Question

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

• A. $\mu = 1.33$
• B. $\mu = 1.40$
• C. $\mu = 1.50$
• D. $\mu = 1.25$

Answer 1

Answer: (C)

$\mu = 1.50$

Answer 2

: For total internal reflection, sin i> sin C

where,i= angle of incidence, C = critical angle

But, or

$\mu > \sqrt { 2 }$

Hence, option (3) is correct.