Chapter 25.3, Problem 1aTH

The photograph at right illustrates the pattern that appears on a distant screen when coherent red light is incident on a mask with two identical, very narrow slits. The two slits are separated by a distance d.

Point C marks the center of the screen. Point X marks a point of zero intensity, and points Y and Z mark maxima.

a. In the space at right below the photograph, clearly label each of the lettered points according to $\Delta D$ , the difference in distances from the slits to the point. Express each value of $\Delta D$in terms of λ.