Question

An image is formed at a distance of 20cm from a concave lens of focal length 30cm find the position of the object

Answer 1

it may be 25 cm in Pakistani language

Answer 2

HELLO DEAR

GIVEN OBJECT DISTANCE(V) = 20 CM

FOCAL LENGTH = 30CM

BY THE LENS FORMULA

$\large \bold{ \frac{1}{f} = \frac{1}{v} - \frac{1}{u} }$

$\large \bf{ \frac{1}{30} = \frac{1}{20} - \frac{1}{u} }$

$\large \bf{ - \frac{1}{u} = \frac{1}{30} - \frac{1}{20} }$

$\large \bf { - \frac{1}{u} = \frac{2 - 3}{60} }$

$\large \bf{ - \frac{ 1}{u} = - \frac{1}{60} }$

so ,u = 60 cm

position of object = centre of conveture

nature of object virtual and erect

HOPE IT HELPS YOU DEAR FRIEND THANKS