question_answer

                A thin glass plate of thikness\[\frac{2500}{3}\lambda (\lambda \] is wavelength of light used) and refractive index  \[\mu =1.5\] is inserted between one the slits and the screen Yong?s double slit experiment. At a point on the screen equidistant form the slits, the ratio of the intensities before and after the introduction of the glass plate is:     JEE Main Online Paper ( Held On 25  April 2013 )

A)                 2 : 1                                       

B)                                        1 : 4

C)                                        4 : 1       

D)                                        4 : 3