Question

A convex lens of focal length 5 cm is to be used as a simple microscope. Where should an object be kept so that image formed by the lens lies at least distance D of distinct vision (D = 25 cm)? Also calculate the magnifying power of this instrument in this set up.

Answer 1

Given,

f = 5 cm, v = -25 cm

By lens formula,

Magnifying power,

\(M=1+\frac{D}{f}\)

\(=1+\frac{25}{5}=6\)