In Young's double slit experiment, the phase difference between the light waves producing the third bright fringe from the central fringe will be (`lamda=6000` Å)

Options

A. Zero
B. `2pi`
C. `4pi`
D. `6pi`

Answer

D

Explanation

for bright fringes, path difference `=nlamda`
and phase difference`=n(2pi)` where `n=0,1,2`. . .
For the third fringe,n=2
`therefore `Phase difference=`3xx2pi=6pi`