The Doppler effect
1 mark · NormalWhich 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.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
Correct option: The change in frequency of a wave observed when the source is moving relative to the observer.
Common mistakes: Choosing reflection or diffraction instead of Doppler effect.
Show mark scheme and worked solution
Marking points
B1 · 1 mark · Correct option selected.
Worked solution
A is correct: The Doppler effect is the observed change in frequency (and wavelength) when the source is moving relative to the observer.