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प्रश्न
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.
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उत्तर
(a) The speed of light, travelling from liquid to glass, slow down.
(b) Speed in liquids = `"Speed of light of air"/"Refractive index of liquid"=(3xx10^8)/"Refractive index of liquid"`
Speed of light in glass = `"Speed of light in air"/"Refractive index of glass"=(3xx10^8)/"Refractive index of glass"`
Since the refractive index in glass is usually higher than that of liquid, hence the speed of light in glass will be less.
संबंधित प्रश्न
What is a spectrum?
Explain how the formation of a rainbow occurs.
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°
Light of a single colour is passed through a liquid having a piece of glass suspended in it. On changing the temperature of liquid, at a particular temperature the glass piece is not seen. When is the glass piece not seen?
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)?
Four students showed the following traces of the path of a ray of light passing through a rectangular glass slab.

The trace most likely to be correct is that of student
(A) I
(B) II
(C) III
(D) IV
Glass is transparent in nature. Why does glass powder look opaque? When water is poured over it, it again becomes transparent. Why?
Complete the ray diagram showing its emergence into the air after passing through the prism.

