Question

Power of a lens is the reciprocal of its focal length. With is the Sl unit of power of a lens​

Answer 1

Answer:

Dioptre

A lens is said to have a power of one dioptre, if it focal length is one metre

Answer 2

Answer:

dioptre........

• A dioptre or diopter is a unit of measurement of the optical power of a lens or curved mirror,
• which is equal to the reciprocal of the focal length measured in metres.
• (1 dioptre = 1 m−1.)