Advertisements
Advertisements
Question
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.
Advertisements
Solution
(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.
RELATED QUESTIONS
Choose the correct alternative and rewrite the following sentence.
A ray of light strikes the glass slab at an angle of 50°. What is the angle of incidence?
Explain how the formation of a rainbow occurs.
Fill in the blanks to complete the following sentence
The refractive index of glass with respect to air is 3/2. The refractive index of air with respect to glass will be ……………….
Draw an í- `delta` graph for a mono chromatic raY through a glass prism of a plane and mark
(i) `delta` m, the angle of mínimum devíation
(íí) Any two values of i for which value of `delta` ís same.
Fig shows a lens as a combination of a glass block and two prisms.

(i) Name the lens formed by the combination.
(ii) what is the XX' called?
(iii) Complete the ray diagram and show the path of the incident ray PQ after passing through the lens.
(iv) The final emergent ray will either meet XX' at a point or appear to come from a point on XX'. what is the point called?
In the diagram alongside a ray of light, PQ is incident normally on one face AB of an equilateral glass prism. What is the angle of incidence at the faces AB and AC?

The diagram shows the path of a ray of light through a rectangular glass block placed in a liquid of uniform density.

What is the angular, deviation of the emergent ray from the glass block with respect to the incident ray?
The diagram shows the path of a ray of light through a rectangular glass block placed in a liquid of uniform density.

What should be the rate of the speed of light through the liquid to the speed through the glass so that there is no refraction of light at the boundaries of the glass block when the system is illuminated by the light of one colour?
Draw a diagram of a prism and label:
(i) the base,
(ii) the refracting surfaces,
(iii) the refracting edge,
(iv) the refracting angle in it.
