AQA GCSE Physics
AQA GCSE Physics 4.1.1.3 Energy Changes in Systems Exam Questions
Free AQA GCSE Physics exam questions for 4.1.1.3 Energy Changes in Systems, with a mark scheme for every pack. Covers specific heat capacity, the equation for change in thermal energy, and the required practical measuring specific heat capacity.
4.1.1.3 Energy Changes in Systems exam questions
2 question packs of real past exam questions, each with its mark scheme. Do not stop after a few: answer as many as you can without notes, then mark every answer with the mark scheme. The more questions you do, the more quickly you will spot how examiners ask about each idea.
StemUp mark scheme flashcards
GCSE Physics Triple Science Flashcards for 2027 Onwards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Then test yourself with the questions on this page.
From £7.99View flashcards
About AQA GCSE Physics 4.1.1.3 Energy Changes in Systems
In AQA GCSE Physics, 4.1.1.3 introduces specific heat capacity and the equation for the energy needed to change the temperature of a material. It includes a required practical in which you heat a metal block or water with an electrical heater and calculate its specific heat capacity. This section is examined on Paper 1, and it links closely with 4.3.2.2 in the particle model topic, where the same equation is used in terms of internal energy. Examiners test calculations, explanations of why measured values differ from data book values, and method details from the practical.
What you need to know
- Specific heat capacity The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius. Its unit is J/kg °C.
- The equation Change in thermal energy = mass x specific heat capacity x temperature change: ΔE = m c Δθ. This equation is given on the equation sheet.
- Required practical: method Measure the mass of a block, insert an immersion heater and thermometer, wrap the block in insulation, and record temperature every minute. A joulemeter or a voltmeter, ammeter and stopwatch give the energy supplied (E = P t or E = V I t).
- Required practical: analysis Plot temperature against energy supplied. The gradient is 1 / (m c), so c = 1 / (m x gradient). Using the straight part of the graph avoids the start-up delay while the heater warms.
- Sources of error Energy is lost to the surroundings, so the measured temperature rise is smaller and the calculated value of c is too large. Insulation, a lid and a drop of oil in the thermometer hole reduce this.
- Comparing materials Water has a high specific heat capacity (about 4200 J/kg °C), so it takes a lot of energy to heat and releases a lot when it cools, which is why it is used in central heating and storage heaters.
Common mistakes in 4.1.1.3 Energy Changes in Systems
- Using the final temperature instead of the temperature change. Δθ is final temperature minus initial temperature.
- Stating the definition without 'one kilogram' and 'one degree Celsius'. Both are needed for full marks.
- Saying energy losses make the calculated specific heat capacity smaller. Energy lost to the surroundings means more energy is supplied for each degree, so the value calculated is too high.
- Forgetting to convert mass from grams to kilograms when the specific heat capacity is in J/kg °C.
Try three 4.1.1.3 Energy Changes in Systems exam-style questions
1. Calculate the energy needed to heat 2.5 kg of water from 20 °C to 80 °C. Specific heat capacity of water = 4200 J/kg °C. (2 marks)
Show the mark scheme answer
ΔE = 2.5 x 4200 x 60; = 630 000 J.
2. A 1.0 kg aluminium block is heated by 18 000 J and its temperature rises by 20 °C. Calculate the specific heat capacity of aluminium. (3 marks)
Show the mark scheme answer
c = ΔE / (m Δθ); = 18 000 / (1.0 x 20); = 900 J/kg °C.
3. In the specific heat capacity practical, the value obtained was higher than the accepted value. Explain why and suggest one improvement. (3 marks)
Show the mark scheme answer
Energy was transferred to the surroundings rather than the block; so the temperature rise was smaller than expected for the energy supplied, giving a larger value of c; improvement: wrap the block in more insulation or use a lid.
4.1.1.3 Energy Changes in Systems FAQs
What does AQA GCSE Physics 4.1.1.3 Energy changes in systems cover?
It covers specific heat capacity, the equation ΔE = m c Δθ and the required practical to measure the specific heat capacity of a material.
Which paper is this section on?
It is part of the Energy topic on Paper 1. Specific heat capacity also appears in the particle model section, which is on the same paper.
What should I learn for the specific heat capacity practical?
Know the apparatus, how to calculate the energy supplied using E = V I t or a joulemeter, how to use the gradient of a temperature against energy graph, and why heat loss makes the result too high.
