An image formed by a convex mirror of focal length $30 \ cm$ is one-fourth the size of the object. The distance of the object from the mirror is ...... $cm$.

Under which of the following conditions will a convex mirror of focal length $f$ produce an image that is erect,diminished and virtual?

Let the transverse magnification produced by a spherical mirror be $m$. Then,for the same position of the object,the longitudinal magnification will be:

$A$ 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:

At what distance in front of a concave mirror of focal length $30\; cm$,should an object be placed (in $cm$) so that its real image of size three times that of the object is obtained?

An object is placed at a distance of $40 \, cm$ from a concave mirror of focal length $15 \, cm$. If the object is displaced through a distance of $20 \, cm$ towards the mirror,the displacement of the image will be: