Question

An object 3 cm in length is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position nature and size of the image.

Answer 1

Given: u = −20 cm

f = R/2 =15 cm

Size of object, h = 3 cm

Let size of image be h′

From mirror formula,

The image is formed 8.57cm behind the mirror. It is virtual and erect.

Magnification, m =−v/u = 8.57/20 = 0.428

Also, m = h′/h = h′/3

From above, h′/3 = 0.428

h′ = 1.284 cm