A ray of light travelling in a transparent medium of refractive index µ, falls on surface seperating the medium from air at an angle of incidence of 45⁰. For which of the following value of µ the ray can undergo total internal reflection?

Options

(a) µ = 1.33
(b) µ = 1.40
(c) µ = 1.50
(d) µ = 1.25

Correct Answer:

µ = 1.50

Explanation:

For the initial reflection,
µ >= 1 / sin C >= √2 >= 1.414
µ = 1.50