Question

Two interfering waves of the same frequency are out of phase but have different amplitudes A₁ and A₂ . What can you say about the intensity of the resultant wave ?

Answer 1

The two interfering waves are out of phase. Thus, the amplitude and hence the intensity of the resultant wave is minimum, I_min ∝ (A _min)² where (A _min)² = (A₁ – A₂ )² .