Chapter 35, Problem 18P

In the two-slit experiment of Fig. 35-10, let angle θ be 20.0°, the slit separation be 4.24 μm, and the wavelength be λ = 500 nm. (a) What multiple of λ gives the phase difference between the waves of rays r₁ and r₂ when they arrive at point P on the distant screen? (c) Determine where in the interference pattern point P lies by giving the maximum or minimum on which it lies, or the maximum and minimum between which it lies.