Question

An object is 14 cm in front of a diverging lens that has a focal length of -6.4 cm. How far in front of the lens should the object be placed so that the size of its image is reduced by a factor of 2.2?

Answer 1

focal length of the diverging lens, f = -6.4cm

object distance, u = -14cm.

let, the image distance be v

The size of the image is reduced by a factor of 2.2.

Let the new object distance be u'.

v / u'= magnification = ( 1 / (2.2)) ;

The object should be placed at a distance of 7.68 cm in order for the image to be reduced by a factor of 2.2