$A$ ray of light is incident on a plane mirror at an angle of $60^{\circ}$. The angle of deviation produced by the mirror is (in $^{\circ}$)

$A$ ray of light travelling in the direction $\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$ is incident on a plane mirror. After reflection,it travels along the direction $\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$. The angle of incidence is: (in $^{\circ}$)

Two plane mirrors are at right angles to each other. $A$ man stands between them and combs his hair with his right hand. In how many of the images will he be seen using his right hand?

$A$ point source of light,$S$,is placed at a distance $L$ in front of the centre of a plane mirror of width $d$ which is hanging vertically on a wall. $A$ man walks in front of the mirror along a line parallel to the mirror,at a distance $2L$ as shown below. The distance over which the man can see the image of the light source in the mirror is:

The focal length of a plane mirror is:

When an object is placed between two parallel mirrors,the number of images formed is: