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प्रश्न
-
- the angle of refraction and
- the angle of deviation for the ray?
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उत्तर
The ray of light which is incident normally on a plane glass slab passes undeviated. That is such a ray suffers no bending at the surface because here the angle of incidence is 0°. Thus if angle of incidence ∠i= 0°, then the angle of refraction ∠r = 0°. And the angle of deviation of the ray will also be 0°.
संबंधित प्रश्न
Draw the diagram given below and clearly show the path taken by the emergent ray.

A ray of light passes from glass into air. The angle of refraction will be:
(a) equal to the angle of incidence
(b) greater than the angle of incidence
(c) smaller than the angle of incidence
(d) 45°
The highest refractive index is of ______.
The refractive index of glass is 1.5. From a point P inside a glass block, draw rays PA, PB and PC incident on the glass air surface at an angle of incidence 30°, 42° and 60° respectively.
- In the diagram show the approximate direction of these rays as they emerge out of the block.
- What is the angle of refraction for the ray PB?
`("Take" sin 42° =2/3)`
After tracing the path of rays of light through a glass slab for three different angles of incidence, a student measured the corresponding values angle of refraction r and angle of emergence e and recorded them in the table given below:
|
S. No. |
∠i |
∠i |
∠e |
|
I |
30° |
20° |
31° |
|
II |
40° |
25° |
40° |
|
III |
50° |
31° |
49° |
The correct observations are:
(A) I and II
(B) II and III
(C) I and III
(D) I, II and III
Fig. shows a ray of white light that passes through a prism and produces a spectrum.
(a) Name the phenomenon that is taking place.
(b) What colour would you see at X and Y?
(c) What radiation would you detect above X and below Y?

Write a relation between the angle of incidence (i), angle of emergence (e), angle of the prism (A), and angle of deviation (d) for a ray of light passing through an equilateral prism.
Draw ray of light bending towards the normal while passing from air to glass. Label your diagrams.
The diagram shows the path of a ray of light through a rectangular glass block placed in a liquid of uniform density.

(a) Does the light speed up or slow down in the glass,
(b) Give the reason for your answer.
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.
