Two plane mirrors are inclined to each other such that a ray of light incident to the first mirror $(M_1)$ and parallel to the second mirror $(M_2)$ is finally reflected from the second mirror $(M_2)$ parallel to the first mirror $(M_1).$ The angle between the two mirrors will be......$^o$

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Two plane mirrors $A$ and $B$ are placed parallel to each other as shown in the figure. $A$ light ray is incident on mirror $A$ at an angle of $30^o$. The plane of incidence coincides with the plane of the figure. What is the maximum number of reflections (including the first one) the ray will undergo before emerging?

$A$ man runs towards a plane mirror at a speed of $15 \, m/s$. The speed of the image relative to the mirror is ...... $m/s$.

To obtain $3$ images using two plane mirrors, they should be placed at an angle of ....... $^o$.

The figure shows two rays $A$ and $B$ being reflected by a mirror and emerging as $A'$ and $B'$. The mirror