Question

what is power of less?define unit​

Answer 1

Answer:

Watt

Power/SI units

In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal to one joule per second. In older works, power is sometimes called activity.

Answer 2

Answer:

Power of lens is the reciprocal of it's focal length, more technically , it's second principle focal length. In it's S.I units is dioptre which is equal to pre meter. So we can say that if focal length of lens is 2m, it's power is 0.5 dioptre.