Uses of Electromagnetic Waves
Understand Uses of Electromagnetic Waves for GCSE Physics with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Each part of the electromagnetic spectrum has uses matched to its properties, from radio broadcasting to medical imaging.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Different types of electromagnetic wave are used for different purposes, and in each case the use follows from the properties of that wave.
Radio waves are used for television and radio broadcasting. Microwaves are used for satellite communications and cooking food. Infrared is used for electrical heaters, cooking food and infrared cameras.
Visible light is used for fibre optic communications. Ultraviolet is used for energy efficient lamps and sun tanning. X-rays and gamma rays are used in medicine for internal imaging and for treating cancer. Questions usually ask you to link the use to the property, so learning both together matters.
Revision notes
Radio, microwave and infrared
Radio waves: television and radio broadcasting, because they can travel long distances and are not strongly absorbed by the atmosphere.
Microwaves: satellite communications, because they pass through the atmosphere, and cooking food because they are absorbed by water molecules. Infrared: electrical heaters, cooking, and infrared cameras.
Visible and ultraviolet
Visible light: fibre optic communications, because it can be transmitted along a glass fibre by repeated internal reflection.
Ultraviolet: energy efficient lamps and sun tanning. It carries more energy than visible light, which is why it can cause tanning and burning.
X-rays and gamma rays
X-rays: medical imaging of bones, because they pass through flesh but are absorbed by denser bone.
Gamma rays: sterilising medical equipment and treating cancer, because they carry enough energy to kill cells.
Key points
- Radio waves are used for broadcasting.
- Microwaves are used for satellite communications and cooking.
- Infrared is used for heaters and cameras.
- Visible light is used in fibre optic communications.
- X-rays are used for medical imaging.
- Gamma rays are used to treat cancer.
Worked examples
Example 1
State one use of microwaves and explain why they are suitable. [2 marks]
Model answer
Satellite communications (1 mark), because microwaves can pass through the Earth's atmosphere to reach a satellite and return (1 mark).
Example 2
Explain why X-rays are used for medical imaging of bones. [2 marks]
Model answer
X-rays pass through flesh but are absorbed by denser material such as bone (1 mark), so the bones show as a shadow on the image (1 mark).
Example 3
State two uses of infrared radiation. [2 marks]
Model answer
Electrical heaters or cooking food (1 mark). Infrared cameras for detecting heat (1 mark).
Common mistakes
Naming a use without the property.
Questions usually want the use linked to why that wave is suitable.
Confusing microwave and infrared cooking.
Microwaves are absorbed by water molecules throughout the food; infrared heats the surface.
Saying visible light is used for X-ray imaging.
X-rays are needed because they penetrate flesh.
Mixing up ultraviolet and infrared uses.
UV is for tanning and energy efficient lamps; infrared is for heating.
Exam tips
- Learn each use paired with the property that makes it work.
- Give a specific example rather than a general category.
- Keep infrared and microwave uses distinct.
- Match the energy of the wave to the application.
Key terms
- Fibre optic
- Communication using visible light in glass fibres.
- Satellite communication
- Using microwaves to reach and return from a satellite.
- Medical imaging
- Using X-rays to see inside the body.
- Sterilisation
- Using gamma rays to kill microbes.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.