Question

What is the conditions for obtaining good interference pattern. At a point on the two slit interference pattern obtained using a source of given wavelength 5300 A0 the path difference is 4.125 m is the point at the centre bright or dark fringe? Hence, find the order of the fringe?​

Answer 1

Explanation:

Data: Path difference,

Δ=4.2×10−6m,λ=6000Å=6×10−7m

Let p be an integer such that p(λ2)=Δ.

∴p=2Δλ=2×4.2×10−66×10−7=8.4×106

=846=14

Since p is an even integer, the point must be bright.