Question

what do you mean by power of a lens???? state its SI unit??​

Answer 1

Answer:

The SI unit of power is dioptre (D) which is the inverse of the focal length written in metre (m). ... This means that the lens is a convex lens since a convex lens has a positive focal length. If the power of a lens is negative, from formula (1), it inherently means that the focal length of the lens is negative.

Answer 2

• the power of the lens is the reciprocal of its focal length.
• the SI unit of power is dioptre (D)
• P=1/f
• the power of a lens is negative for the concave mirror
• where as its positive for the convex mirror

HOPE IT HELPS YOU