$A$ light ray is incident perpendicular to the plane of a mirror. The angle of reflection will be ......$^o$.

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?

$A$ light ray makes an angle of $10^{\circ}$ with the horizontal. It is incident on a plane mirror which makes an angle $\theta$ with the horizontal. If the reflected ray travels in the vertically upward direction,then $\theta = .....^{\circ}$

Light rays fall on a plane mirror and form a real image. Therefore,the incident rays are:

Two plane mirrors $AB$ and $AC$ are inclined at an angle $\theta = 20^{\circ}$. $A$ ray of light starting from point $P$ is incident at point $Q$ on the mirror $AB$,then at $R$ on mirror $AC$,and again at $S$ on $AB$. Finally,the ray $ST$ goes parallel to mirror $AC$. The angle which the ray makes with the normal at point $Q$ on mirror $AB$ is: (in $^{\circ}$)

An object is placed between two plane mirrors inclined at some angle to each other. If the number of images formed is $7$, then the angle of inclination is: (in $^{\circ}$)