Question

draw draw a labelled ray diagram for the formation of image by a convex lens of focal length 15 CM when the object is placed at a distance of 25 cm from the lens determine the size of the image formed if size of the object is 4 cm​

Answer 1

focal length f=15cm

object distance=-25cm

image distance=?

size of object h1=4cm

lens formual

1/v-1/u=1/f

1/v-1/-25=1/15

1/v+1/25=1/15

1/v=1/15-1/25

1/v=5-3/75

1/v=2/75

v=75/2

v=37.5cm

magnification, m=v/u

m=37.5/-25

m=-1.5

Now

m=h2/h1

-1.5=h2/4

h2=-1.5×4

h2=-6cm