$A$ convex mirror of focal length $f$ is placed at the origin with its reflecting surface towards the negative $x-$ axis. Choose the correct graph between $v$ and $u$ for $u < 0$.

Two objects $A$ and $B$ are placed at $15\,cm$ and $25\,cm$ from the pole in front of a concave mirror having a radius of curvature $40\,cm$. The distance between the images formed by the mirror is $..........\,cm$.

In the case of a spherical mirror,if the object distance $(u)$ and image distance $(v)$ are measured from the pole,then the graph plotted between $(1/u)$ and $(1/v)$ will be:

$A$ diminished virtual image can be formed only in

The focal length of a concave mirror is $f$ and the distance from the object to the principal focus is $x$. The ratio of the size of the image to the size of the object is

$A$ convex lens (of focal length $20\, cm$) and a concave mirror,having their principal axes along the same lines,are kept $80\, cm$ apart from each other. The concave mirror is to the right of the convex lens. When an object is kept at a distance of $30\, cm$ to the left of the convex lens,its image remains at the same position even if the concave mirror is removed. The maximum distance of the object for which this concave mirror,by itself,would produce a virtual image would be.....$cm$.