Question

what do you mean by power of a lens? how does it depend upon the focal length? what is the meaning of positive and negative power
plz tell​

Answer 1

Answer:

Power of lens is the ability to converge or diverge the rays of light while passing through the lens. It is positive for Convex lens. It is negative for Concave lens. ... Concave lens is a diverging lens and have negative power. One diopter is defined as power when focal length of the lens is one meter.

Answer 2

Explanation:

power of a lens can be defined as reciprocal of focal length of a lens. it is positive for convex lens and negative for concave lens