Types of electromagnetic waves — AQA GCSE Physics
Test yourself on Types of electromagnetic waves with AQA GCSE practice questions.
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Types of electromagnetic waves explained
Electromagnetic waves are oscillating electric and magnetic fields, and the oscillations are perpendicular to the direction of energy transfer, which makes them transverse.
Read the full explanation
Unlike sound they do not need particles, so they travel through a vacuum, which is how energy from the Sun reaches the Earth. Each wave transfers energy from a source to an absorber: the Sun to your skin, a hot grill element to food, a transmitter to an aerial. Nothing material travels from source to absorber, only energy. When the wave is absorbed the energy is transferred to another store, usually the internal energy store of the absorber so its temperature rises, though it can instead produce an alternating current in an aerial or a chemical change in a photographic film.
Your focus
- State two differences between an electromagnetic wave and a sound wave, including the direction of the oscillations.
- Identify the source and the absorber in an everyday example of energy transfer by electromagnetic waves.
- Explain why radiation from the Sun reaches the Earth but the sound of the Sun does not.
Types of electromagnetic waves exam tips
Marking Points
- one mark for stating that the oscillations are perpendicular to the direction of energy transfer
- one mark for saying that electromagnetic waves travel through a vacuum and need no medium
- one mark for naming the source and the absorber in the example given
- one mark for saying that energy, not matter, is transferred from the source to the absorber
Examiner Tips
- 💡Name the source and the absorber explicitly, because questions are usually marked on both.
- 💡Use perpendicular to the direction of energy transfer as your definition of transverse.
- 💡When comparing with sound, pair the points rather than writing two separate lists.
Common Mistakes
- saying electromagnetic waves are longitudinal, or that the oscillations are of particles
- writing that the wave carries energy to the absorber without naming what absorbs it
- claiming electromagnetic waves travel faster in a solid because sound does
- treating light as a stream of particles that are emitted and land on the absorber