Question

What is the relatiinship between power of lens and focal length

Answer 1

Reciprocal of focal length is known as power of lens in metre

And the unit of power of lens is dioptre

Hope this will help

Answer 2

The diopter is the unit of measure for the refractive power of a lens. 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.