Question

24) A ray of light, incident on a prism at an angle of incidence 60°, emerges perpendicular to the other face. If the angle of prism is 30°, then the deviation suffered by the ray is-
(1) 90° (2) 60° (3) 30° (4) 45°​

Answer 1

Explanation:

incidence angle on one face of a prism, i = 60°

angle of prism, A = 30°

emergent rays that makes an angle 30° with incident ray.

we know, deviation angle, & = angle between incident ray and emergent ray = 30°

using formula, 6 = i + e - A

so, 30° = 60° + e -30°

or, e = 0°

hence, angle made by emergent ray with normal to the face of plane is 0°.

hence, angle made by the emergent ray with second face of prism will be 90°.