$A$ man having height $6 \ m$ observes an erect image of height $2 \ m$. The mirror used is:

$A$ square cardboard of side $3\, cm$ is placed $25\, cm$ from a concave mirror of focal length $10\, cm$. What is the area enclosed by the image of the cardboard? (The plane of the cardboard is perpendicular to the principal axis.)

An infinitely long rod lies along the axis of a concave mirror of focal length $f$. The nearer end of the rod is at a distance $u$ $(u > f)$ from the mirror. Its image will have a length:

Draw the ray diagram when an object is placed between the focus $(F)$ and the pole $(P)$ of a concave mirror.

The distance between an object and its image (magnified by $-\frac{1}{3}$) is $30 \ cm$. The focal length of the mirror used is $\left(\frac{x}{4}\right) \ cm$,where the magnitude of the value of $x$ is . . . . . . .

An object is gradually moving away from the focal point of a concave mirror along the axis of the mirror. The graphical representation of the magnitude of linear magnification $(m)$ versus distance of the object from the mirror $(x)$ is correctly given by
(Graphs are drawn schematically and are not to scale)