$A$ virtual image three times the size of the object is obtained with a concave mirror of radius of curvature $36 \ cm$. The distance of the object from the mirror is ........ $cm$.

The shape of the image formed of an object $AB$ due to the concave mirror shown in the figure is best represented by (assume point $A$ is at the centre of curvature of the mirror):-

What will be the height of the image (in $mm$) when an object of $2 \, mm$ is placed on the axis of a convex mirror at a distance of $20 \, cm$,given the radius of curvature is $40 \, cm$?

$A$ spherical mirror is obtained as shown in the figure from a hollow glass sphere. If an object is positioned in front of the mirror,what will be the nature and magnification of the image of the object? (Figure drawn as schematic and not to scale)

$A$ $4.5 \;cm$ needle is placed $12 \;cm$ away from a convex mirror of focal length $15 \;cm$. Give the location of the image and the magnification. Describe what happens as the needle is moved farther from the mirror.

$A$ boy stands $30 \,cm$ in front of a mirror. The height of his erect image is $1/5 \,th$ of his actual height. The mirror used is ..... .