Kilowatt-hours are a unit of what quantity?

Kilowatt-hours are a unit of what quantity?

• A. Voltage
• B. Electrical energy
• C. Current
• D. Resistance

Answer: (B)

Kilowatt-hours measure electrical energy. Energy is the amount of work that can be done, and in electricity that work corresponds to power being used over time. The relationship is energy = power × time. A kilowatt-hour represents the energy used when something with a power rating of one kilowatt operates for one hour. For example, a 1 kW appliance running for one hour consumes 1 kWh of energy (about 3.6 million joules). This is the unit used on electricity bills to quantify how much energy was consumed. The other quantities are different: voltage is electric potential difference, current is the flow of electric charge, and resistance is opposition to that flow. Power is measured in watts, while kilowatt-hours are a unit of energy, not power.

Kilowatt-hours measure electrical energy. Energy is the amount of work that can be done, and in electricity that work corresponds to power being used over time. The relationship is energy = power × time. A kilowatt-hour represents the energy used when something with a power rating of one kilowatt operates for one hour. For example, a 1 kW appliance running for one hour consumes 1 kWh of energy (about 3.6 million joules). This is the unit used on electricity bills to quantify how much energy was consumed. The other quantities are different: voltage is electric potential difference, current is the flow of electric charge, and resistance is opposition to that flow. Power is measured in watts, while kilowatt-hours are a unit of energy, not power.