Energy resources and electricity generation questions

Energy resources and electricity generation syllabus

Questions on energy resources and electricity generation can test recall, calculations, explanations, diagrams, data handling and practical skills. You should be able to:

• 4.18P describe the energy transfers involved in generating electricity using: wind water geothermal resources solar heating systems solar cells fossil fuels nuclear power
• 4.19P describe the advantages and disadvantages of methods of large-scale electricity production from various renewable and non-renewable resources

How to answer energy resources and electricity generation questions

1. Identify whether the circuit is series or parallel before combining currents, voltages or resistances.
2. Draw standard circuit symbols cleanly and place ammeters in series and voltmeters in parallel.
3. Show unit conversions, especially milliamps, kilohms, kilowatt-hours and seconds.
4. In explanations, follow charge or energy through the circuit rather than only naming a rule.

Energy resources and electricity generation example questions and worked answers

These examples show how information in a diagram, graph or experimental context becomes part of a complete exam answer.

Example 1: Explaining electricity generation

June 2024 (R) · Paper 2P · Question 6(a)

Question 1

This question is about generating electricity from renewable energy resources.

Photograph 1 shows a solar farm in the United Kingdom and photograph 2 shows a geothermal power station in Iceland.

Discuss the advantages and disadvantages of generating electricity using solar power and geothermal resources.

Final answer

Solar power: An advantage is that it produces no greenhouse gases; a disadvantage is that its output depends on the amount of sunlight.

Geothermal power: An advantage is that it can generate electricity all day; a disadvantage is that it is not available in all locations.

Mark scheme points

1. M1 Solar advantage: no greenhouse, polluting or harmful gases are produced.
2. M2 Solar disadvantage: electricity generation depends on the amount of sunlight.
3. M3 Geothermal advantage: it can be used all day.
4. M4 Geothermal disadvantage: it is not available in all locations.

Explanation

Solar panels generate electricity without producing greenhouse gases, but the amount of electricity they generate depends on sunlight, which varies with the time of day and weather.

Geothermal power uses heat from underground, so it can generate electricity throughout the day. However, suitable geothermal resources are only available in some locations.

Common mistakes

• The examiner report noted that some candidates discussed only solar power or confused geothermal power with a fossil-fuel power station. Give a clearly labelled advantage and disadvantage for each source.
• Do not use “renewable” as an advantage: it is given in the question and is ignored for marks. Statements about cost are also ignored.

Example 2: Plotting wind-turbine voltage measurements

2017 specimen · Paper 1P · Question 6(b)(i)

Question 2

A student investigates a wind turbine.

The student places an electric fan in front of the wind turbine.

The wind turbine is connected to a voltmeter.

When the wind turbine turns, it generates a voltage.

The student obtains the following results.

Blade angle / degree	Voltage / V
0	0.0
10	2.0
20	2.2
30	2.0
40	1.7
50	1.4
60	1.0
70	0.6
80	0.2
90	0.0

Plot the student’s results on the grid.

Final answer

Label the horizontal axis Blade angle / degree and the vertical axis Voltage / V. Use a regular scale that lets the results cover at least half the grid in each direction; for example, 0–100° horizontally and 0–2.5 V vertically. Plot these points accurately:

(0, 0.0), (10, 2.0), (20, 2.2), (30, 2.0), (40, 1.7), (50, 1.4), (60, 1.0), (70, 0.6), (80, 0.2), (90, 0.0).

Mark scheme points

1. M1 Choose a suitable scale so that both axes use at least 50% of the grid.
2. M2 Label both axes with the quantity and its unit.
3. M3 Plot all the results accurately, with each point within 1 mm of its correct position. The axes may be oriented either way.

Explanation

The blade angle is the quantity being changed, so it is plotted against the voltage measured. A scale that makes good use of the grid makes the points easier to place accurately. Check each plotted point against the matching angle and voltage in the results table.

Common mistakes

• Leaving the quantity or unit off either axis label.
• Choosing a scale that uses less than half of the grid along an axis.
• Plotting a voltage against the wrong blade angle, or placing a point inaccurately.

Practise Energy resources and electricity generation questions

Build a focused practice set from this part of the Edexcel IGCSE Physics syllabus.