Q. A ray is incident at an angle of incidence $i$ on one surface of a small angle prism (with angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is $\mu$, then the angle of incidence is nearly equal to :
A) $\frac{2A}{\mu}$
B) $\mu A$
C) $\frac{\mu A}{2}$
D) $\frac{A}{2\mu}$
Explanation
[Solution] Normal emergence means $r_2 = 0$, so $r_1 = A$; for small angles $i = \mu r_1 = \mu A$. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.