Question

State and define the S.I. unit of power of a lens.

Answer 1

Answer:

the SI unit of power of lens is Dioptre which is expressed as D.

1D=1/m¹

Answer 2

Power of lens

Explanation:

(a) The ability of a lens to converge or diverge a beam of the light ray is known as the Power (P) of the lens. Power is equal to the reciprocal of the focal length. So P = 1/f

(b) SI unit of the power of a lens is Dioptre and it is denoted by D.

1 diopter = 1/ 1m = 1 m^-1 where 1 m is the focal length.