Question

what is the power of a len?State the SI unit of a len and how the power of a len is connected to focal length?​

Answer 1

Answer:

The power of a lens is defined as the reciprocal of its focal length. It is represented by P. The SI unit of power is dioptre. The power of a convex lens is positive, the power of a concave lens is negative as a concave lens has a negative focal length.