Question

A convaxe produces magnification half when the object is placed at distance of 0.6m from it. Where should the object be placed so that image size becomes 1/3 of object.

Answer 1

v/u=1/2
when u=-0.6m
hence v=-0.3m

when v/u=1/3
then u=-0.3*3=-0.9m
this means it should be kept at a distance of 0.9m in front of the lens.