Question

Vertical plane mirrors are inclined at an angle of 60^o 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. 60⁰
• B. 120⁰
• C. 180⁰
• D. 240⁰

Answer 1

Answer: (D)

240⁰

Answer 2

By using $\delta = ( 360 - 2 \theta )$

$\delta = 360 - 2 \times 60 = 240 ^ { \circ }$