Question

An interference is observed due to two coherent sources S₁ placed at origin and S₂ placed at (0, 3λ, 0). Here λ is the wavelength of the wavelength of the sources. A detector D is moved along the positive x-axis. Find x-coordinates on the x-axis (excluding x = 0 and x = ∞) where maximum intensity is observed.

Answer 1

At x = 0, path difference is 3. Hence, third order maxima will be obtained, At x = ∞, path difference is zero. Hence, zero order maxima is obtained. In between first and second order maximas will be obtained.

First order maxima :