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प्रश्न
The refractive index of air with respect to glass is expressed as `""_g μ_a=sin i /sin r`.
- Write down a similar expression for aμg in terms of the angles i and r.
- If angle r = 90°, what is the corresponding angle i called?
- What is the physical significance of the angle i in part (b)?
उत्तर
- R.I of glass w.r.t. air `= ""_aμ_g = sini/sinr`
∠r is angle of incidence in air
∠i is angle of refraction in medium - When angle r = 90°
∴ sin 90° = 1 in air
Angle i in medium is called the critical angle. - The significance of ∠i = ic = critical angle is:
The refractive index of the denser medium relative to the rarer medium can be computed using the critical angle value.
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|
S.NO. |
∠i |
∠r |
∠e |
|
I |
60° |
40° |
61° |
|
II |
50° |
36° |
51° |
|
III |
40° |
28° |
39° |
|
IV |
30° |
20° |
31° |
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(A) I
(B) II
(C) III
(D) IV
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