Consider the arrangement shown in figure (17-E7). By some mechanism, the separation between the slits S3 and S4 can be changed . the intensity is measured at the point P which is at the common perpendicular bisector of S1S2 andS3S4 When z = dλ2d, the intensity measured at P is I. Find this intensity when z is equal to (a) Dλd, (b) 3Dλ2d and (c) 2Dλd.

Consider the arrangement shown in figure (17-E7). By some mechanism, t

1.	Consider the arrangement shown in figure (17-E7). By some mechanism, the separation between the slits S3 and S4 can be changed . the intensity is measured at the point P which is at the common perpendicular bisector of S1S2 andS3S4 When z = dλ2d, the intensity measured at P is I. Find this intensity when z is equal to (a) Dλd, (b) 3Dλ2d and (c) 2Dλd.
Answer» Consider the arrangement shown in figure (17-E7). By some mechanism, the separation between the slits $S_{3}$ and $S_{4}$ can be changed . the intensity is measured at the point P which is at the common perpendicular bisector of $S_{1} S_{2}$ and $S_{3} S_{4}$ When z = $\frac{d λ}{2 d},$ the intensity measured at P is I. Find this intensity when z is equal to (a) $\frac{D λ}{d}$ , (b) $\frac{3 D λ}{2 d}$ and (c) $\frac{2 D λ}{d} .$