Wave Optics

In a YDSE, the light of wavelength \(\lambda=5000\mathop A\limits^o\) is used, which emerges in phase from two slits at \(a\) distance \(d=3 \times 10^{-7} \mathrm{~m}\) apart. A transparent sheet of thickness \(t=1.5 \times 10^{-7} \mathrm{~m}\) and refractive index \(\mu=1.25\) is placed over one of the slits. What is the new angular position of the central maxima of the interference pattern, from the centre of the screen? Find the value of \(y\).