Two in phase coherent sources emitting harmonic waves of wavelength λ are separated by a distance d. What is the minimum value of d for which destructive interference occurs everywhere along the line that passes through the locations of the two sources?
A)λ/2
B)λ
C)zero
D)2λ
E)λ/4

Question

Quizplus · Accepted Answer

For destructive interference to occur everywhere along the line, the path difference between the waves from the two sources must be λ/2. Therefore, the minimum separation distance d between the sources should be λ/2.

Two in Phase Coherent Sources Emitting Harmonic Waves of Wavelength