Two separated sources emit sinusoidal traveling waves that have the same wavelength $\lambda$ and are in phase at their respective sources.One travels a distance $\lambda$₁ to get to the observation point while the other travels a distance $\lambda$₂.The amplitude is a minimum at the observation point if $\lambda$₁$\lambda$ ₂ is: A)an odd multiple of $\lambda$ /2 B)an odd multiple of $\lambda$ /4 C)a multiple of $\lambda$ . D)an odd multiple of $\lambda$ /2. E)a multiple of $\pi$

Question

Quizplus · Accepted Answer

When the two waves meet at the observation point, the amplitude will be minimum if they are in opposite phase (i.e. one is at its peak while the other is at its trough). The phase difference between the two waves can be calculated using the path difference between them. If the path difference is an odd multiple of half the wavelength, then the waves will be in opposite phase. Therefore, the path difference ℓ₁ - ℓ₂ must be an odd multiple of F1F1F1S1λF1F1F10/2, which is choice A.

Two Separated Sources Emit Sinusoidal Traveling Waves That Have the Same