Constructive interference occurs when two waves meet:

  1. at right angles
  2. in phase (crest on crest)
  3. in antiphase (crest on trough)
  4. with different frequencies
Answer

B) in phase (crest on crest)

Amplitudes add. SLO P-11-D-08 · Understanding

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