An object of length 2.0 cm is placed perpendicular to the principal axis of a convex lens of focal length 12 cm. Find the size of the image of the object is at a distance of 8.0 cm from the lens.

Explanation

we have `u=-8.0cm, and f=+12cm`
using `1/v-1/u=1/f`
`1/v=1/(12cm)+1/(-8.0cm)`
or `v=-24cm`
Thus` m=v/u=(-24cm)/(-8.0cm)=3`
Thus`h_2=3 h_1=3xx2.0cm=6.0cm. The positive sign shownn that the image is erect.