Electromagnetic waves form a continuous spectrum. Describe the electromagnetic spectrum, including the properties shared by all electromagnetic waves and how the waves differ from one another.

Eduqas A-Level Physics — 6.2 Particle physics and the standard model (A-Level only) · Describe · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (5 marks)

All electromagnetic waves are transverse waves.
They all travel at the same speed in a vacuum, 3 × 10⁸ m/s.
They differ in frequency (and therefore wavelength and energy).
Gamma rays have the highest frequency, while radio waves have the lowest.
Electromagnetic waves transfer energy from the source to the absorber.

Examiner tips

  • Use the word "transverse" and the speed 3×10⁸ m/s. Mention frequency, wavelength and energy as the varying properties. State the extremes: gamma rays (high) and radio waves (low).
  • Show the energy transfer point to cover all criteria.

Common mistakes

  • Confusing longitudinal with transverse. Forgetting the speed in a vacuum. Omitting the energy transfer aspect.

Mark scheme (5 marks)

  1. All electromagnetic waves are transverse waves
  2. All electromagnetic waves travel at the same speed in a vacuum (3 × 10⁸ m/s)
  3. The waves differ in frequency (and wavelength / energy)
  4. Gamma rays have the highest frequency (and radio waves have the lowest frequency) in the spectrum
  5. Electromagnetic waves transfer energy from source to absorber

Key terms in this question

electromagnetic spectrum

Related

More Particle physics and the standard model (A-Level only) questions

▶ Try answering this question with AI marking (free) →