Ferraro's law of isorotation
= Ferraro's law of isorotation
{c}
{title2=$\mathbf B_p\cdot\nabla\Omega=0$}
A stationary axisymmetric <magnetic field> in ideal purely rotational flow requires constant angular velocity along the <magnetic field lines> of its <poloidal magnetic field>. Otherwise <axisymmetric magnetic winding> generates a time-dependent toroidal component.