Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Waves
356 practice questions
Topics covered
Practice questions
131–140 of 181 · Normal
Question 131
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 132
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 133
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 134
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 135
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.
Question 136
4 marks · Normal
Answer and see the solution →The electromagnetic spectrum includes waves with a wide range of wavelengths and frequencies.
(a)[1 mark]State the relationship between wavelength and frequency for electromagnetic waves.
(b)[2 marks]Arrange the following electromagnetic waves in order of increasing wavelength: infrared, gamma rays, microwaves, visible light.
(c)[1 mark]Why do gamma rays have a higher frequency than microwaves? Explain in terms of energy.
Question 137
5 marks · Normal
Answer and see the solution →A communication satellite receives signals using microwaves and sends back information using infrared waves.
(a)[1 mark]State the order of infrared and microwaves in the electromagnetic spectrum in terms of wavelength, starting with the longest.
(b)[2 marks]Explain why microwaves are suitable for transmitting signals to and from the satellite compared to visible light.
(c)[2 marks]Give one possible health effect of excessive exposure to microwaves and state a precaution to reduce the risk.
Question 138
4 marks · Normal
Answer and see the solution →A teacher shines visible red light (wavelength m) and uses a microwave oven that emits microwaves of wavelength m.
(a)[2 marks]Calculate the frequency of the red light. Take the speed of light in a vacuum as m/s.
(b)[2 marks]Calculate the frequency of the microwave.
Question 139
4 marks · Normal
Answer and see the solution →A hospital uses both X-rays and infrared cameras for patient care.
(a)[1 mark]State the main property that all electromagnetic waves have in common.
(b)[2 marks]Describe one use of infrared in hospitals, and one use of X-rays.
(c)[1 mark]Explain why X-rays require more safety precautions than infrared when used with patients.
Question 140
1 mark · Normal
Answer and see the solution →State whether light waves are transverse or longitudinal.