Question

The focal length of a concave mirror is $50cm.$ Where an object be placed so that its image is two times and inverted

• A. $75cm$
• B. $72cm$
• C. $63cm$
• D. $50cm$

Answer 1

The correct option is A $75cm$

for Real image $m=-2,$ so by using $m=\frac{f}{f-u}$
$\Rightarrow -2=\frac{-50}{-50-u}\Rightarrow u=-75cm$