Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
The Doppler effect
16 practice questions
Practice questions
1–8 of 8 · Easy
Question 1
1 mark · Easy
Answer and see the solution →State the name given to the apparent change in frequency of a wave caused when either the source or an observer moves relative to the other.
Question 2
2 marks · Easy
Answer and see the solution →Describe how the wavelength of sound waves changes in front of a moving source compared to behind it.
Question 3
1 mark · Easy
Answer and check →Which change will a person hear as a sound source moves towards them?
- A.A higher-pitched sound
- B.A lower-pitched sound
- C.A quieter sound
- D.No change in sound
Question 4
2 marks · Easy
Answer and see the solution →Explain, using the idea of wavefronts, why the pitch of an approaching ambulance siren is higher than when it is stationary.
Question 5
3 marks · Easy
Answer and see the solution →A cyclist is ringing a bell as she moves along a road.
(a)[1 mark]What effect does her motion have on the sound heard by someone in front of her?
(b)[1 mark]What effect does her motion have on the sound heard by someone behind her?
(c)[1 mark]Name the effect described in a) and b).
Question 6
2 marks · Easy
Answer and see the solution →A stationary ambulance travels past a person. While the ambulance moves away, the person notices a change in the siren’s pitch.
(a)[1 mark]Describe what happens to the pitch of the siren as the ambulance moves away.
(b)[1 mark]Explain why this change happens, using wavefronts in your explanation.
Question 7
2 marks · Easy
Answer and see the solution →Why does the Doppler effect happen for both sound and light waves? Give a reason in terms of wave properties.
Question 8
3 marks · Easy
Answer and see the solution →A van is moving while playing music from a speaker attached to its roof.
(a)[2 marks]Describe what would happen to the frequency of the music heard by someone standing in front of the moving van, compared to someone standing behind it.
(b)[1 mark]Explain why this happens.