Find the power of a concave
Question.
Find the power of a concave lens of focal length 2 m.
Find the power of a concave lens of focal length 2 m.
solution:
Given, focal length $=-2 \mathrm{~m}$
(focal length of concave lens is negative).
Power, $P=\frac{1}{f}=\frac{1}{-2.0}$
or $P=-0.5$ Dioptre
Given, focal length $=-2 \mathrm{~m}$
(focal length of concave lens is negative).
Power, $P=\frac{1}{f}=\frac{1}{-2.0}$
or $P=-0.5$ Dioptre