Running ten 100-Watt bulbs for one hour consumes how many kilowatt-hours?

Running ten 100-Watt bulbs for one hour consumes how many kilowatt-hours?

• A. 1 kWh
• B. 0.1 kWh
• C. 10 kWh
• D. 100 kWh

Answer: (A)

Energy use equals power multiplied by time. Ten bulbs at 100 W each add up to 1000 W, which is 1 kilowatt. Running for one hour means energy consumed is 1 kW × 1 h = 1 kWh. So the total energy is 1 kWh. The other numbers would come from different power or time values—for example, 0.1 kWh would be using 100 W for one hour, 10 kWh would be 10 kW for one hour, and 100 kWh would require 100 kW for one hour (or 1 kW for 100 hours).

Energy use equals power multiplied by time. Ten bulbs at 100 W each add up to 1000 W, which is 1 kilowatt. Running for one hour means energy consumed is 1 kW × 1 h = 1 kWh. So the total energy is 1 kWh. The other numbers would come from different power or time values—for example, 0.1 kWh would be using 100 W for one hour, 10 kWh would be 10 kW for one hour, and 100 kWh would require 100 kW for one hour (or 1 kW for 100 hours).