An infinitely long uniform line charge distribution of charge per unit length λ lies parallel to the y-axis in the y-z plane at $\mathrm{z}=\frac{\sqrt{3}}{2}\mathrm{a}$ (see figure). If the magnitude of the flux of the electric field through the rectangular surface ABCD lying in the x-y plane with its centre at the origin is $\frac{\mathrm{\lambda L}}{{\mathrm{n\epsilon }}_0}$ (ε₀ = permittivity of free space), then the value of n is