lamda = 469 nm
= 469*10^-9 m
d = 2.1*10^-6 m
a) for dark fringe m = 0
path difference, d*sin(theta) = lamda/2
sin(theta) = lamda/(2*d)
= 469*10^-9/(2*2.1*10^-6)
= 0.1117
theta = sin^-1(0.1117)
= 6.41 degrees
<<<<<<<<<<<-----------------Answer
b) for bright fringe m = 1
path difference, d*sin(theta) = 1*lamda
sin(theta) = lamda/(d)
= 469*10^-9/(2.1*10^-6)
= 0.223
theta = sin^-1(0.223)
= 12.9 degrees
<<<<<<<<<<<-----------------Answer
c) for dark fringe m = 1
path difference, d*sin(theta) = 3*lamda/2
sin(theta) = 3*lamda/(2*d)
= 3*469*10^-9/(2*2.1*10^-6)
= 0.335
theta = sin^-1(0.335)
= 19.6 degrees
<<<<<<<<<<<-----------------Answer
d) for bright fringe m = 2
path difference, d*sin(theta) = 2*lamda
sin(theta) = 2*lamda/(d)
= 2*469*10^-9/(2.1*10^-6)
= 0.447
theta = sin^-1(0.447)
= 26.6 degrees
<<<<<<<<<<<-----------------Answer
