First slide

Ray optics

Question

The velocity of light in a medium is half its velocity in air. If a ray of light emerges from such a medium into air, the angle of incidence, at which it will be totally internally reflected, is

Easy

A

15°
B

30°
C

45°
D

60°

Solution

Max angle is the critical angle, velocity is halved, hence $μ_{r} = 2$
$θ_{C} = S i n^{- 1} \frac{1}{μ_{r}} = S i n^{- 1} \frac{1}{2} = 30^{0}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App