Q. A ray of light is incident at $60{^\circ}$ on one face of a prism which has angle $30{^\circ}$. The angle between the emergent ray and incident ray is $30{^\circ}$. What is the angle between the ray and the face from which its emerg?
A) $0{^\circ}$
B) $30{^\circ}$
C) $60{^\circ}$
D) $90{^\circ}$
Explanation
(d) Here, $i_{1} = 60{^\circ},A = 30{^\circ},\delta = 30{^\circ}$
As $i_{1} + i_{2} = A + \delta_{,}$
$i_{2} = 0$
Hence, angle between the ray and the face from which it emerges $= 90{^\circ} - 0{^\circ} = 90{^\circ}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.