Question

Two monochromatic (wavelength = a/5) and coherent sources of electromagnetic waves are placed on the x-axis at the points (2a,0) and (–a,0). A detector moves in a circle of radius R(>>2a) whose centre is at the origin. The number of maximas detected during one circular revolution by the detector are-"

Answer 1

Distance S1 and S2 is 3a.

Given wavelength=a/5, therefore, 3a =15(wavelength) . This corresponds to maxima. ∆x=0 imples maxima. Similarly in three other quadrants we will get 14 maxima. Therefore total = 60