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प्रश्न
What is total internal reflection?
Explain total internal reflection of light.
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उत्तर
Total internal reflection is the phenomenon when a ray of light travelling in a denser medium is incident at the surface of a rarer medium such that the angle of incidence is greater than the critical angle for the pair of media, and the ray is totally reflected back into the denser medium.
संबंधित प्रश्न
A ray of light travels from water to air as shown in the diagram given below :

1) Copy the diagram and complete the path of the way. Given the critical angle for water is 48°.
2) State the condition so that internal reflection occurs in the above diagram.
State the relation between the critical angle and the absolute refractive index of a medium.
A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incident is ______.
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
Angle of incidence versus angle of reflection,
How does a ray of light bend when it travels from when it is normal to the interface of the two media.
The adjacent diagram shows two right-angled isosceles prisms A and B. Complete the diagram to show the path of rays P and Q emerging out of the prism B. What principles have you used to complete the diagram?

PQ and PR are two light rays emerging from the object as shown in the figure below:

(i) What is the special name given to the angle of incidence (∠PQN) of ray PQ?
(ii) Copy the ray diagram and complete it to show the position of the image of the object P when seen obliquely from above.
(iii) Name the phenomenon that occurs if the angle of incidence ∠PQN is increased still further.
Answer the following question.
Under what conditions are total internal reflection possible? Explain it with a suitable example.
Answer the following question.
Define the critical angle of incidence and obtain an expression for it.
The angle of minimum deviation produced by a thin glass prism in air is 'δ'. If that prism is immersed in water, the angle of minimum deviation will be ______.
( aμg = refractive index of glass w.r.t, air aμw = refractive index of water w.r.t. air)
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 are the conditions to achieve total internal reflection?
What is the phenomenon used in optical fiber? Explain.
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 ______.
Find the value of θ in the given figure.

State two differences between normal reflection and total internal reflection.
