Question

4cm focal length..find power of lens !?​

Answer 1

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.

So,

0.25 is the required answer

Hope it helps ❤️