Question

define the power of lens and state its unit

Answer 1

Power of lens is the ability of the lensto converge the rays of light falling on it. Definition: The power of a lens is the reciprocal of its focal length in meters. It is represented by the letter P. Thepower P of a lens of focal length f is given by f = 1/P. The SI unit of power is dioptre .

Answer 2

Power of lens (P) is defined as the ability of lens to converge/diverge the light rays falling on it. It is the reciprocal of focal length of the lens in metre. P=1/f. Its unit is dioptre (uk) or diopter(us).