To get three images of single object, one should have two plane mirrors at an angle of

Options

(a) 60⁰
(b) 90⁰
(c) 120⁰
(d) 30⁰

Correct Answer:

90⁰

Explanation:

Consider the diagram where two plane mirrors are inclined at an angle θ. Number of images formed in given by,
n = (360⁰/θ) – 1 ⇒ 3 = (360⁰/θ) – 1 ⇒ 360⁰/θ = 4 ⇒ θ = 90⁰