You connect a heater for 2 h at 1.5 kW. How much energy did it use?
Q1. You connect a heater for 2 h at 1.5 kW. How much energy did it use?
Answer: 3 kWh
Explanation: Energy in kilowatt-hours equals power in kilowatts multiplied by time in hours: E = P × t = 1.5 kW × 2 h = 3 kWh. Kilowatt-hours are the standard unit used by electricity suppliers for billing purposes.