AQA GCSE Combined Science: Trilogy Physics Paper 1 (Foundation), 2022: Question 6
15 marks · Standard Demand difficulty · Extended Answer
Describe a method to determine specific heat capacity, perform power calculations, and interpret graphs related to thermistors and changes of state.
Practise this questionQuestion
Question text
06 A student made measurements to determine the specific heat capacity of
vegetable oil.
Figure 10 shows the equipment used.
Figure 10
06.1 Describe how the student could use the equipment shown in Figure 10 to determine
the specific heat capacity of vegetable oil.
[6 marks]
06.2 Give one risk when using the equipment in Figure 10.
[1 mark]
A different student did not have a joulemeter and calculated the energy transferred by
the electric heater.
Use the Physics Equations Sheet to answer questions 06.3 and 06.4.
06.3 Write down the equation linking energy transferred (E), power (P) and time (t).
[1 mark]
06.4 The electric heater had a power output of 50 watts.
Calculate the time taken for the electric element to transfer 4750 joules of energy to
the vegetable oil.
[3 marks]
Time taken = s
In a deep fryer, vegetable oil is heated by an electric heating element. Food is then
cooked in the hot vegetable oil.
The deep fryer contains an electrical component to monitor the temperature of the
vegetable oil.
Figure 11 shows how the resistance of this electrical component changes
with temperature.
Figure 11
06.5 What electrical component is used to monitor the temperature of the vegetable oil?
[1 mark]
06.6 The electric heating element in the deep fryer automatically switches off when the
vegetable oil reaches a certain temperature.
Figure 12 shows how the temperature of the vegetable oil changed after the deep
fryer was switched on.
Figure 12
Determine the resistance of the electrical component when the electric heating
element automatically switched off.
Use Figure 11 and Figure 12.
[2 marks]
30 Resistance = Ω
06.7 Some chips were put in the deep fryer.
In the deep fryer, water in the chips underwent a physical change and became steam.
Why is this a physical change?
[1 mark]
Tick ( ) one box.
All water can change to steam.
No chemicals are involved when water changes to steam.
The change from water to steam can be detected visually.
The water will recover its original properties if the steam is cooled.
Mark scheme
Show the mark scheme
Question 6
AO /
Question Answers Mark
Spec. Ref.
06.1 Level 3: The method would lead to the production of a valid 5–6 AO1
outcome. All key steps are identified and logically sequenced. 6.1.1.3
6.3.2.2
Level 2: The method would not necessarily lead to a valid 3–4 RPA14
outcome. Most steps are identified, but the plan is not fully logically
sequenced.
Level 1: The method would not lead to a valid outcome. Some 1–2
relevant steps are identified, but links are not made clear.
No relevant content. 0
Indicative content
• measure mass of oil using the top pan balance
• measure start temperature of oil using the thermometer
• place beaker of oil on heater
• switch on heater to heat oil
• measure final temperature of oil using the thermometer
• measure energy transferred using joulemeter
• calculate increase in temperature (∆θ)
• use the equation E = mcΔθ to determine c
AO /
Question Answers Extra information Mark
Spec. Ref.
06.2 burns / scalds allow cuts from broken glass 1 AO1
6.1.1.3
ignore the heater / oil is hot
RPA14
AO /
Spec. Ref.
06.3 energy transferred 1 AO1
power =
time 6.1.1.4
6.2.4.2
or RPA14
E 17
P =
t
AO /
Spec. Ref.
06.4 4750 1 AO2
50 =
t 6.1.1.4
or 6.2.4.2
4750 = 50 × t
4750
t = 1
t = 95 (s) 1
AO /
Spec. Ref.
06.5 thermistor 1 AO1
6.2.1.4
AO /
Spec. Ref.
06.6 250 (Ω) allow an answer in the range 2 AO3
240 (Ω) to 260 (Ω) 6.2.1.4
allow 1 mark for temperature =
160 (°C)
AO /
Spec. Ref.
06.7 the water will recover its original 1 AO1
properties if the steam is cooled 6.3.1.2
Total Question 6 15
How to answer it
Specific Heat Capacity & Electrical Components
What this question tests
This question assesses your ability to describe the Required Practical (RPA 14) for Specific Heat Capacity, perform energy calculations, identify electrical components from their properties, and interpret data from multiple graphs.
The Specific Heat Capacity Method
6 Marks - Extended Writing
💡 Key Knowledge
To find Specific Heat Capacity (c), you need to measure:
- Mass (m) of the substance.
- Energy transferred (E) to the substance.
- Temperature change (Δθ).
Formula: E = m × c × Δθ
🧠 Exam Technique
For a 6-mark method, use a logical sequence. Look at the equipment provided in the diagram and make sure you mention every piece of it in your answer!
✅ Model Answer (Level 3: 5-6 Marks)
- Place the beaker on the top pan balance and set to zero. Pour in the oil and record the mass.
- Place the thermometer in the oil and record the initial temperature.
- Connect the electric heater to the joulemeter.
- Place the heater into the oil and switch it on.
- After a set time, switch off the heater and record the final temperature.
- Read the energy transferred from the joulemeter.
- Calculate the temperature increase (Δθ = final temp - initial temp).
- Rearrange the equation to calculate c: c = E / (m × Δθ).
Safety and Risks
✅ Correct Answer
Burns or scalds from the hot oil or the heating element.
❌ Common Error
Do not just write "the oil is hot." You must state the risk to the person (the injury), which is a burn or a scald.
Power and Energy Calculations
💡 The Equation
Power = Energy Transferred / Time
Or: P = E / t
📐 Calculation Steps
The Goal: Find the time taken for 4750 J to be transferred by a 50 W heater.
- Identify values: P = 50 W, E = 4750 J.
- Rearrange: t = E / P
- Substitute: t = 4750 / 50
- Solve: t = 95
Final Answer: 95 s [3 Marks]
Identifying Components
💡 Thermistors
A thermistor is a temperature-dependent resistor. In most cases (NTC thermistors), as the temperature increases, the resistance decreases.
✅ Correct Answer
Thermistor
Examiner Note: Figure 11 shows resistance falling as temperature rises, which is the classic "signature" of a thermistor.
Using Multiple Graphs
🧠 Two-Step Graph Reading
This question requires you to link Figure 12 and Figure 11 together.
- Step 1 (Fig 12): Find the temperature where the graph levels off (the "switches off" point). This is 160 °C.
- Step 2 (Fig 11): Go to 160 °C on the x-axis. Move up to the line, then move left to the y-axis to read the resistance.
✅ Correct Answer
250 Ω (Acceptable range: 240 Ω to 260 Ω)
Physical vs Chemical Changes
💡 Physical Changes
In a physical change (like boiling or melting), no new substances are made. The process is reversible—if you reverse the conditions, the substance gets its original properties back.
✅ Correct Box to Tick
"The water will recover its original properties if the steam is cooled."
Topics
Physics · P1: Energy · P2: Electricity · P3: Particle Model of Matter
Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Physics Paper 1 (Foundation), 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.