The path of difference between two interfering waves at a point on the screen is `(lambda)/(8)` . The ratio of intensity at this point and that at the central fringe will be :

Options

A. 0.853
B. 8.53
C. 85.3
D. 853

Answer

A

Explanation

Phase differecne `= (2 pi)/(lambda)` (Path difference)
`Delta f = (2pi)/(lambda) . (lambda)/(8) = (pi)/(4)`
` I ' - I + I + 2I cos .(pi)/(4) = (2 + sqrt(2))I`
` I = (a+a)^(2) = 4I`
`(I)/(I) = (2 + I. 4I)/(4) = (3.14)/(4) = 0.8525`
` ~ = 0.853`