Question

Calculate distance of an object from height ${}^{\prime }{h}^{\prime }$ of a concave mirror of focal length $=10$ so as to obtain real image of magnification.
$m=-2,v=2u$

Answer 1

By using the formula below and substituting the value of$v=2u$

$m=-\frac{v}{u}$

By substituting all the values in mirror formula we get

$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$

$\frac{1}{-2u}+\frac{1}{-u}=\frac{1}{10}$

Then the height is$15cm$

The image formed will be erected diminished and virtual.