Question

An object is placed at a distance of 10 cm from a convex mirror of focal length 5cm.
Calculate the distance of an image from mirror.

Answer 1

Given,

Object distance = $u=-10cm$

Focal length of the convex mirror = $f=5cm$

To find: Image distance $v=?$

Using mirror formula, $\frac{1}{f}=\frac{1}{v}+\frac{1}{u}$, we get

$\frac{1}{5}=\frac{1}{v}+\frac{1}{-10}$

$\Rightarrow \frac{1}{v}=\frac{1}{5}+\frac{1}{10}=\frac{2+1}{10}=\frac{3}{10}$

$\Rightarrow v=\frac{10}{3}cm=3.33cm$.

So the image is virtual, erect, diminished and formed behind the mirror at a distance of 3.33 cm.