Question

A ray of light making an angle ${10}^{\circ }$ with the horizontal is incident on a plane mirror making a angle $\theta$ with the horizontal. What should be the value of $\theta$ so that the reflected ray goes vertically upwards?

• A. ${20}^{\circ }$
• B. ${40}^{\circ }$
• C. ${30}^{\circ }$
• D. ${45}^{\circ }$

Answer 1

The correct option is B ${40}^{\circ }$