Two beams of coherent light travel different paths arriving at point P. If the maximum constructive interference is to occur at point P, the two beams must
A) arrive 180° out of phase.
B) arrive 90° out of phase.
C) travel paths that differ by an odd number of half-wavelengths.
D) travel paths that differ by a whole number of wavelengths.

Question

Quizplus · Accepted Answer

For maximum constructive interference to occur at point P, the two beams of coherent light must arrive in phase or have a phase difference that corresponds to a whole number of wavelengths. This ensures that the peaks of one wave align with the peaks of the other wave, and the troughs align as well, leading to constructive interference where the amplitude of the resultant wave is maximized.

Two Beams of Coherent Light Travel Different Paths Arriving at Point