AQA GCSE Combined Science: Trilogy Physics Paper 1 (Foundation), June 2025: Question 5

✅ Correct Answer (Any Two)

• Chemical store (of the fuel) decreases.
• Thermal store (of the engine / exhaust gases / surroundings) increases.
• Kinetic store / energy (of the car / moving engine parts) increases.

🧠 Exam Technique: "Store + Direction"

Always state which store and which direction (increases or decreases):

• Don't just write "heat and movement" — standard GCSE physics terminology requires thermal store and kinetic store.
• Make sure you specify what loses energy (chemical store of fuel) and what gains it (kinetic store of car, thermal store of surroundings).

❌ Common Errors

• Stating "kinetic energy decreases" or forgetting the word store.
• Confusing energy pathways with stores (e.g. saying "heat energy" instead of "thermal store").
• Giving only one store and forgetting this is a 2-mark question asking for different stores.

✅ Question 05.2: Fuel from Plants (1 Mark)

Biofuel

Also acceptable: a named biofuel (such as biodiesel, bioethanol), biogas, or wood.

✅ Question 05.3: Powering Non-Combustion Cars (1 Mark)

(By a) battery OR (by) electricity

Also acceptable: by an electric motor.

💡 Key Knowledge: Biofuels vs Fossil Fuels

• Biofuels: Produced directly from plant or animal material (biomass). They are renewable because crops can be replanted and grown in a short timeframe.
• Carbon neutrality: Burning biofuels releases CO₂ that was absorbed by the plant during photosynthesis fairly recently, unlike fossil fuels which lock carbon away for millions of years.

❌ Common Errors

• 05.2: Writing "petrol" or "coal" thinking they formed from prehistoric plants—these are fossil fuels, not renewable plant fuels made today!
• 05.3: Answering "hydrogen" without mentioning fuel cells, or writing vague answers like "solar energy" without explaining how it powers the car.

✅ Correct Conclusion

Tick Box 1:

"The amount of fossil fuel that is burned to generate electricity each year has decreased."

📐 Data Deduction: Why Box 1 is Correct

1. Look at Figure 6: Total electricity generated fell from ~325 units (2013) to ~275 units (2022). Overall generation is down.
2. Combine with the text: The proportion (percentage) from renewables increased over this same period.
3. Deduction: If total generation is lower AND the renewable share is larger, the fossil fuel share must have dropped substantially.

❌ Common Error: Ticking Box 2 or 3

Many students mistakenly tick "atmospheric CO₂ has decreased" or "temperature rise slowed":

• Global atmospheric CO₂ concentration has continued to rise despite UK cuts.
• Figure 6 only displays UK electricity production, not climate data. Never conclude global climate changes directly from a localized electricity generation graph!

✅ Correct Explanation (2 Marks)

• Point 1 (Scale/Equipment): Many new generators / wind turbines / solar panels are needed (or lots of raw resources/materials are required). [1 mark]
• Point 2 (Consequence): Building this massive infrastructure is very expensive / takes a long time to finance and construct. [1 mark]

🧠 Exam Technique: "Cause & Effect" in Explain Questions

To get both marks on an "Explain one reason" question, you must link two points:

Infrastructure scale (many power stations/turbines need to be manufactured and sited) → Economic burden (extremely high capital cost / takes decades to build).

❌ Common Errors & Examiner Notes

• Ignoring the mark scheme restriction: The mark scheme explicitly states "ignore unreliable". Simply saying "wind doesn't always blow" does not answer why it takes many years to build the transition.
• Giving a one-word answer like "money" or "cost" without explaining why it is expensive (need to build huge numbers of renewable generators).

✅ Hydro-electric Power (1 Mark)

• Loss of habitat / destruction of ecosystems (due to flooding valleys behind dams).
• Also acceptable: disruption to fish migration routes / farmland flooded.

✅ Wind Power (1 Mark)

• Negative visual impact (visual pollution / spoils natural landscape).
• Also acceptable: hazard / dangerous to flying birds or bats; noise pollution.

🧠 Exam Technique: Match the Correct Issue to the Resource

Ensure your answers are resource-specific and strictly environmental:

• Hydro-electric: Flooding large valleys directly causes habitat loss and displaces local wildlife.
• Wind: Turbines alter the landscape (visual impact), create rotational sound (noise pollution), and blades can strike birds.
• Do not mention "costs a lot" or "takes up space" unless framed as an ecological/environmental issue.