Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
The Electromagnetic Spectrum
70 practice questions
Topics covered
Practice questions
21–30 of 37 · Normal
Question 21
4 marks · Normal
Answer and see the solution →Microwaves are part of the electromagnetic spectrum and have a wide range of applications.
(a)[2 marks]Explain why microwaves are used to send signals to and from satellites, rather than radio waves.
(b)[2 marks]Describe one reason why microwave ovens cook food differently compared to conventional ovens.
Question 22
1 mark · Normal
Answer and see the solution →Which of the following is a detrimental effect of excessive exposure to microwaves in the home?
- A.Can cause burns to human tissue
- B.Causes electric shocks
- C.Can permanently magnetise metals
- D.Can damage bone structure
Question 23
3 marks · Normal
Answer and see the solution →A student is comparing different ways microwaves and radio waves are used in technology. Complete the table below by stating one key use for each wave, and one safety concern linked to each.
Wave Example of a use One safety concern Microwaves Radio waves Question 24
3 marks · Normal
Answer and see the solution →A person spends a long time standing close to a malfunctioning microwave oven that is leaking microwaves.
(a)[2 marks]State and explain one harmful effect this exposure could have on the person’s body.
(b)[1 mark]Suggest one way the design of a microwave oven helps to prevent this effect.
Question 25
2 marks · Normal
Answer and see the solution →A student claims that using mobile phones is completely safe since microwaves have less energy than other waves in the electromagnetic spectrum. Do you agree? Give one scientific reason for your answer.
Question 26
4 marks · Normal
Answer and see the solution →All objects emit infrared radiation. A hot stone is left to cool in a cold room.
(a)[2 marks]Explain why the stone emits more infrared radiation as its temperature increases.
(b)[2 marks]Name two household appliances or devices that use infrared radiation for their operation.
Question 27
2 marks · Normal
Answer and see the solution →State two uses of infrared radiation other than for heating.
Question 28
3 marks · Normal
Answer and see the solution →Special cameras designed to detect infrared waves can be used to find people in darkness, such as in a rescue operation after a building collapse. Infrared images show hot bodies as white shapes against a dark background.
(a)[3 marks]Explain why infrared cameras are useful for finding people in such situations.
Question 29
3 marks · Normal
Answer and see the solution →A metal plate is heated by an infrared lamp. The initial temperature of the plate is , and it rises to after 3 minutes of heating.
(a)[2 marks]Describe, using ideas about infrared radiation, why the temperature of the plate increases when placed under the lamp.
(b)[1 mark]State an effect of increasing the power of the lamp on the rate at which the plate heats up.
Question 30
4 marks · Normal
Answer and see the solution →A remote control uses infrared radiation to operate a television.
(a)[2 marks]State why infrared is suitable for this use rather than visible light.
(b)[2 marks]Suggest why remote controls do not work well when something is placed in front of the TV's infrared sensor.