The figure shows a Young's double slit experimental setup. It is observed that when a thin trans....

The figure shows a Young's double slit experimental setup. It is observed that when a thin transparent sheet of thickness and refractive index is put in front of one of the slits, the central maximum gets shifted by a distance equal to fringe widths. If the wavelength of light used is will be (2019)
(a)
(b)
(c)