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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
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.
A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incident is ______.
(i) Define critical angle.
(ii) State one important factor which affects the critical angle of a given medium.
Plot a graph between
Sine of angle of incidence versus sine of angle of refraction,
Answer the following question.
Under what conditions are total internal reflection possible? Explain it with a suitable example.
Solve Numerical example.
A monochromatic ray of light is incident at 37° on an equilateral prism of refractive index 3/2. Determine angle of emergence and angle of deviation. If angle of prism is adjustable, what should its value be for emergent rays to be just possible for the same angle of incidence?
For total internal reflection to take place, the angle of inddence i and the refractive index µ of the medium must satisfy the inequality ____________.
For a ray of light, the critical angle is minimum when it travels from ______.
The phenomena involved in the reflection of radiowaves by ionosphere is similar to ______.
A rectangular block of glass ABCD has a refractive index 1.6. A pin is placed midway on the face AB (Figure). When observed from the face AD, the pin shall ______.
- appear to be near A.
- appear to be near D.
- appear to be at the centre of AD.
- not be seen at all.
