CBSE
Multiple Choice QuestionsWhen the angle of incidence is 60° on the surface of a glass slab, it is found that the reflected ray is completely polarised. The velocity of light in glass is
√2 x 108 ms-1
√3 x 108 ms-1
2 x 108 ms-1
3 x 108 ms-1
In Young's double-slit experiment with sodium vapor lamp of wavelength 589 nm and the slits 0.589 min apart, the half angular width of the central maximum is
sin-1(0.01)
sin-1(0.0001)
sin-1(0.001)
sin-1(0.1)
The specific rotation of a sugar solution is 0.5 deg m2/kg. 200 kg-m-3 of impure sugar solution is- taken in a sample polarimeter tube of length 20 cm and optical rotation is found to be 19°. The percentage of purity of sugar is
20%
80%
95%
89%
Two coherent monochromatic light beams of intensities I and 4 I superimpose. The maximum and minimum possible intensities in the resulting beam are respectively
5I and I
5I and 3I
3I and I
9I and I
The wavefront of a wave has direction with wave motion
parallel
perpendicular
opposite
at an angle of θ
A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of the central bright fringe is
1.2 cm
1.2 mm
2.4 cm
2.4 mm
A wavefront is represented by the plane y = 3-x. The propagation of the wave takes place at
45° with x direction
135° with x direction
60° with x direction
No sufficient data
Four independent waves are expressed as
(i) and (iii)
(i) and (iv)
(ii) and (iv)
not possible at all
The intensity ratio of two coherent sources of light is P. They are interfering in the same region and produce an interference pattern. Then the fringe visibility is
The intensity of sound gets reduced by 10% on passing through a slab. The reduction in intensity on passing through two consecutive slabs would be
20 %
19 %
5 %
50 %
