Question

Two mirrors are inclined at an angle θ as shown in the figure. Light rays is incident parallel to one of the mirrors. Light will start retracing its path after third reflection if :

(A)  θ = 45º

(B)  θ = 30º

(C)  θ = 60º

(D)  All three

Answer 1

Correct option  (B) θ = 30º 

Explanation:

(90 – θ) + θ = 90º

or θ = ϕ