6. An interference is observed due to two coherent sources 'A' and 'B' having phase constant zero separated by a distance 4 λ along the y-axis where λ is the wavelength of the source . A detector D is moved on the positive x-axis. The number of points on the x-axis excluding the points x=0 & x= ∞ at which maximum will be observed is, (A) three (B) four (C) two (D) infinite Share with your friends Share 24 Decoder_2 answered this Dear Student, Let BD =x n For maximum intensity, AD-BD=nλ or AD=nλ+xnFrom figure,AD2=(AB)2+(BD)2(nλ+xn)2=(4λ)2+x2nsolving for xn we havexn=16λ2-n2λ22nλwhen n=1x1=16λ2-λ22λ=7.5λsimilarly when n=2x2=3λand when n=3x3=76λso the number of points at which maximum will be observed is 3. Regards 8 View Full Answer