Fig, here shows P and Q as two equally intense coherent sources emitting radiations of wavelength 20m. The separation PQ si 5m, and phase of P is ahead of the phase Q by `90^(@)`. A, B and C are three distant points ofobservation equidistant from the mid - point of PQ. The intensity of radiations of A, B, C will beasr the ratio

Options

A. `0:1:4`
B. `4:1:0`
C. `0:1:2`
D. `2:1:0`

Answer

D

Explanation

`Delta phi = theta +- (2pi)/(lambda) (Delta x) , I = I_(0) cos^(2) (theta)/(2)`