The kilowatt hour is a unit of
Correct answer: B. energy
- 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.
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About Maximum Power Output
Maximum power output describes the condition in which a source with internal resistance delivers the greatest power to an external load. The topic uses P = I²R and related circuit equations to show that maximum power occurs when load resistance equals internal resistance. This differs from maximum efficiency, which occurs under a separate condition.
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