Which unit equals 1,000 watt-hours of energy?

Which unit equals 1,000 watt-hours of energy?

• A. Watt-hour
• B. Joule
• C. Kilowatt
• D. Kilowatt-hour

Answer: (D)

Energy is the amount of work done over time, so it's power multiplied by time. A watt-hour is the energy used when a device runs at one watt for one hour. The prefix kilo means 1000, so a kilowatt-hour is 1000 watt-hours. That makes the kilowatt-hour the unit that equals 1,000 watt-hours. The kilowatt is a unit of power (rate of work) and doesn’t itself represent an amount of energy. A joule is another energy unit, and 1 kilowatt-hour equals about 3.6 million joules, illustrating how large 1 kWh is compared to joules.

Energy is the amount of work done over time, so it's power multiplied by time. A watt-hour is the energy used when a device runs at one watt for one hour. The prefix kilo means 1000, so a kilowatt-hour is 1000 watt-hours. That makes the kilowatt-hour the unit that equals 1,000 watt-hours. The kilowatt is a unit of power (rate of work) and doesn’t itself represent an amount of energy. A joule is another energy unit, and 1 kilowatt-hour equals about 3.6 million joules, illustrating how large 1 kWh is compared to joules.