Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
Infrared
16 practice questions
Practice questions
11–16 of 16
Question 11
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 12
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 13
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.
Question 14
1 mark · Normal
Answer and check →Which statement about infrared radiation is correct?
- A.All objects emit infrared radiation, but only hot objects emit visible light.
- B.Cold objects emit more infrared radiation than hot objects.
- C.Infrared radiation cannot be detected by any cameras.
- D.Infrared radiation passes easily through all objects.
Question 15
4 marks · Normal
Answer and see the solution →Describe an experiment you could perform to compare how different surfaces (e.g. shiny metal vs. matt black) emit infrared radiation when heated.
Question 16
3 marks · Normal
Answer and see the solution →Explain why infrared radiation from the Sun is able to warm the Earth's surface, even though the Earth's atmosphere is mostly transparent to visible light.