Question

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

Answer 1

Answer:

The ratio of intensity to the central fringe is 0.85

Explanation:

Given

The path difference between the waves Δx = λ/8

∴ Δ∅ = (2π/λ)Δx = (2π/λ)(λ/8) = π/4 = 45°

Intensity is given by

$I=I_o\cos^2(\Delta\phi/2)$

or, $I/I_O=\cos^2(\pi/8) = 0.85$

Therefore the ratio of intensity to the central fringe is 0.85

Hope this helps.