Step 1: Definition of Kilowatt-hour.
A kilowatt-hour (kWh) is a unit of energy. It represents the amount of energy consumed when a device with a power rating of 1 kilowatt operates for 1 hour. The energy is calculated as:
Thus, 1 kWh = 1000 watts × 3600 seconds = 3.6 × 10^6 joules.
Step 2: Analyze options.
- (A) Energy: Correct. Kilowatt-hour is a unit of energy.
- (B) Power: Incorrect. Power is measured in watts or kilowatts, not kilowatt-hours.
- (C) Torque: Incorrect. Torque is a rotational force and is measured in newton-meters.
- (D) Force: Incorrect. Force is measured in newtons, not kilowatt-hours.
Step 3: Conclusion.
Kilowatt-hour is a unit of energy.