Moving-conductor Ohm law
= Moving-conductor Ohm law
{title2=$\mathbf E+\mathbf u\times\mathbf B=\mathbf J/\sigma$}
In the nonrelativistic scalar-conductivity approximation, neglecting Hall and other nonideal electromotive effects, $\mathbf J=\sigma(\mathbf E+\mathbf u\times\mathbf B)$. The ideal finite-current limit gives $\mathbf E=-\mathbf u\times\mathbf B$ and hence the <ideal magnetohydrodynamic induction equation>.