$A$ small object is placed $10\, cm$ in front of a plane mirror. If you stand behind the object $30\, cm$ from the mirror and look at its image,the distance focused for your eye will be........$cm$.

$A$ light beam is being reflected by using two mirrors,as in a periscope used in submarines. If one of the mirrors rotates by an angle $\theta$,the reflected light will deviate from its original path by the angle

Two plane mirrors ${M}_{1}$ and ${M}_{2}$ are at a right angle to each other as shown. $A$ point source $P$ is placed at distances of $a$ and $2a$ meters from ${M}_{1}$ and ${M}_{2}$ respectively. The longest distance between the images thus formed is: (Take $\sqrt{5} = 2.3$)

By what angle should $M_2$ be rotated,so that the light ray after reflection from both mirrors becomes horizontal? (The angle of incidence at mirror $M_1$ is $40^{\circ}$ and the angle between $M_2$ and the horizontal is $25^{\circ}$ as shown in the figure.)

$A$ plane mirror reflecting a ray of incident light is rotated through an angle $\theta$ about an axis through the point of incidence in the plane of the mirror perpendicular to the plane of incidence,then

An object is at a distance of $0.5 \ m$ in front of a plane mirror. The distance between the object and its image is ..... $m$.