Wavelength: GCSE Physics Definition

Leander Oates

Written by: Leander Oates

Published

Read time

2 minutes

What is wavelength?

In GCSE physics, wavelength is a property of a wave that describes the distance between one point on a wave to the same point on the next wave. Wavelength can be measured from any point on the wave, as long as the same point is used on the following wave. 

In a transverse wave, wavelength can be measured from peak to peak or from trough to trough. In a longitudinal wave, wavelength can be measured from the centre of one compression (or rarefaction) to the centre of the next.

Diagram showing transverse and longitudinal waves. Transverse wave with peaks and troughs, longitudinal wave with compressions and rarefactions, both labelled.
An example of how the wavelength can be measured on a transverse and longitudinal wave

The wavelength of a wave can be calculated using the wave equation in the following form:

lambda equals v over f

Where:

  • lambda= wavelength, measured in metres (m)

  • v = wave speed, measured in metres per second (m/s)

  • f = frequency, measured in hertz (Hz)

The wavelength of a wave is inversely proportional to the frequency of the wave. 

lambda proportional to 1 over f

Therefore, the longer the wavelength, the lower the frequency, and the shorter the wavelength, the higher the frequency.

Diagram of the electromagnetic spectrum showing waves from low energy radio waves to high energy gamma rays, with visible light in the centre.
Waves with a longer wavelength have a lower frequency, and waves with a shorter wavelength have a higher frequency

Wavelength revision resources to ace your exams

You can strengthen your understanding of wavelength by using our revision notes tailored specifically for the AQA, Edexcel, OCR, and WJEC exam boards.

You can practice wavelength questions and calculations with helpful guidance and examiner tips using our exam board specific GCSE Physics exam questions

Explore Our GCSE Physics Revision Resources

Sign up for articles sent directly to your inbox

Receive news, articles and guides directly from our team of experts.

Share this article

Leander Oates

Author: Leander Oates

Expertise: Physics

Leander graduated with First-class honours in Science and Education from Sheffield Hallam University. She won the prestigious Lord Robert Winston Solomon Lipson Prize in recognition of her dedication to science and teaching excellence. After teaching and tutoring both science and maths students, Leander now brings this passion for helping young people reach their potential to her work at SME.

The examiner written revision resources that improve your grades 2x.

Join now