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प्रश्न
Comment on the statement ‘The refractive index of glass is 3/2.’
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उत्तर
It means that the speed of light in glass is 2/3rd the speed of light in the air (or vacuum).
संबंधित प्रश्न
When rays of light are incident on a glass slab then the incident ray and emergent ray are _________ each other.
- perpendicular
- parallel
- opposite
- concurrent
Study the following four experimental set-ups I, II, III and IV for the experiment, "To trace the path of a ray of light through a rectangular glass slab."
Which of the marked set-ups is likely to give best results (P1 and P2 are the positions of pins fixed on the incident ray)?
(A) I
(B) II
(C) III
(D) IV
Why is the ratio of the velocities of light of wavelengths 4000Å and 8000Å in vacuum 1: 1?
When a ray of light from air enters a denser medium, it ______.
How is the angle of emergence related to the angle of incidence when prism is in the position of minimum deviation? Illustrate your answer with help of a labelled diagram using an equilateral prism?
The critical angle for glass-air is 45° for the light of yellow colour. State whether it will be less than, equal to, or more than 45° for (i) ref light, (ii) blue light?
The refractive index of air with respect to glass is expressed as `""_g μ_a=sin i /sin r`.
- Write down a similar expression for aμg in terms of the angles i and r.
- If angle r = 90°, what is the corresponding angle i called?
- What is the physical significance of the angle i in part (b)?
Why do the faces of persons sitting around campfire appear to shimmer?
Explain briefly what causes the twinkling of stars at night.
How does the angle of deviation produced by a prism depend on the colour of light used? Which colour of white light is deviated (i) most, (ii) least, by a prism?
