A ray of light is incident on a 60° prism at the minimum deviation position. The angle of refraction at the first face (i.e; incident face) of the prism is

Question

A ray of light is incident on a 60° prism at the minimum deviation position. The angle of refraction at the first face (i.e; incident face) of the prism is (A) zero (B) 30° (C) 45° (D) 60°

Tardigrade Admin · Accepted Answer

Angle of prism, A =r1+r2 For minimum deviation r1=r2=r ∴ A=2 r Given, A=60° Hence, r=(A/2)=(60°/2)=30°

Q. A ray of light is incident on a $6 0^{\circ}$ prism at the minimum deviation position. The angle of refraction at the first face (i.e; incident face) of the prism is

zero

$3 0^{\circ}$

$4 5^{\circ}$

$6 0^{\circ}$

Angle of prism, $A = r_{1} + r_{2}$
For minimum deviation
$r_{1} = r_{2} = r$
$∴ A = 2 r$
Given, $A = 6 0^{\circ}$
Hence, $r = \frac{A}{2} = \frac{6 0 ^{\circ}}{2} = 3 0^{\circ}$

Q. A ray of light is incident on a 60∘ prism at the minimum deviation position. The angle of refraction at the first face (i.e; incident face) of the prism is