The critical angle of incidence in a glass slab immersed in a air is 30°. What will be the critical angle when it is immersed in a medium of refractive index √2?

Question

Question

This question was previously asked in

ALP CBT 2 Physics and Maths Previous Paper 1 (Held On: 21 Jan 2019 Shift 1)

Answer 1

CONCEPT:

Total internal reflection (TIR):

Total internal reflection (TIR) occurs at the interface of two transparent medium when the ray of light travels from a denser medium to a rarer medium.
The critical angle is the angle of incidence in the denser medium for which the angle of refraction in the rarer medium is 90°.
Total internal reflection (TIR) of light is the reflection of light within the same medium when a ray of light is incident at the interface of two medium at an angle of incidence which is greater than the critical angle for the pair of media i.e. i > ic.
The relation between refractive index and critical angle is

\(μ =\frac{1}{\sin C}\)

CALCULATION:

Given - μ = √2

\(\Rightarrow \mu =\frac{1}{\sin C}\)

\(\Rightarrow C={{\sin }^{-1}}\left( \frac{1}{\sqrt 2} \right)={45}^o\)