Magnetics

The magnetic moments associated with two closely wound circular coils \(\mathrm{A}\) and \(\mathrm{B}\) of radius \(\mathrm{r}_{\mathrm{A}}=10\) \(\mathrm{cm}\) and \(\mathrm{r}_{\mathrm{B}}=20 \mathrm{~cm}\) respectively are equal if : (Where \(\mathrm{N}_{\mathrm{A}}, \mathrm{I}_{\mathrm{A}}\) and \(\mathrm{N}_{\mathrm{B}}, \mathrm{I}_{\mathrm{B}}\) are number of turn and current of \(\mathrm{A}\) and \(\mathrm{B}\) respectively)