Question

A ray of light is incident normally on one face of a right angled isosceles prism. It then grazes the hypotenuse. The refractive index of the material of the prism is

• A. 1.732
• B. 1.5
• C. 1.414
• D. 1.33

Answer 1

Answer: (C)

1.414

Answer 2

Refractive index, $\mu = \frac{1}{sin C'}$
where C is the critical angle.

Here, $C = 45^{\circ}$ (as shown)
$\mu = \frac{1}{sin 45 ^{\circ}}$
or $\mu = \sqrt{2}$
or $\mu = 1.414$