$A$ light bulb is placed between two plane mirrors inclined at an angle of $60^{\circ}$. The number of images formed is:

$A$ 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 $\ldots \ldots \ldots \,cm.$

Ray $1$ is parallel to the horizontal mirror. Ray $2$ is parallel to the other mirror. Then the angle between the two mirrors is .......... $^o$.

Two plane mirrors are placed at an angle of $60^\circ$. $A$ horizontal light ray is reflected by the first mirror and then by the second mirror. The total deviation will be ........... $^\circ$.

$A$ mirror is inclined at an angle of $\theta$ with the horizontal. If a ray of light is incident at an angle $\theta$ with the mirror,then the reflected ray makes the following angle with the horizontal:

$A$ man moves towards a plane mirror with a velocity $v$ in a direction making an angle $\theta$ with the normal to the mirror. The magnitude of the velocity of the image relative to the man is: