Question

If the distance between a minima of order 4 and the central maxima is 172 nm, what is the distance between central maxima and a minima of order 4 in nm?

Answer 1

we know that,

y = m lambda D/d

172 x 10^-9 = 4 lambda (D/d)

lambda(D/d) = 43 x 10^-9

y' = m lambda(D/d) = 4 x 43 x 10^-9 = 172 x 10^-9 m

Hence, y' = 172 nm

Due to Symmetry.