What is meant by magnification? Write the formula for finding magnification by a spherical mirror.

Magnification is the ratio of image height and object height. So mathematically we can write,

$m=\frac{h_i}{h_o}$

where $m=$magnification,

$hi=$ height of image formed by the mirror

$ho=$ height of object.

This formula can also be written in terms of object distance and image distance.

$m=-\frac{v}{u}$, where $v$ is the image distance and $u$ is the object distance.