Advertisements
Advertisements
Question
Draw diagram to illustrate the total internal reflection.
Advertisements
Solution
When the incidence angle is greater than the critical angle, i.e., in the case of total internal reflection.

APPEARS IN
RELATED QUESTIONS
The diagram below shows a point source P inside a water container. Four rays A, B, C, D starting from the source P are shown up to the water surface

1) Show in the diagram the path of these rays after striking the water surface.
The Critical Angle for the water-air surface is 48°.
2) Name the phenomenon which the rays B and D exhibit.
The observation made by Swarali while doing the experiment is given below. Based on these write answers to the questions:
Swarali found that the light ray travelling from the denser medium to rarer medium goes away from the normal. If the angle of incidence (i) is raised by Swarali, the angle of refraction (r) went on increasing. However, after certain value of the angle of incidence the light ray is seen to return back into the denser medium.
Questions:
- What is the specific value of∠i called?
- What is the process of reflection of incident rays into denser medium called?
- Draw the diagrams of three observations made by Swarali.
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].

How are critical angles related to the refractive index of the medium?
Name the factors affecting the critical angle for the pair of media.
A ray of light is incident as a normal ray on the surface of separation of two different mediums. What is the value of the angle of incidence in this case?
Answer the following question.
What are the advantages of optical fibre communication over electronic communication?
The critical angle is defined as the angle of incidence at which the total internal reflection starts to occur.
What is a mirage? How does it occur?
State two differences between normal reflection and total internal reflection.
