question_answer

A thin glass plate of thickness \[\frac{2500}{3}\lambda (\lambda \] 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 from the slits, the ratio of the intensities before and after the introduction of the glass plate is:                                            [JEE ONLINE 25-04-2013]

A)             2 : 1

B) 1 : 4

C)             4 : 1

D) 4 : 3