Conduction current
= Conduction current
{title2=$\mathbf J_c=\sigma\mathbf E$}
A <conduction current> is transport of <electric charge> by mobile carriers through matter. For a local isotropic ohmic medium, its <current density> is $\mathbf J_c=\sigma\mathbf E$, with <electrical conductivity> $\sigma$. It differs from <displacement current> $\partial\mathbf D/\partial t$, which can be nonzero in a capacitor's insulating gap without carriers crossing the gap.