A Young's double slit interference arrangement with slits S 1 and S 2 is immersed in water (refractive index…

A Young's double slit interference arrangement with slits ${\mathrm{S}}_1$ and ${\mathrm{S}}_2$ is immersed in water (refractive index $=\frac{4}{3}$ ) as shown in the figure. The positions of maxima on the surface of water are given by ${\mathrm{x}}^2={\mathrm{p}}^2{\mathrm{m}}^2{\mathrm{\lambda }}^2-{\mathrm{d}}^2$ , where $\mathrm{\lambda }$ is the wavelength of light in air (refractive index = 1), $2\mathrm{d}$ is the separation between the slits and m is an integer. The value of p is