GCSE Physics resources
AQA GCSE Energy
Measure how electrical energy supplied to a block changes its temperature, then determine specific heat capacity.
Start here
Measure mass, potential difference, current, time and temperature change for a heated block. Electrical energy supplied is E = VIt, and c can be found from E = mcΔθ or the gradient of an energy against temperature-change graph.
Before you revise
Choose an answer from memory. Your result tells you what to watch for in the guide.
Core revision guide
Specific Heat Capacity Required Practical questions become manageable when the central model, evidence and exam method are kept together. Read the explanation, test the misconception and then apply the idea without looking back.
Measure mass, potential difference, current, time and temperature change for a heated block. Electrical energy supplied is E = VIt, and c can be found from E = mcΔθ or the gradient of an energy against temperature-change graph.
The electrical supply transfers energy at a rate P = VI, so the energy supplied is VIt. Not all of this reaches the block: some warms the heater and surroundings. This is why insulation, a lid and a good thermal contact make a fairer measurement.
Electrical energy supplied: E = VIt (J, V, A, s). Specific heat capacity: E = mcΔθ (J, kg, J/(kg °C), °C). Choose each relationship from the physical change described, convert quantities into compatible units and keep the unit beside the final answer.
Misconception clinic
Read each belief, say what is wrong with it, then compare your correction.
Tempting idea: Using final temperature instead of temperature change.
Use instead: Measure mass, potential difference, current, time and temperature change for a heated block. Electrical energy supplied is E = VIt, and c can be found from E = mcΔθ or the gradient of an energy against temperature-change graph.
Tempting idea: Forgetting E = VIt needs seconds.
Use instead: The electrical supply transfers energy at a rate P = VI, so the energy supplied is VIt. Not all of this reaches the block: some warms the heater and surroundings. This is why insulation, a lid and a good thermal contact make a fairer measurement.
Tempting idea: Ignoring energy transferred to the heater and surroundings.
Use instead: Explain the apparatus, controls, energy calculation, graph or equation, energy losses and one realistic improvement.
Retrieval practice
Worked examples
These examples expose the difference between a secure specific heat capacity practical method and the common error “Using final temperature instead of temperature change.”.
E = 4320 J.
c = 600 J/kg °C.
More energy warms the surroundings, so less reaches the block and the calculated SHC is likely too large.
Exam precision
Do this: Explain the apparatus, controls, energy calculation, graph or equation, energy losses and one realistic improvement.
Independent practice
Write an answer before opening the marking guidance. Then edit the exact phrase or step that would gain the next mark.
Marking guidance: Award one mark for the precise statement shown in the model answer.
Model answer: The material of the block.
Marking guidance: Award one mark for the precise statement shown in the model answer.
Model answer: For example, keep block mass, heater power, starting temperature and insulation the same.
Marking guidance: Award up to 3 marks for distinct physics points joined into a clear cause-and-effect chain.
Model answer: Different starting temperatures would otherwise make comparisons unfair; Δθ measures the actual heating.
Marking guidance: Award one mark for the correct relationship, one for a valid substitution and one for the final answer with its unit.
Model answer: E = mcΔθ = 1.0 × 400 × 15 = 6000 J.
Marking guidance: Award one mark for the precise statement shown in the model answer.
Model answer: Wrap the block in insulation or use a lid/insulating jacket while leaving the thermometer and heater in place.
Marking guidance: Award one mark for the correct relationship, one for a valid substitution and one for the final answer with its unit.
Model answer: Plot energy supplied against temperature change; for a fixed mass the gradient is mc, so divide the gradient by mass.
Questions pupils ask
Measure mass, potential difference, current, time and temperature change for a heated block. Electrical energy supplied is E = VIt, and c can be found from E = mcΔθ or the gradient of an energy against temperature-change graph.
Using final temperature instead of temperature change. The electrical supply transfers energy at a rate P = VI, so the energy supplied is VIt. Not all of this reaches the block: some warms the heater and surroundings. This is why insulation, a lid and a good thermal contact make a fairer measurement.
Useful next steps