Chapter 35, Problem 84P

GO In Figure 35-50, two isotropic point sources S₁ and S₂ emit light in phase at wavelength λ and at the same amplitude. The sources are separated by distance d = 6.00 λ on an x axis. A viewing screen is at distance D = 20.0 λ from S₂ and parallel to the y axis. The figure shows two rays reaching point P on the screen, at height y_P. (a) At what value of y_P do the rays have the minimum possible phase difference? (b) What multiple of λ gives that minimum phase difference? (c) At what value of y_P do the rays have the maximum possible phase difference? What multiple of λ gives (d) that maximum phase difference and (e) the phase difference when y_P = d? (f) When y_P = d, is the resulting intensity at point P maximum, minimum, intermediate but closer to maximum, or intermediate but closer to minimum?

Figure 35-50 Problem 84.