What does the WJEC waves content cover?

It draws together Unit 1 topics 1.5 (features of waves), 1.6 (total internal reflection of waves) and 1.7 (seismic waves). It covers transverse and longitudinal waves, amplitude, wavelength, frequency, period and the wave equation, the electromagnetic spectrum and its uses and hazards, reflection, refraction, the critical angle, total internal reflection and optical fibres, and P-waves and S-waves and what they reveal about the Earth.

Which equations do I need for the waves content?

The main equations are the wave equation (wave speed equals frequency times wavelength) and the relationship between frequency and period (frequency equals one over the period). These appear on the WJEC formula list, and Higher candidates must rearrange them.

Which practicals appear in the waves content?

Investigating waves in a ripple tank or on a string to measure frequency, wavelength and speed, and investigating the reflection and refraction of light, including measuring angles and finding a critical angle. These can be assessed in Unit 3 and sampled in the written papers.

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WJEC GCSE Physics waves overview

Q: How is the waves 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 wave equation calculations, ordering and uses and hazards of the electromagnetic spectrum, ray diagrams and refraction explanations, total internal reflection and optical fibre questions, and seismic wave and Earth-structure reasoning.

An overview of the waves content in Unit 1 of WJEC GCSE Physics (3420), mapping the features of waves, the electromagnetic spectrum, reflection, refraction and total internal reflection, and seismic waves, with the wave equation and how the topics are examined.

Generated by Claude Opus 4.88 min readWJEC 3420 Unit 1.5, 1.6, 1.7Updated 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 waves content of WJEC GCSE Physics (specification 3420) brings together topics 1.5, 1.6 and 1.7 of Unit 1. It is about how waves are described and measured, the electromagnetic spectrum and its uses and hazards, how light reflects and refracts, and how seismic waves reveal the inside of the Earth. 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

Features of waves (1.5): Transverse and longitudinal waves, amplitude, wavelength, frequency and period, and the wave equation. See Features of waves.
The electromagnetic spectrum (1.5): The order from radio to gamma, the shared properties of EM waves, and the uses and hazards of each region. See The electromagnetic spectrum.
Reflection, refraction and total internal reflection (1.6): The law of reflection, refraction at a boundary, the critical angle, total internal reflection and optical fibres. See Reflection, refraction and total internal reflection.
Seismic waves (1.7): P-waves and S-waves, how they travel through the Earth, the shadow zones, and the evidence for a layered structure. See Seismic waves.

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 wave equation calculations, ordering and uses and hazards of the electromagnetic spectrum, ray diagrams and refraction explanations, total internal reflection and optical fibre questions, and seismic wave reasoning about the Earth's structure.

How to study it

Master the wave equation. Practise $v = f\lambda$ and $f = \dfrac{1}{T}$ until selecting and rearranging them is automatic.
Learn the spectrum in order. Radio to gamma, with one use and one hazard for each region.
Draw rays from the normal. Reflection and refraction angles are always measured from the normal.
Nail the TIR conditions. Denser medium and an angle above the critical angle, as used in optical fibres.
Read seismic evidence. S-waves blocked by the liquid outer core, P-waves refracting, building the layered model.

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)