This topic is examined in Edexcel 1PH0/1 (Paper 1). Edexcel questions frequently give a scenario (e.g. a tumble dryer running for a given time, a car engine) and ask you to calculate power, compare running costs, or evaluate energy efficiency. The "Suggest" command word is common — be ready to apply power concepts to unfamiliar contexts.
How this topic appears in exams:
- Calculation questions (2-4 marks): Calculate power from energy and time, or rearrange to find time or energy
- Electrical power (2-3 marks): Use P = IV or P = I²R to calculate electrical power
- Energy cost (3-4 marks): Calculate kWh used and find the cost of electricity
- Comparing appliances (2 marks): Explain why a higher-power appliance is not always more expensive to run
- Unit conversions: Convert minutes to seconds, kW to W, etc.
Always show your working and include units at every step. Marks are awarded for substitution and correct units even if the final answer is wrong.
This exam focus covers Exam Focus: Power within Power for GCSE Physics. Revise Power in Energy for GCSE Physics with 14 exam-style questions and 25 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 10 of 12 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Practice questions for Power
Which of the following is the correct definition of power?
A microwave oven transfers 54,000 J of energy. It has a power rating of 900 W. Calculate how long the microwave was switched on. Use the equation: power = energy transferred / time Give your answer in seconds (s).