The path difference between two interfering waves of equal intensities at a point on the screen is `lambda//4`. The ratio of intensity at this point and that at the central fringe will be

Options

A. `1`
B. `0.5`
C. `1.5`
D. `2.0`

Answer

B

Explanation

From `I_(R)=I_(1)+I_(2)+2sqrt(I_(1)I_(2))cosphi`
where, `phi=(2pi)/(lambda)xx(lambda)/(4)=(pi)/(2)`
`I_(R)=I+I+2Icos.(pi)/(2)=2I`
At the central bright fringe, `I._(R)=4I`
`:.(I_(R))/(I_(R))=(2I)/(4I)=0.5`