GCSE Physics resources
AQA GCSE Physics exam skills
Practise connecting two physical stages. Keep intermediate values and units visible so a later valid step remains checkable after an arithmetic slip.
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Practise connecting two physical stages. Keep intermediate values and units visible so a later valid step remains checkable after an arithmetic slip.
Before you revise
Choose an answer from memory. Your result tells you what to watch for in the guide.
Core revision guide
Practise connecting two physical stages. Keep intermediate values and units visible so a later valid step remains checkable after an arithmetic slip.
Scope: 8463 and 8464 · Foundation and Higher
A 4 kg mass rises 3 m in 2 s with g = 9.8 N/kg. Useful energy = mgh = 117.6 J and useful power = 58.8 W. If the motor is 70% efficient, input power = useful/0.70 = 84 W. Dividing by efficiency gives a larger input; multiplying would incorrectly make input smaller than useful output.
Scope: 8463 and 8464 · Foundation and Higher
A 12 V, 0.50 A lamp running for 4 min has P = 6 W and E = 6 × 240 = 1440 J. Alternatively Q = 0.50 × 240 = 120 C and E = QV = 1440 J. Matching independent routes checks the method. 4 minutes is not 4 seconds, and 500 mA is not 500 A.
Scope: 8463 and 8464 · Foundation and Higher
Melting ice at 0 °C uses E = mL. Heating the melted water uses E = mcΔθ. Add energies for sequential stages, divide the total by heater power for time, and account for efficiency only if given. Do not substitute zero Δθ into the state-change equation or round each stage before summing.
Misconception clinic
Read each belief, say what is wrong with it, then compare your correction.
Tempting idea: 45 W.
Use instead: Multiplying gives an input smaller than useful output. 60/0.75 = 80 W.
Tempting idea: 2000 C.
Use instead: Both units need conversion. 0.500 × 240 = 120.
Retrieval practice
Worked examples
Apply a lift with efficiency in the worked reasoning, then try the changed-context questions below.
Scope: 8463 and 8464 · Foundation and Higher
84 W input, with 58.8 W useful output and 25.2 W unwanted transfer.
Exam precision
Do this: Write each intermediate result with its unit and retain unrounded values. Check that input exceeds useful output when efficiency is below one.
Independent practice
Write an answer before opening the marking guidance. Then edit the exact phrase or step that would gain the next mark.
Scope: 8463 and 8464 · Foundation and Higher
Original PhysicsUK mark scheme: Point 1 (1 mark): Useful energy = mgh = 5.0 × 10 × 2.0 = 100 J. Point 2 (1 mark): Useful power = 100/4.0 = 25 W. Point 3 (1 mark): Efficiency = 0.80; input power = useful power/efficiency. Point 4 (1 mark): Input power = 25/0.80 = 31.25 W (31 W acceptable). Award each distinct point once. Accept equivalent scientifically correct wording. No half marks.
Model answer: Useful energy = mgh = 5.0 × 10 × 2.0 = 100 J. Useful power = E/t = 100/4.0 = 25 W. Efficiency = 80/100 = 0.80, so input power = useful power/efficiency = 25/0.80 = 31.25 W (31 W to two significant figures). Input exceeds useful output because efficiency is below one.
Marking notes: Carry a numerical error from energy into a correct E/t method, then carry useful power into correct division by 0.80. Do not carry a physically invalid efficiency inversion.
Scope: 8463 and 8464 · Foundation and Higher
Original PhysicsUK mark scheme: Point 1 (1 mark): I = 0.300 A and t = 300 s. Point 2 (1 mark): Q = It = 90 C. Point 3 (1 mark): E = QV = 90 × 6.0 = 540 J. Award each distinct point once. Accept equivalent scientifically correct wording. No half marks.
Model answer: Convert 300 mA to 0.300 A and 5.0 min to 300 s. Q = It = 0.300 × 300 = 90 C. E = QV = 90 × 6.0 = 540 J. Alternatively P = VI = 6.0 × 0.300 = 1.8 W, then E = Pt = 1.8 × 300 = 540 J.
Marking notes: Accept P = VI then E = Pt as an alternative complete method with the same conversions. Later method marks may carry a previous arithmetic error.
Questions pupils ask
Early rounding can change the final result. Round the final answer to an appropriate precision after completing all linked steps.
Useful next steps