The image formed by a convex mirror of focal length $30 \,cm$ is a quarter of the size of the object. The distance of the object from the mirror is (in $\,cm$)

$A$ concave mirror forms a real image three times larger than the object on a screen. The object and screen are moved until the image becomes twice the size of the object. If the shift of the object is $6 \ cm$,find the shift of the screen and the focal length of the mirror.

$A$ convex mirror of focal length $10\,cm$ is shown in the figure. $A$ linear object $AB = 5\,cm$ is placed along the optical axis. Point $B$ is at a distance of $20\,cm$ from the pole of the mirror. Then,the size of the image of $AB$ will be:

If a parallel beam of light is incident on spherical mirrors, then after reflection, they pass through the focal point. If $F$ is the focal length and $R$ is the radius of curvature of the mirror, then:

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

$A$ convex mirror is used to form the image of an object. Then which of the following statements is wrong?