AQA GCSE Physics Physics Paper 1 (Higher), June 2023: Question 2
7 marks · Standard Demand difficulty · Short Answer
Determine the specific heat capacity of iron using experimental data and a temperature-time graph, and evaluate the effect of adding thermal insulation.
Practise this questionQuestion
Question text
02 Figure 2 shows the equipment a student used to determine the
specific heat capacity of iron.
The iron block the student used has two holes, one for the heater and one for
the thermometer.
Figure 2
02.1 Before the power supply was switched on, the thermometer was used to measure the
temperature of the iron block.
The student left the thermometer in the iron block for a few minutes before recording
the initial temperature.
Suggest why.
[1 mark]
02.2 Figure 3 shows how the temperature changed after the power supply was
switched on.
Figure 3
The energy transferred to the iron block between 5 and 10 minutes was 26 000 J.
The mass of the iron block was 2.0 kg.
Calculate the specific heat capacity of iron.
Use information from Figure 3 and the Physics Equations Sheet.
[4 marks]
Specific heat capacity = J/kg °C
02.3 The student repeated the investigation but wrapped insulation around the iron block.
*05* What effect will adding insulation have had on the investigation?
[2 marks]
Tick ( ) two boxes.
The calculated specific heat capacity will be more accurate.
The iron block will transfer thermal energy to the surroundings at a lower rate.
The power output of the heater will be lower than expected.
The temperature of the iron block will increase more slowly than expected.
The uncertainty in the temperature measurement will be greater.
Mark scheme
Show the mark scheme
Question 2
AO /
Question Answers Extra information Mark
Spec. Ref.
02.1 so the thermometer temperature 1 AO3
was the same as the 4.1.1.3
temperature of the iron block RPA1
AO /
Spec. Ref.
02.2 Δθ = (54 – 28) = 26 (°C) 1 AO2
4.1.1.3
26 000 = 2.0 × c × 26 allow a correct substitution using 1 RPA1
an incorrect value of Δθ
obtained from the graph
26 000 allow a correct rearrangement
c = using an incorrect value of Δθ
2.0 × 26
obtained from the graph 1
c = 500 (J/kg °C) allow an answer consistent with
their value of Δθ obtained from
the graph
AO /
Spec. Ref.
02.3 the calculated specific heat 1 AO3
capacity will be more accurate 4.1.1.3
RPA1
the iron block will transfer 1
thermal energy to the
surroundings at a lower rate
Total Question 2 7
How to answer it
Required Practical 1: Specific Heat Capacity of Iron
This question assesses practical understanding of AQA Required Practical 1 (Specific Heat Capacity) and Topic 4.1.1.3:
- Understanding experimental precautions (thermal equilibrium).
- Extracting data from a heating graph to calculate specific heat capacity using the equation ΔE = m × c × Δθ .
- Evaluating the effect of insulation on experimental accuracy and heat dissipation to the surroundings.
Initial Temperature Measurement
Suggest why the student left the thermometer in the iron block for a few minutes before recording the initial temperature.
✅ Mark Scheme Answer
So the thermometer temperature was the same as the temperature of the iron block.
💡 Key Knowledge
When placed into the metal block, the thermometer needs time for energy transfer by conduction to occur until both the thermometer and the iron block reach thermal equilibrium (identical temperatures).
❌ Common Errors
- Saying "to let the block warm up" (the heater has not been switched on yet!).
- Vague statements like "to get an accurate reading" without explaining why waiting makes it accurate.
Calculating Specific Heat Capacity from Graph Data
Calculate the specific heat capacity of iron using data between 5 and 10 minutes.
📐 Step-by-Step Calculation
- Read temperatures from Figure 3:
At t = 5 min, θ₁ = 28 °C
At t = 10 min, θ₂ = 54 °C - Calculate temperature change (Δθ):
Δθ = 54 − 28 = 26 °C [1 mark] - State the equation and substitute:
ΔE = m × c × Δθ
26 000 = 2.0 × c × 26 [1 mark] - Rearrange to solve for c:
c = 26 000 / (2.0 × 26) [1 mark]
c = 26 000 / 52 - Calculate final value:
c = 500 J/kg °C [1 mark]
🧠 Exam Technique & Reading the Graph
- Grid scale: On the y-axis, 10 small squares = 10 °C, so 1 small square = 1 °C. Always count carefully from the major gridlines.
- Why between 5 and 10 minutes? The curve levels out at the start because the heater takes time to warm up. The line is straight (linear) between 5 and 10 minutes, showing a steady rate of heating.
- Error carried forward (ECF): If you misread the graph (e.g. read 55 °C instead of 54 °C), you can still score 3 of the 4 marks if your substitution, rearrangement, and final value are consistent.
❌ Common Traps
- Using total time (10 min or 5 min) instead of temperature change: The formula requires temperature change (Δθ), not time!
- Using initial temperature (20 °C): The question specifically specifies between 5 and 10 minutes, not from 0 minutes.
- Forgetting brackets in calculator: Typing 26000 / 2.0 × 26 gives 338 000 because your calculator divides first. Always calculate the denominator first: 26000 / (2.0 × 26) = 500 .
Effect of Insulation on the Investigation
What effect will adding insulation around the iron block have? (Tick two boxes)
✅ Correct Options
- ☑ The calculated specific heat capacity will be more accurate. [1 mark]
- ☑ The iron block will transfer thermal energy to the surroundings at a lower rate. [1 mark]
💡 Why Insulation Improves Accuracy
Without insulation, some thermal energy supplied by the heater escapes into the air rather than heating the block. This makes Δθ smaller than it should be, causing the calculated value of c to be artificially high.
Insulation traps thermal energy inside the block, meaning almost all recorded energy directly increases the block's temperature.
❌ Why the Other Options are Incorrect
- "Power output of the heater will be lower": The heater's power depends strictly on electrical current and potential difference ( P = V × I ), unaffected by insulation.
- "Temperature will increase more slowly": With less heat escaping, the block warms up faster, not slower.
- "Uncertainty in measurement will be greater": Insulation does not affect the resolution or reading accuracy of the thermometer.
Topics
Physics · Required Practicals · P1: Energy · Required Practicals
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Higher), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.