Question

A lens of focal length 50 cm is being used by a student in the laboratory as a magnifying glass . His least distance of distinct vision is 25 cm . What magnification of the media

Answer 1

the given lens is a convex lens.so its focal length should be positive.then f=+50cm.and u(object distance) =-25cm.
by the lens formula , 1/v-1/u=1/f.so
v=-50cm.and hence magnification=1