$A$ concave mirror of focal length $100 \ cm$ is used to obtain the image of the sun,which subtends an angle of $30'$. The diameter of the image of the sun will be.....$cm$.

If $x$ is the distance of an object from the focus of a concave mirror and $y$ is the distance of the image from the focus, then which of the following graphs is correct between $x$ and $y$?

$A$ convex mirror has a radius of curvature of $22 \; cm$. If an object is placed $14 \; cm$ away from the mirror,then its image is formed at:

The separation between the screen and a concave mirror is $2r$. An isotropic point source of light is placed exactly midway between the mirror and the screen. The mirror has a radius of curvature $r$ and reflects $100\%$ of the incident light. Find the ratio of illuminances on the screen with and without the mirror.

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)

$A$ short straight object of height $100\, cm$ lies before the central axis of a spherical mirror whose focal length has absolute value $|f|=40\, cm$. The image of the object produced by the mirror is of height $25\, cm$ and has the same orientation as the object. One may conclude from the information: