A beam of light is converging towards a point on a screen. A plane glass plate whose thickness in the direction of the beam = , refractive index = , is introduced in the path of the beam. The convergence point is shifted by ____.
The length of the optical path of two media in contact of length and of refractive indices and respectively, is ____.
On heating a liquid, the refractive index generally ____.
decreases
increases or decreases depending on the rate of heating
does not change
increases
If denotes a unit vector along incident light ray, a unit vector along refracted ray into a medium of refractive index and unit vector normal to boundary of medium directed towards incident medium, then law of refraction is ____.
The ratio of thickness of plates of two transparent mediums A and B is 6: 4. If light takes equal time in passing through them, then refractive index of B with respect to A is ____.
1.4
1.5
1.75
1.33
An under water swimmer is at a depth of 12 m below the surface of water. A bird is at a height of 18 m from the surface of water, directly above his eyes. For the swimmer the bird appears to be at a distance from the surface of water equal to (Refractive Index of water is 4/3) ____.
24 m
12 m
18 m
9 m
The optical path of a monochromatic light is same if it goes through 4.0 cm of glass or 4.5 cm of water. If the refractive index of glass is 1.53, the refractive index of the water is ____.
1.30
1.36
1.42
1.46
The wavelength of sodium light in air is 5890 Å. The velocity of light in air is The wavelength of light in a glass of refractive index 1.6 would be close to ____.
5890 Å
3681 Å
9424 Å
15078 Å
A glass slab of thickness 3 cm and refractive index 3/2 is placed on ink mark on a piece of paper. For a person looking at the mark at a distance 5.0 cm above it, the distance of the mark will appear to be ____.
3.0 cm
4.0 cm
4.5 cm
5.0 cm
A diver in a swimming pool wants to signal his distress to a person lying on the edge of the pool by flashing his water proof flash light ____.
he must direct the beam vertically upwards
he has to direct the beam horizontally
he has to direct the beam at an angle to the vertical which is slightly less than the critical angle of incidence for total internal reflection
he has to direct the beam at an angle to the vertical which is slightly more than the critical angle of incidence for the total internal reflection
Finger prints on a piece of paper may be detected by sprinkling fluorescent powder on the paper and then looking it into ____.
mercury light
sunlight
infrared light
ultraviolet light