Question

Two plane mirror are inclined to one another at an angle of ${60}^o$. A ray is incident on mirror $M_1$ at an angle $i$. The reflected ray from mirror $M_2$ is parallel to mirror $M_1$as shown in figure. The angle of incidence $i$ is:

Answer 1

It is given that final ray is parallel to M₁.

So,

$30+i=90-i$

$2i=60$

$i={30}^0$