AQA GCSE Physics Physics Paper 1 (Foundation), June 2022: Question 9
9 marks · Standard Demand difficulty · Short Answer
Calculate the mean power needed for 1 home, suggest why wind power could not meet national demand, explain the effect of oiling on wind turbine efficiency, and explain the benefits of using energy efficient electrical devices.
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Question text
09 Figure 13 shows a large wind farm off the coast of the UK.
Figure 13
The mean power output of the wind farm is 696 MW, which is enough power for
580000 homes.
09.1 Calculate the mean power needed for 1 home.
Give your answer in watts.
[2 marks]
Mean power needed for 1 home =31 W
09.2 On one day the demand for electricity in the UK was 34000 MW.
Suggest two reasons why wind power was not able to meet this demand.
[2 marks]
09.3 Some of the energy from the wind used to rotate a wind turbine is wasted.
An engineer oils the mechanical parts of a wind turbine.
Explain how oiling would affect the efficiency of the wind turbine.
[3 marks]
09.4 In most homes in the UK there are many different electrical devices.
Explain why people should be encouraged to use energy efficient electrical devices.
[2 marks]
Mark scheme
Show the mark scheme
Question 9
AO /
Question Answers Extra information Mark
Spec. Ref.
09.1 P = 696 000 000 (W) 1 AO2
4.1.3
P = 1200 (W) allow an answer consistent with 1
their incorrectly / not converted
value of P
AO /
Spec. Ref.
09.2 any 2 from: 2 AO2
• wind is unreliable allow it was not windy (on that 4.1.3
day)
• wind turbines don’t turn when
the wind is too strong/weak
• there are not enough wind
turbines (in the UK)
allow some wind turbines may
be offline for maintenance
allow energy from wind may not
be enough (to generate 34 000
MW)
ignore weather conditions
unqualified
AO /
Spec. Ref.
the efficiency would increase 1 AO3
09.3
because the percentage / ignore more electricity 1 AO1
proportion / amount of energy generated
usefully transferred would
increase
or
because the percentage / allow less energy wasted
proportion / amount of energy
wasted would decrease
AO1
(because) less (work is done – HYSICS – 1 – 4.1.2.1
against) friction 4.1.2.2
24 AO /
Spec. Ref.
09.4 more efficient devices waste ignore use less electricity 1 AO3
less energy 4.1.2.2
or 4.1.3
more efficient devices need a
lower energy input (for the same
energy output)
which would minimise the allow less electricity needs to be 1
electricity / energy demand generated
allow lower energy / electricity
bill
or
which would minimise the allow examples of
environmental impact from environmental impact
(fossil fuel) electricity generation e.g. lower CO2 emissions
ignore ‘better for the
environment’ unless qualified
ignore answers that discuss
‘saving energy’ unless qualified
ignore answers that discuss
alternative methods of
generating electricity
Total Question 9 9
How to answer it
Energy Resources, Efficiency, and Power Calculations
What this question tests
This question assesses your understanding of renewable energy resources (wind power), unit conversions (megawatts to watts), efficiency principles, reduction of wasted energy through lubrication, and the environmental/economic benefits of energy-efficient appliances.
Calculating Power Output per Home
✅ Correct Answer
696 000 000 W (or 6.96 × 10⁸ W ) for the converted total power, and 1200 W for the final answer.
📐 Step-by-Step Calculation
- Convert Mega- to base units: 696 MW = 696,000,000 W (multiply by 1,000,000).
- Divide by the number of homes: 696,000,000 W ÷ 580,000 homes = 1200 W.
❌ Common Errors
Forgetting to convert megawatts (MW) into watts (W) will result in losing the first mark. Double-check your zeros!
Limitations of Wind Power
✅ Correct Answer (Any two)
- Wind is unreliable / it was not windy on that day.
- Wind turbines do not turn when the wind is too strong or too weak.
- There are not enough wind turbines in the UK to generate 34,000 MW.
- Some wind turbines may be offline for maintenance.
🧠 Exam Technique
Be specific. Examiners reject vague answers like "weather conditions" unless qualified by wind speed or lack of wind.
Lubrication and Efficiency
✅ Correct Answer
The efficiency would increase because less energy is wasted due to less work being done against friction (or a higher proportion of energy is usefully transferred).
💡 Key Knowledge
Friction between moving mechanical parts causes thermal energy to be dissipated to the surroundings (wasted). Adding a lubricant reduces frictional forces, meaning less input energy is wasted as heat.
❌ Common Errors
Do not state that oiling "generates more electricity". Turbines only convert the kinetic energy available from the wind; efficiency describes how well that input energy is transferred without being wasted.
Energy-Efficient Appliances
✅ Correct Answer
More efficient devices waste less energy / need a lower energy input, which minimises electricity demand and reduces environmental impact (e.g., fewer greenhouse gas emissions from fossil fuels).
🧠 Exam Technique
Avoid generic phrases like "better for the environment" or "saving energy" unless you qualify them. Explain how it helps—such as requiring less electricity to be generated or lowering CO₂ emissions.
Topics
Physics · P1: Energy
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Foundation), June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.