Electrical energy transferred by an appliance can be measured in Joules (J\text{J}J).
How do you calculate this energy in Joules?
Divide power in watts by time in seconds.
Divide power in kilowatts by time in hours.
Multiply power in watts by time in seconds.
Multiply power in kilowatts by time in hours.
37 exam-style questions on OCR GCSE Physics Power and efficiency. Each one has a worked solution and a mark scheme showing where the marks go.