Question

A 1 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 20cm.The distance of the object from the lens is 15cm.Find the nature, position, size and magnification of the image.

Answer 1

h=1cm
f=20cm
u=-15
1/v-1/u=1/f
1/v+1/15=1/20
1/v=1/20-1/15
1/v=3/60-4/60
1/v=-1/60
v=-60cm
h1/h=v/u
h1=-60/-15
h1=4
m=-60/-15
m=4