Young's double slit experiment is carried out using microwaves of
wavelength `lambda=3cm`. Distance between the slits is `d= 5cm` and the distance
between the plane of slits and the screen is `D=100cm`.
(a) Find total number of maxima and
(b) their positions on the screen.

Explanation

(a). The maximum path difference that can be produced =distance between the sources or 5 cm thus in this case we can have only three maximas, one central maxima and two on its either side for a path difference of `lamda` or `3cm`
(b). For maximum intensity at `P,S_(2)P-S_(1)P=lamdaimpliessqrt((lamda+d//2)^(2)+D^(2))-sqrt((y-d//2)^(2)+D^(2))=lamda`
Substituting `d=5cm,D=100cm` and `lamda=3cm` we get `y=+-75`cm
thus the three maximas will be at y=0 and `Y=+-75cm`