Two coherent sources separated by distance d are radiating in phase having wavelength X. A detector moves in a big circle around the two sources in the plane of the two sources. The angular position n=4 interference maxima is given as

• A. \[{{\sin }^{-1}}\frac{n\lambda }{d}\]
• B. \[{{\cos }^{-1}}\frac{4\lambda }{d}\]
• C. \[{{\tan }^{-1}}\frac{d}{4\lambda }\]
• D. \[{{\cos }^{-1}}\frac{\lambda }{4d}\]