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प्रश्न
The speed of light in air is 3 × 108 ms-1. Calculate the speed of light in water. The refractive index of water is 4/3.
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उत्तर
The refractive index of water `="Speed of light in air"/"Speed of light in water"`
∴ Speed of light in water `="Speed of light in air"/"Refractive index of water"`
= `(3xx10^8)/(4//3)`
= 2.25 × 108 ms−1.
संबंधित प्रश्न
Explain how the formation of a rainbow occurs.
Four students P, Q, R and S traced the path of a ray of light passing through a glass slab for an angle of incidence 40° and measured the angle of refraction. The values as measured them were 18°; 22°; 25° and 30° respectively. The student who has performed the experiment methodically is
(A) P
(B) Q
(C) R
(D) S
Which colour of light travels fastest in any medium except air?
Observe the following figure and answer the questions given under it:

1) How many times does refraction take place in the above figure?
2) What happens to the ray of light when it passes from air to glass?
3) What happens to the ray of light when it passes from glass to air?
4) What are the rays AB and CD in the figure called?
5) Define refraction.
How is the reflection of light ray from a plane mirror different from the refraction of light ray as it enters a block of glass?
Name the colour of white light which is deviated the most on passing through a prism.
Fig 4.31 below shows a light ray of single colour incident normally on two prisms A and B. In each case draw the path of the ray of light as it enters and emerges out of the prism. Mark the angle wherever necessary.
In the diagram below, PQ is a ray of light incident on a rectangular glass block.

Copy the diagram and complete the path of the ray of light through the glass block. In your diagram, mark the angle of incidence by letter ‘i’ and the angle of emergence by the letter ‘e’.
