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प्रश्न
Define critical angle for a given medium.
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उत्तर
When a ray of light propagates from a denser medium to a rarer medium, the angle of incidence for which the angle of refraction is 90° is called the critical angle.
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संबंधित प्रश्न
State two conditions necessary for total internal reflection to occur.
Solve the previous problem if the paperweight is inverted at its place so that the spherical surface touches the paper.
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.
Express the refractive index μ of a medium in terms of the angle of incidence i in air and the angle of refraction r in a denser medium.
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?
How is the critical angle of a material related to its refractive index?
For total internal reflection to take place, the angle of inddence i and the refractive index µ of the medium must satisfy the inequality ____________.
The outer concentric shell in optic fiber is called ______.
The critical angle is defined as the angle of incidence at which the total internal reflection starts to occur.
Observe the given figure of the raindrop and answer the following questions:
- Label A and B of the given diagram. Why colour will deviate most.
- Name the phenomenon shown in label C.
