Chapter 35, Problem 5Q

Is there an interference maximum, a minimum, an intermediate state closer to a maximum, or an intermediate state closer to a minimum at point P in Fig. 35-10 if the path length difference of the two rays is (a) 2.2λ, (b) 3.5λ, (c) 1.8λ, and (d) 1.0λ? For each situation, give the value of m associated with the maximum or minimum involved.

Figure 35-10 (a) Waves from slits, S₁ and S₂ (which extend into and out of the page) combine at P, an arbitrary point on screen C at distance y from the central axis. The angel θ serves as a convenient locator for P. (b) For D > d, we can approximate rays r₁ and r₂ as begin parallel, at angel θ to the central axis