Advertisements
Advertisements
Question
You are given prisms made of crown glass and flint glass with a wide variety of angles. Suggest a combination of prisms which will
(a) deviate a pencil of white light without much dispersion,
(b) disperse (and displace) a pencil of white light without much deviation.
Advertisements
Solution
(a)Place the two prisms beside each other. Make sure that their bases are on the opposite sides of the incident white light, with their faces touching each other. When the white light is incident on the first prism, it will get dispersed. When this dispersed light is incident on the second prism, it will recombine and white light will emerge from the combination of the two prisms.
(b)Take the system of the two prisms as suggested in answer (a). Adjust (increase) the angle of the flint-glass-prism so that the deviations due to the combination of the prisms become equal. This combination will disperse the pencil of white light without much deviation.
RELATED QUESTIONS
State the relation between the critical angle and the absolute refractive index of a medium.
Which colour of light has a higher critical angle? Red light or green light.
State two conditions necessary for total internal reflection to occur.
The diagram below shows a light source P embedded in a rectangular glass block ABCD of critical angle 42°. Complete the path of the ray PQ till it emerges out of the block. [Write necessary angles].
Plot a graph between
Sine of angle of incidence versus sine of angle of refraction,
A ray of light incident at an angle of incidence ‘i’ passes through an equilateral glass prism such that the refracted ray inside the prism is parallel to its base and emerges from the prism at an angle of emergence ‘e’.
What can you say about the value of the angle of deviation in such a situation?
A ray of light is incident on a glass surface at an angle of 50° with the corresponding angle of refraction 30°. Find the value of the R.I. of glass.
Choose the correct option.
Select the WRONG statement.
Explain ‘mirage’ as an illustration of refraction.
Answer the following question.
Why is prism binoculars preferred over traditional binoculars? Describe its working in brief.
The outer concentric shell in optic fiber is called ______.
A bundle of glass threads, each of which is capable of transmitting messages using light waves is called ______.
What is a mirage? How does it occur?
A ray of light incident at an angle θ on a refracting face of a prism emerges from the other face normally. If the angle of the prism is 5° and the prism is made of a material of refractive index 1.5, the angle of incidence is ______.
State the condition under which total internal reflection occurs. Give the mathematical expression for total internal reflection.
A light is entering from one medium refractive index `("RI" =5/3)` to another medium at an angle 30°. The angle of refraction for other medium is sin-1 `(5/6)`. then the increase in angle of incidence is ______ such that the ray of light reflected back into the same medium.
A ray of light passes from vacuum into a medium of refractive index µ, the angle of incidence is found to be twice the angle of refraction. Then the angle of incidence is ______.
- Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface.
- Reason (R): Refractive index of the material of the cladding of the optical fibre is greater than that of the core.
The diagram below shows a fish in the tank and its image seen on the surface of the water.
Name the phenomenon responsible for the formation of this image.
