Question

Two vertical plane mirrors are inclined at an angle of ${60}^{\circ }$ 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. ${60}^{\circ }$
• B. ${120}^{\circ }$
• C. ${180}^{\circ }$
• D. ${240}^{\circ }$

Answer 1

The correct option is D ${240}^{\circ }$

By using $\delta =(360-2\theta )\Rightarrow \delta =360-2\times 60={240}^{\circ }$