Question

Find the value of angle of reflection at plane mirror $M_2$, when a ray of light is incident at $M_1$ as shown in figure.

• A. ${45}^{\circ }$
• B. ${55}^{\circ }$
• C. ${65}^{\circ }$
• D. ${75}^{\circ }$

Answer 1

The correct option is B ${55}^{\circ }$

The ray diagram of reflection of light at two plane mirrors is shown in figure.

The diagram has been made based on the concepts -
(1) The angle of incident $\left(i\right)=$ Angle of reflection $\left(r\right)$
(2) Sum of internal angles of a triangle =${180}^{\circ }$

Hence, from diagram angle of reflection at plane mirror $M_2$ is ${55}^{\circ }.$