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 \( \, \hat{\jmath} \, \) component of magnetic field \( (B_y) \) at a distance \( a\) (less than radius of the coil) and on \( yz \) plane vs \( z \) coordinate looks like:
