Chapter 25.3, Problem 1bTH

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.

b. Suppose that the two−slit mask were replaced by a mask with five slits of the same width as the original slits, with adjacent slits separated by the same distance as before.

1. Would point X still be a point of zero intensity with the five−slit mask? Explain your reasoning.
2. Would point C, the center of the screen, still be a point of maximum constructive interference with the five−slit mask? Explain your reasoning.
3. With the five−slit mask, how many minima would there be between each pair of principal maxima?
   
4. Would point Z still be a point of maximum constructive interference with the five−slit mask? Explain your reasoning.
5. If the distance between the centers of adjacent slits in the five−slit mask is 125?, determine the angle (measured relative to the normal to the screen) to the minimum closest to the center of the screen. Show your work.