Question

what is the unit for power? Explain power?

Answer 1

The standard metric unit of power is the Watt. As is implied by the equation for power, a unit of power is equivalent to a unit of work divided by a unit of time. Thus, a Watt is equivalent to a Joule/second. For historical reasons, the horsepower is occasionally used to describe the power delivered by a machine.

Answer 2

Answer:

1. Power refers to reciprocal of the focal length.
2. It's unit is dioptre denoted by the letter D