$A$ plane mirror rotating at an angular velocity of $3 \; rad/s$ reflects a light beam. The angular velocity of the reflected beam is ........ $rad/s$.

$A$ ray gets successively reflected from two mirrors inclined at an angle of $40^o$. If the angle of incidence on the first mirror is $30^o$,then the net deviation of this ray after two reflections is: (in $^o$)

When a plane mirror is rotated through an angle $\theta$,the reflected ray turns through an angle $2\theta$. What happens to the size of the image?

Digital movie projectors work on the principle of

$A$ point source of light $S$ at a distance $d$ from the screen $A$ produces light intensity $I_0$ at the centre of the screen. If a completely reflecting mirror $M$ is placed at a distance $d$ behind the source as shown in the figure,treating the object and its image as incoherent with each other,find the intensity at the centre of the screen.

$A$ point source of light $S$,placed at a distance $60 \,cm$ in front of the centre of a plane mirror of width $50 \,cm$,hangs vertically on a wall. $A$ man walks in front of the mirror along a line parallel to the mirror at a distance $1.2 \,m$ from it (see in the figure). The distance between the extreme points where he can see the image of the light source in the mirror is $\ldots \ldots \ldots \,cm.$