For a plane mirror,the focal length is . . . . . . $m$.

$A$ watch shows time as $3:25$ when seen through a mirror,the time appeared will be

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

$A$ ray of light making an angle $10^o$ with the horizontal is incident on a plane mirror making an angle $\theta$ with the horizontal. What should be the value of $\theta$ so that the reflected ray goes vertically upwards?

The light reflected by a plane mirror may form a real image:

$A$ point object is kept in front of a plane mirror. The plane mirror is performing $SHM$ with an amplitude of $2 \ cm$. The plane mirror moves along the $x$-axis,and the $x$-axis is normal to the mirror. The amplitude of the mirror is such that the object is always in front of the mirror. The amplitude of the $SHM$ of the image is ....... $cm$.