Electricity: Exam Practice

This lesson brings together all the topics from the AQA GCSE Physics Electricity unit (4.2) and provides structured exam practice. You will review the key equations, common question types, mark scheme expectations and strategies for maximising your marks on electricity questions.

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Key Equations Summary

You must know and be able to use all of the following equations. Some are given on the AQA equation sheet; others must be memorised.

Equations You Must Memorise

Equation	Meaning
Q = I x t	Charge = current x time
V = I x R	Potential difference = current x resistance
P = I x V	Power = current x potential difference
P = I^2 x R	Power = current squared x resistance
E = P x t	Energy transferred = power x time
E = Q x V	Energy transferred = charge x potential difference

Equations Given on the AQA Equation Sheet

Equation	Meaning
V(p)/V(s) = n(p)/n(s)	Transformer equation (ratio of voltages equals ratio of turns)