Question

A ray of light is incident on a plane mirror at an angle ${50}^{\circ }$. The deviation produced by the plane mirror will be

• A. ${70}^{\circ }$
• B. ${80}^{\circ }$
• C. ${120}^{\circ }$
• D. ${130}^{\circ }$

Answer 1

The correct option is B ${80}^{\circ }$


Deviation produced by plane mirror,
$\delta =180-2\angle i$
$(\because \angle i={50}^{\circ })$
$\Rightarrow \delta ={180}^{\circ }-{100}^{\circ }={80}^{\circ }$
Hence, option $\left(b\right)$ is the correct answer