Question

define the power of lens state and define so unit of power​

Answer 1

Answer:

unit of power is measured in diopters

The power of a lens is the reciprocal of its focal length, more technically, its second principal focal length. In S.I. its unit is dioptre which is equal to per meter. So we can say that if focal length of a lens is 2 m, its power is 0.5 dioptre.

hope this helps you bro✌✌

Answer 2

Answer:

SI UNIT = Dioptre

Explanation:

The power of a lens is defined as the reciprocal of its focal length in meters, or D = 1/f, where D is the power in diopters and f is the focal length in meters. Lens surface power can be found with the index of refraction and radius of curvature.

A dioptre 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.) It is thus a unit of reciprocal length.