Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
The Doppler effect
16 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →State what happens to the frequency of sound waves from a moving source as it moves towards a stationary observer. Explain your answer.
Question 2
3 marks · Normal
Answer and see the solution →The speed of sound in a material is 1500 m/s. Calculate the frequency of a sound wave in this material if its wavelength is 2.0 m. Give your answer to 2 significant figures.
Question 3
3 marks · Normal
Answer and see the solution →A stationary ambulance is sounding its siren at a constant frequency. Describe and explain what happens to the pitch of the siren for an observer as the ambulance starts to move away from them.
Question 4
1 mark · Normal
Answer and see the solution →Which one of the following statements best describes the Doppler effect?
- A.The change in frequency of a wave observed when the source is moving relative to the observer.
- B.The reflection of waves from a hard surface.
- C.The bending of waves when they pass through a gap.
- D.The decrease in energy of a wave as it moves further from the source.
Question 5
3 marks · Normal
Answer and see the solution →Explain why the frequency of a siren heard by a person changes when a fire engine moves past them at a constant speed.
Question 6
4 marks · Normal
Answer and see the solution →A student observes a train moving towards a platform while sounding its horn.
(a)[1 mark]Describe what happens to the frequency of the sound heard by a person standing on the platform as the train approaches.
(b)[2 marks]Explain your answer to part (a).
(c)[1 mark]What will happen to the frequency of the sound as the train passes and moves away from the platform?
Question 7
3 marks · Normal
Answer and see the solution →Describe a simple experiment you could carry out to demonstrate the Doppler effect for sound. Explain what you would expect to observe.
Question 8
3 marks · Normal
Answer and see the solution →A car is moving at a high speed with its horn sounding. Compare what an observer in front of the car hears to what an observer behind the car hears. Explain your answer.