AQA GCSE PHYSICS · PAPER 2 · FOUNDATION & HIGHER
Exam Practice: Uses of electromagnetic waves
Uses of electromagnetic waves · Waves · Lesson 9 of 12 · 15 marks · 16 minutes
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Instructions
• Answer all the questions.
• Write your answers in the spaces provided.
• The marks for each question are shown in brackets - use this as a guide to how much to write.
• The answers are on separate pages at the back. Attempt every question before you look at them.
• Answer all questions. Use the mark allocation as a guide to how much to write.
Question 1 STATE (3 marks)
Give one use for each of the following types of electromagnetic wave: (a) radio waves (b) microwaves (c) X-rays.
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(Total for Question 1 = 3 marks)
Question 2 EXPLAIN (3 marks)
Explain why microwaves are used for satellite communications.
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(Total for Question 2 = 3 marks)
Question 3 EXPLAIN (3 marks)
X-rays are used to produce images of broken bones. Explain why X-rays are suitable for this use.
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(Total for Question 3 = 3 marks)
Question 4 EXPLAIN (4 marks)
Explain why gamma rays can be used both to treat cancer and to sterilise medical equipment, and why care is needed when they are used.
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(Total for Question 4 = 4 marks)
Question 5 STATE (2 marks)
Give two uses of infrared radiation.
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(Total for Question 5 = 2 marks)
TOTAL FOR PAPER = 15 MARKS
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Answers and mark scheme
Check your answer only once you have written one.
Question 1 (3 marks)
(a) Television or radio. (b) Satellite communications or cooking. (c) Medical imaging.
• Radio waves use 1 mark
• Microwaves use 1 mark
• X-rays use 1 mark
Question 2 (3 marks)
Microwaves can pass through the Earth's atmosphere to the satellite and back without being absorbed or reflected much, and can be sent in narrow beams.
• Pass through the atmosphere 1 mark
• Not absorbed or reflected much 1 mark
• Reach the satellite and return 1 mark
Question 3 (3 marks)
Soft tissue transmits X-rays but bone absorbs them. Bones therefore show up on the detector as a shadow.
• Transmitted by soft tissue 1 mark
• Absorbed by bone 1 mark
• Image shows bone 1 mark
Question 4 (4 marks)
Gamma rays are penetrating and ionising, so they can kill cancer cells and bacteria. Because they can also damage healthy cells and cause mutations, exposure must be limited and shielding used.
• Penetrating or high energy 1 mark
• Ionising: kills cells or bacteria 1 mark
• Also damages healthy cells 1 mark
• So precautions needed 1 mark
Question 5 (2 marks)
Any two from: electrical heaters, cooking food, infrared cameras, remote controls.
• First use 1 mark
• Second use 1 mark