Lesson 6.22
Kilowatt-Hours
A unit of energy equal to the energy transferred by a 1 kW appliance…
Lesson objectives
Explain the kilowatt-hour as a unit of energy, and calculate the energy used and the cost of running household appliances.
Lesson content
1The Kilowatt-Hour
A unit of energy equal to the energy transferred by a 1 kW appliance…
2Calculating Energy and Cost
Convert the power of the appliance into kilowatts by dividing its power in watts…
3Energy Equations
Energy (kWh) = power (kW) × time (h), so a 2 kW appliance used…
4Worked Example
Question: A 2.0 kW electric heater is used for 3.0 hours. Electricity costs 30…
5Exam Checklist & Tips
6.5.3 – Key Points for the Exam Kilowatt-hour (kWh): A unit of energy equal…
Lesson progress0%Start part 1: The Kilowatt-Hour