question_answer

For constructive interference to take place between two monochromatic light waves of wavelength l, the path difference should be                                                    [MNR 1992; UPSEAT 2001]

A)            \[(2n-1)\frac{\lambda }{4}\] 

B)            \[(2n-1)\frac{\lambda }{2}\]

C)            \[n\lambda \]                      

D)            \[(2n+1)\frac{\lambda }{2}\]