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

Question

Quizplus · Accepted Answer

For constructive interference to occur everywhere along the line, the path difference between the waves from the two sources must be an integer multiple of the wavelength. The minimum non-zero separation that satisfies this condition is one wavelength, λ.

Two in Phase Coherent Sources Emitting Harmonic Waves of Wavelength