Question

An object is placed at a distance of $12$cm from a convex lens of focal length $8$cm. Find the position of the image.

Answer 1

Focal length of convex lens, $f=8cm$

Object distance, $u=-12cm$

Using lens formula $\frac{1}{v}-\frac{1}{u}=\frac{1}{f}$
where $v$ is the image distance.

$\therefore$ $\frac{1}{v}-\frac{1}{-12}=\frac{1}{8}$

$⟹v=+24cm$

(+ve sign indicates that image is formed behind the lens)

So, image is formed at a distance $24cm$ behind the convex lens.