If a 1 kW appliance is used for one hour, how much energy is consumed?

• A. 1 kWh
• B. 1000 kWh
• C. 1 W
• D. 10 kWh

Answer: (A)

The energy consumed by an appliance can be calculated using the formula:

Energy (in kilowatt-hours) = Power (in kilowatts) × Time (in hours).

In this case, you have a 1 kW appliance running for one hour. By plugging in the values:

Energy = 1 kW × 1 hour = 1 kWh.

This shows that the appliance consumes 1 kilowatt-hour of energy when used for one hour. The concept of kilowatt-hours is a standardized measure of electrical energy that reflects both the power rating of the appliance and the duration for which it operates. This understanding is crucial in electrical science, especially in applications related to energy consumption and billing.

The other options do not align with the proper calculation of energy consumption for the given parameters. 1000 kWh would suggest running the appliance at 1 kW for 1000 hours, which is not relevant here. 1 W is the instantaneous power, not an energy measurement over time, while 10 kWh would imply operation at a much higher power for a longer duration than specified.