A double slit with distance between slits 'd' is kept parallel to a large screen. Screen lies at a distance D from the double slit. One of the slits is covered with a transparent and very thin slab as shown in figure. Refractive index of slab varies with time according to relation $\text{μ=}\frac{\text{3}}{\text{2}}\left({\text{1+cos}}^{\text{2}}\text{2πt}\right)$. The complete set up is situated in air $({\mu }_{air}\approx 1)$. At the double slit is illuminated with a parallel beam of monochromatic light of wavelength $\lambda$ as shown below and continues to fall for a very long time. Thickness of slab is equal to wavelength of light incident on the slits. Intensity of falling beam is ${\text{I}}_{\text{0}}$. Assume that d<<D.