Question

Two vertical plane mirrors are inclined at an angle of 60∘ with each other. A ray of light travelling horizontally is reflected first from one mirror and then from the other. The resultant deviation is

A. 60∘
B. 120∘
C. 180∘
D. 240∘

Answer 1

When light is reflected from two plane mirrors inclined at an angle of 60 degrees, the resultant deviation is 120 degrees.

Step-by-step explanation:

When a ray of light is reflected from one plane mirror followed by another at an angle of 60∘, the resultant deviation is 120∘. This is because the angle of incidence is equal to the angle of reflection for each mirror. When the ray is incident on the first mirror, it is reflected at an angle of 60∘. Then, when the reflected ray is incident on the second mirror, it is again reflected at an angle of 60∘. Therefore, the total deviation is 60∘ + 60∘ = 120∘.