AQA GCSE Physics Physics Paper 1 (Higher), June 2025: Question 4

8 marks · Low Demand difficulty · Short Answer

Explain environmental impacts of carbon dioxide emissions, interpret lifetime emissions data for petrol and electric cars from a graph, and identify zero-carbon electricity resources.

Practise this question

Question

Question 4 displays sub-questions 4.1 through 4.5. Question 4.1 asks to explain one environmental problem caused by carbon dioxide emissions. Below it is Figure 7, a graph plotting 'Total carbon dioxide emitted in kg' on the y-axis (from 0 to 40 000) against 'Total distance driven in km' on the x-axis (from 0 to 100 000). A solid line for the petrol car begins near 5000 kg at 0 km and rises to about 28 000 kg at 100 000 km. A dashed line for the electric car starts at 8000 kg at 0 km and rises gently to about 13 000 kg at 100 000 km, crossing the petrol car line around 17 000 km. Questions 4.2 and 4.3 ask for values read from this graph. Question 4.4 asks why emissions increase as distance increases for the electric car. Question 4.5 asks to select two energy resources from a list that do not emit carbon dioxide when generating electricity.

Mark scheme

Show the mark scheme Mark scheme table for Question 4. For 04.1: 'carbon dioxide is a greenhouse gas' (1 mark) and 'which causes global warming' (1 mark). For 04.2: 8000 (kg) (1 mark). For 04.3: 17 000 (km), allowing values between 16 000 and 18 000 (1 mark). For 04.4: 'the car / battery needs (re)charging' (1 mark) and '(some of the) electricity has been generated using gas / coal / oil' (1 mark). For 04.5: 'nuclear' (1 mark) and 'solar' (1 mark). Total marks: 8.

How to answer it

Evaluating Lifetime Carbon Emissions: Electric vs Petrol Cars

AQA GCSE Physics • Energy Resources & Environmental Impact

What this question tests

This question assesses your ability to link energy usage with environmental science and extract quantitative data from lifetime emissions graphs:

  • Recall & Explanation: The mechanism of the greenhouse effect and how CO₂ causes global climate change.
  • Data Extraction: Identifying y-intercepts (manufacturing emissions) and intersection points (break-even distance) on a line graph.
  • Critical Thinking: Explaining why "zero-emission" electric vehicles still contribute indirectly to atmospheric CO₂.
  • Classification: Distinguishing between energy resources that release CO₂ during operation and those that do not.

Question 04.1

Environmental Problems Caused by Carbon Dioxide [2 marks]

✅ Correct Answer Breakdown

Any pair linking the mechanism to the effect:

  • Mark 1: Carbon dioxide is a greenhouse gas (or absorbs infrared radiation / causes the greenhouse effect).
  • Mark 2: Causes global warming (or climate change / rising sea levels / extreme weather events).

🧠 Exam Technique: 2-Part Structure

When asked to explain an environmental problem caused by a gas, examiners require a cause-and-effect chain:

  1. The Cause: What property does CO₂ have? (Traps heat / greenhouse gas).
  2. The Impact: What physical change does this produce? (Rising global temperatures / melting polar ice).

❌ Common Errors & Misconceptions

  • Confusing CO₂ with acid rain: Acid rain is caused by sulfur dioxide (SO₂) and oxides of nitrogen (NOₓ), not primarily CO₂.
  • Confusing global warming with the ozone layer: CO₂ does not deplete the ozone layer (CFCs do). Saying "destroys the ozone layer" scores 0 marks.
  • Vague answers: Stating just "it causes pollution" is too vague to earn credit at GCSE.

Question 04.2

CO₂ Emitted During Manufacture of the Electric Car [1 mark]

✅ Correct Answer

8 000 kg

Award 1 mark for exactly 8 000 (kg).

📐 Reading the Graph Step-by-Step

  1. Identify the correct line: The key shows the electric car is the dashed line.
  2. Identify the manufacturing stage: Manufacturing occurs before the car travels any distance ( distance = 0 km ). This is the y-intercept.
  3. Read the scale: On the vertical axis, each large division of 10 small squares = 10 000 kg. Therefore, 1 small square = 1 000 kg.
  4. The dashed line starts at 8 small squares above 0 → 8 × 1 000 = 8 000 kg .

❌ Common Error

Reading the solid line instead of the dashed line gave an answer of 5 000 kg . Always double-check the key!

Question 04.3

Distance Where Total Emissions are Equal [1 mark]

✅ Correct Answer

17 000 km

Allow any value between 16 000 km and 18 000 km.

📐 How to Find the Intersection

  1. Find where the solid line (petrol) and dashed line (electric) cross each other.
  2. Follow the point directly down to the horizontal axis (Total distance driven).
  3. Check axis scale: 10 small squares = 20 000 km → 1 small square = 2 000 km .
  4. The intersection lies halfway between the 8th square (16 000 km) and 9th square (18 000 km) at 8.5 squares → 17 000 km .

Question 04.4

Why Electric Car Emissions Increase with Distance [2 marks]

✅ Correct Answer

  • Mark 1: The car / battery needs to be recharged (uses electricity as it drives).
  • Mark 2: (Some of) the electricity is generated using fossil fuels (allow coal / oil / natural gas) which emit CO₂.

💡 Key Knowledge: Direct vs Indirect Emissions

While an electric car has zero tailpipe (direct) emissions, its operation creates indirect emissions via the national grid.

Unless 100% of the electricity grid comes from renewables or nuclear, generating the electrical energy required to charge the battery releases CO₂ into the atmosphere.

❌ Examiner Commentary: Missed Marks

Many students simply stated "electricity produces carbon dioxide". Electricity itself does not emit gases—it is the combustion of fossil fuels in power stations that produces CO₂. You must mention the source or generation of electricity to secure the second mark.

Question 04.5

Energy Resources that Do NOT Emit CO₂ During Generation [2 marks]

✅ Correct Selections (Tick Two)

  • ☑ Nuclear [1 mark]
  • ☑ Solar [1 mark]

💡 Analysis of All Options

  • Biofuel: ✘ Emits CO₂ when combusted (even though it is renewable and considered carbon-neutral overall).
  • Nuclear: ✔ No CO₂ released during nuclear fission.
  • Oil: ✘ Emits CO₂ as a fossil fuel burned in power stations.
  • Solar: ✔ No CO₂ released when photovoltaic cells generate electricity.
  • Wood: ✘ Emits CO₂ directly when burned.

❌ The "Renewable = Zero CO₂" Trap

Students frequently ticked Biofuel or Wood thinking that because they are renewable, they do not emit CO₂. The question asks what does not emit carbon dioxide when used. Burning biomass always produces CO₂ gas into the immediate atmosphere.

Topics

Physics · P1: Energy

Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Higher), June 2025. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.