A single current carrying loop of wire carrying current I flowing in anticlockwise direction seen from +ve z-direction and lying in xy plane is shown in figure. The plot of $\hat{\mathrm{j}}$-component of magnetic field (${\mathrm{B}}_{\mathrm{y}}$) at a distance $‘ \mathrm{a} ’$ (less than radius of the coil) and on$\mathrm{yz}-\mathrm{plane}$ vs $\mathrm{z}-\mathrm{coordinate}$ looks like