$A$ point object is placed at a distance of $30 \, cm$ from a convex mirror of focal length $30 \, cm$. The image will form at

$A$ straight metal rod of length $6 \ cm$ is placed along the principal axis of a concave mirror of focal length $9 \ cm$ such that the end of the rod closer to the mirror is at a distance of $15 \ cm$ from the pole of the mirror. The length of the image of the rod is (in $cm$)

$A$ diminished virtual image can be formed only in

An object is placed beyond the centre of curvature $C$ of a concave mirror. If the distance of the object is $d_{1}$ from $C$ and the distance of the image formed is $d_{2}$ from $C$,the radius of curvature of this mirror is

$A$ concave mirror produces an image of an object such that the distance between the object and the image is $20\ cm$. If the magnification of the image is $-3$,then the magnitude of the radius of curvature of the mirror is: (in $cm$)

$A$ boy stands straight in front of a mirror at a distance of $30 \ cm$ away from it. He sees his erect image whose height is $\frac{1}{5}$ of his real height. The mirror he is using is