The kilowatt hour is a unit of
- A. power
- B. energy
- C. current
- D. resistance
Explanation
A kilowatt hour is one kilowatt sustained for one hour, that is 3.6 million joules, and it is the unit an electricity meter records because the joule is inconveniently small for billing. Power is the rate of using energy, measured in watts. Multiplying a power by a time always gives an energy.