Each piano key in the middle range has two or three strings. A 'chorus' or 'wavering' sound occurs when:

  1. the key is not pressed
  2. these strings are slightly out of tune, producing beats
  3. they are perfectly in tune
  4. the piano is in a vacuum
Answer

B) these strings are slightly out of tune, producing beats

Small frequency differences. SLO P-11-D-16 · Application

Physics MCQ · More Superposition, Stationary Waves and Beats MCQs · Practise