Question

explain how power of lens depends on its focal length​

Answer 1

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. Converging (convex ) lenses have positive focal lengths, so they also have positive power values.

Answer 2

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 (D). Converging (convex ) lenses have positive focal lengths, so they also have positive power values.