AQA GCSE Physics Physics Paper 1 (Higher), November 2020: Question 4

9 marks · Standard Demand difficulty · Short Answer

Analyze electricity generation trends from coal and gas, environmental advantages of gas over coal, sea surface temperature changes over time in relation to climate change, and select the most suitable thermistor to measure sea temperature.

Practise this question

Question

Figure 6 is a bar chart comparing electricity generated in MJ by coal and gas-fired power stations from 2014 to 2018. Figure 7 is a line graph showing the mean surface temperature in degrees Celsius from 1988 to 2016. Figure 8 is a line graph of resistance in kilo-ohms against temperature in degrees Celsius for four different thermistors A, B, C, and D, followed by tick boxes and answer lines.
Question text

04 Figure 6 shows how much electricity was generated using coal-fired and gas-fired

power stations in January for 5 years in the UK.

Figure 6

04.1 Determine the percentage increase in electricity generated using gas-fired power

stations from 2014 to 2018.

[2 marks]

Percentage increase = %

04.2 Give two environmental advantages of using a gas-fired power station to generate

electricity compared with using a coal-fired power station.

[2 marks]

The mean surface temperature of the sea changes throughout the year.

A change in the mean surface temperature from year to year indicates climate

change.

Figure 7 shows how the mean surface temperature changed between 1988 and

2016.

Figure 7

04.3 A student does not believe that climate change is occurring.

Explain how the data in Figure 7 suggests the student is wrong.

[2 marks]

04.4 A thermistor can be used to measure temperature.

Figure 8 shows how the resistance of four different thermistors A, B, C and D, varies

with temperature.

Figure 8

Which of the four thermistors would be the most suitable to measure the surface

temperature of the sea?

Tick ( ) one box.

Explain your answer.

[3 marks]

A B C D

Mark scheme

Show the mark scheme The mark scheme provides answers and marks for four sub-questions: 04.1 requires a percentage increase calculation giving 212.5%, 04.2 asks for two environmental advantages of gas over coal, 04.3 explains how Figure 7 shows an increase in sea surface temperature, and 04.4 identifies thermistor C with reasoning about the greatest resistance change between 0 and 25 degrees Celsius.

Question 4

AO /

Question Answers Extra information Mark

Spec. Ref.

04.1 % increase = AO3

(10 000 - 3200) 1 4.1.3

× 100

3200

% increase = 212.5 (%) 1

04.2 Any two from: 2 AO1

• no sulfur dioxide released 4.1.3

• doesn’t cause acid rain

• no particulates released

• doesn’t cause global dimming

• less carbon dioxide released

(per kg of fuel burned)

• less global warming allow less climate change

allow less greenhouse gases

• no solid waste

• gas mining is less destructive

than coal mining

ignore less air pollution

04.3 mean sea surface temperature 1 AO3

shows a (steady) increase 4.1.3

over the time period on the graph conditional on scoring 1st 1

marking point

allow between a correct pair of

or dates at least 10 years apart

from 16.45 (°C) to 16.96 (°C) allow a correct pair of

temperatures at least 10 years

apart

Question Answers Extra information Mark AO /

Spec. Ref.

04.4 thermistor C 1 AO3

4.2.1.4

(because) the change in conditional on scoring 1st 1

resistance is greatest marking point

allow the gradient is highest

allow more sensitive to

temperature change

between 0 and 25 ºC conditional on scoring 2nd 1

marking point

allow between 16 and 17 ºC

if thermistor C is not chosen,

allow for 1 mark each:

not thermistor A because there

is no/little change in resistance

not thermistor B as there is only

a small change in resistance

not thermistor D as there is no

data available between 0 and

40 ºC

Total 9

How to answer it

Energy Resources, Climate Data & Thermistors

What this question tests

This multi-part question assesses your ability to extract and interpret data from bar charts and line graphs, calculate percentage increases, recall environmental impacts of fossil fuels, analyse climate change evidence, and select appropriate electronic components (thermistors) based on graphical sensitivity curves.

Question Part 04.1

Percentage Increase Calculation

✅ Correct Answer

Percentage increase = 212.5%

Awarded 2 marks (1 mark for correct substitution into the formula, 1 mark for the final correct answer).

📐 Step-by-Step Calculation

  1. Find the starting value (2014): Gas value from Figure 6 = 3200 MJ.
  2. Find the final value (2018): Gas value from Figure 6 = 10000 MJ.
  3. Calculate change: 10000 - 3200 = 6800
  4. Apply formula: (Change / Original) × 100
    ⇒ (6800 / 3200) × 100 = 212.5%

❌ Common Errors

  • Using coal values instead of gas values.
  • Dividing by the final value (10000) instead of the initial starting value (3200).
  • Forgetting to multiply by 100 to convert the decimal into a percentage.
Question Part 04.2

Environmental Advantages of Gas vs Coal

✅ Correct Answers (Any two)

  • No sulfur dioxide released / doesn't cause acid rain.
  • No particulates released / doesn't cause global dimming.
  • Less carbon dioxide released (per kg of fuel burned) / less global warming / less greenhouse gases.
  • No solid waste / gas mining is less destructive than coal mining.
2 marks total (1 mark for each valid point up to a maximum of 2).

💡 Key Knowledge

Coal contains sulfur impurities which burn to form sulfur dioxide gas, leading to acid rain. Coal also produces solid ash waste and soot particulates. Natural gas is a cleaner-burning fossil fuel.

🧠 Exam Technique

Be specific! Examiners reject vague answers like "less pollution" or "better for the environment". You must state what is reduced or avoided (e.g., sulfur dioxide, carbon dioxide, or particulates).

Question Part 04.3

Interpreting Climate Data

✅ Correct Answer

The mean sea surface temperature shows an overall/steady increase over the time period on the graph (or quotes values rising from 16.45 °C in 1988 to 16.96 °C in 2016).

2 marks total. Note: The second marking point is conditional on scoring the first.

🧠 Exam Technique

When asked to explain why a student is wrong based on a graph, look at the overall trend (line of best fit / general direction) rather than getting distracted by small temporary dips or fluctuations in individual years.

Question Part 04.4

Thermistor Selection & Analysis

✅ Correct Answer

Thermistor C ticked.

Reason: The change in resistance is the greatest (or gradient is highest / most sensitive) between 0 °C and 25 °C (or 16 °C and 17 °C ).

3 marks total (1 mark for ticking C, 1 mark for stating resistance changes the most, 1 mark for identifying the correct temperature range).

💡 Key Knowledge

The normal surface temperature of the sea sits roughly between 0 °C and 25 °C. To measure temperature accurately using a thermistor circuit, you need the component where resistance changes drastically over your target temperature range, providing maximum sensitivity.

❌ Common Errors & Examiner Notes

  • Thermistor A: Rejected because there is little to no change in resistance at sea temperatures.
  • Thermistor B: Rejected because the change in resistance across the temperature range is too small.
  • Thermistor D: Rejected because it has no data available in the required low-temperature range (0 °C to 40 °C).

Topics

Physics · P1: Energy · P2: Electricity

Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Higher), November 2020. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.