Question

a convex lens of focal length 20cm from an object one fourth of the size of the object then the position of the image from the object.​

Answer 1

Answer:

Given f=20cm

m=1/2

but,m=-v/u

1/2=-v/u

v=-u/2

1/v=-2/u

We know 1/f=1/u+1/v

=1/20=1/u-2/u

=-1/u=1/20

=u=-20

The answer is 20 cm behind the lens.

Explanation: