Question

An object 4 cm high is placed at a distance of 10 cm from a convex mirror of radius of curvature 30 cm. Find the image distance.

• A. 10 cm
• B. - 4 cm
• C. 6 cm
• D. - 5 cm

Answer 1

The correct option is C 6 cm

Object distance, $u=-10cm$
Focal length,
$f=R/2$
$f=+30/2cm$
$f=+15cm$

Using mirror formula:
$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$
$\frac{1}{v}+\frac{1}{-10}=\frac{1}{15}$
$v=6cm$

So, the image distance is + 6 cm.