Question

A lens mentioned in convex lens has a focal length of 25 cm. Calculate the power of the lens.

Answer 1

Given: f = 25 cm = 0.2 m

Power of a lens is: 

\[ P=\frac{1}{f} \]

= \[\frac{1}{0.25}\]

= 4 D

Since the lens is a convex lens, its power is positive.

P = +4 D