What does the WJEC generating electricity and energy content cover?

It draws together Unit 1 topics 1.2 (generating electricity) and 1.3 (making use of energy). It covers renewable and non-renewable energy resources, how power stations work, the National Grid and step-up and step-down transformers, energy stores and transfers, the conservation of energy and efficiency, the three ways heat is transferred, and reducing heat loss from buildings.

Which ideas and equations do I need for this content?

Know the energy stores and pathways, conservation of energy, the efficiency equation (useful output over total input), the power equation (power equals voltage times current) and the transmission loss idea (power lost equals current squared times resistance), and payback time (cost over annual saving). The power equations appear on the WJEC formula list.

Why is electricity transmitted at high voltage?

Transmitting at a high voltage allows the same power to be carried at a low current. Because the energy wasted as heat in the cables is proportional to the current squared times the resistance, a low current wastes far less energy, making long-distance transmission efficient. Transformers step the voltage up for transmission and down for safe use.

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WJEC GCSE Physics generating electricity and energy overview

Q: How is this content examined?

It sits in Unit 1 (Electricity, Energy and Waves), a 1 hour 45 minute written paper worth 80 marks and 45% of the GCSE. Expect energy-transfer descriptions, efficiency and payback calculations, comparisons of energy resources, explanations of high-voltage transmission, and questions on conduction, convection, radiation and insulation.

An overview of the generating electricity and energy content in Unit 1 of WJEC GCSE Physics (3420), mapping energy resources and power stations, the National Grid and transformers, energy transfer and efficiency, and reducing energy loss in the home, with the key ideas and how the topics are examined.

Generated by Claude Opus 4.88 min readWJEC 3420 Unit 1.2, 1.3Updated 2026-06-14

Reviewed by: AI editorial process; not yet individually human-reviewed

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The content
How this content is examined
How to study it
For the official specification

The generating electricity and energy content of WJEC GCSE Physics (specification 3420) brings together topics 1.2 and 1.3 of Unit 1. It is about where electricity comes from, how it is transmitted efficiently, and how energy is transferred, wasted and conserved in the home. It is examined in Unit 1 (Electricity, Energy and Waves). This page maps the content and links to a focused answer page for each part.

The content

Energy resources and power stations (1.2): Renewable and non-renewable resources, how a power station generates electricity, and comparing resources. See Energy resources and power stations.
The National Grid and transformers (1.2): The grid, step-up and step-down transformers, and why high-voltage transmission reduces losses. See The National Grid and transformers.
Energy transfer and efficiency (1.3): Energy stores and transfers, conservation of energy, wasted energy, and efficiency. See Energy transfer and efficiency.
Reducing energy loss in the home (1.3): Conduction, convection and radiation, heat loss, insulation, and cost-effectiveness using payback time. See Reducing energy loss in the home.

How this content is examined

This content sits in Unit 1, a written paper of 1 hour 45 minutes, worth 80 marks and 45% of the GCSE, tiered into Foundation and Higher. Expect energy-transfer descriptions, efficiency and payback calculations, comparisons of energy resources, explanations of high-voltage transmission and transformers, and questions on the three ways heat is transferred and on insulation.

How to study it

Sort the resources. Know which are renewable and non-renewable and one advantage and disadvantage of each.
Tell the transmission story. High voltage means low current, and low current means small $I^2R$ losses.
Practise efficiency and payback. Useful over total for efficiency; cost over annual saving for payback time.
Separate the heat transfers. Conduction in solids, convection in fluids, radiation through a vacuum.
Link to insulation. Trapped air is a poor conductor and limits convection.

For the official specification

WJEC publishes the full specification, past papers and mark schemes at wjec.co.uk. Always revise from the current specification and WJEC's own past papers, because question style, tiering and the formula list are board-specific.

Sources & how we know this

WJEC GCSE Physics specification (3420) from 2016 — WJEC (2016)