Question

define power of a lens?​

Answer 1

Answer:

The power of a lens is defined as the reciprocal of the focal length. Lens power is measured in dioptres (D). Converging (convex ) lenses have positive focal lengths, so they also have positive power values. Diverging (concave ) lenses have negative focal lengths, so they also have negative power values.

Answer 2

Answer:

If a lens has a shorter focal length it is said to be more powerful. The power of a lens is defined as the reciprocal of the focal length. Lens power is measured in dioptres