In Young's double slit experiment, when two light waves form third minimum, they have

Options

A. phase difference of `3pi`
B. phase difference of `(5pi)/2`
C. path difference of `3lambda`
D. path difference of `(5lambda)/2`

Answer

D

Explanation

For minima path difference should be an odd multiple of half wavelength
or `Delta=(2n-1)lambda/2`
For third minima `n=3, Delta=(2xx3-1)lambda/2=(5lambda)/2`