Physics

Problem

Passage 3 (Questions 74-76) When two plane mirrors subtend an angle

\theta

between them, then a ray of light incident parallel to one of them retraces its path after

n

reflections such that

n\theta = c

(where

c

is a constant) What is the value of

c

? (a)

\pi

(b)

\frac{\pi}{2}

(c)

\frac{3\pi}{2}

(d) None of these