When two slits are replaced with three slits (with the same slit-to-slit spacing), all of the following changes occur in the interference fringe pattern except
A) the angular separation between principal maxima and the adjacent points of minima is reduced.
B) it is no longer dark at the points where the two-slit minima were located.
C) the principal maxima are more closely spaced.
D) the principal maxima are brighter.

Question

Quizplus · Accepted Answer

When three slits are used instead of two, with the same slit-to-slit spacing, the angular separation between principal maxima does not change; it remains determined by the slit-to-slit spacing. What changes is the intensity and the distribution of the maxima and minima, leading to brighter principal maxima and the appearance of additional points of minima and maxima.

When Two Slits Are Replaced with Three Slits (With the Same