0.10 cm
2. 0.25 cm
3. 0.20 cm
4. 0.15 cm
The intensity at the maximum in Young's double-slit experiment is Io. The distance between the two slits is d = 5, where is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance D = 10d?
1.
2.
3.
4.
In a diffraction pattern due to a single slit of width a, the first minimum is observed at an angle of 30o when the light of wavelength 5000 Å is incident on the slit. The first secondary maximum is observed at an angle of: