Question

An object of height 4cm is placed at a distance of 'O' of a convex lens, f=20 cm. Find the approximate ratio of the height of the image to the height of the object ​

Answer 1

Answer:

1/v-1/u=1/f

1/v=1/f+1/u=1/20-1/30

3-2/60=1/60

h'/h=v/u=h'/4=60/-30=h'=-8 cm

Ratio=Height of image / Height of object

=-8/4=-2:1 or

m= - 2

Explanation: