In the Young’s double slit experiment, the resultant intensity at a point on the screen is 75% of the maximum intensity of the bright fringe. Then the phase difference between the two interfering rays at that point is

Options

A. `pi/6`
B. `pi/4`
C. `pi/3`
D. `pi/2`

Answer

c

Explanation

The phase difference between the two interfering rays is,
`implies ¾ (4a^(2))=3a^(2)`
`implies4a^(2)cos^(2) phi/2=3a^(2) [ because cos^(2)(phi/2)=3/4]`
`impliescos^(2)(phi/2)=3/4`
`impliesphi/2 = cos^(-1)(sqrt(3)/2)= pi/6`
`implies phi= pi/3`