The microscopic form of Ampere's law with the Maxwell addition in Gaussian units states,

\begin{equation} \nabla \times \vec{B} = \frac{1}{c} \left ( 4 \pi \vec{J} + \frac{\partial \vec{E}}{\partial t} \right ), \end{equation}

Where $\vec{B}$ is the magnetic field density (in Gauss); $\vec{J}$ is the free current density (in statC cm$^{-2}$ s$^{-1}$); and $\vec{E}$ is the electric field (in statV cm$^{-1}$).

How is it that the free density term, $\vec{J}$ and the time derivative of the electric field, $\frac{\partial \vec{E}}{\partial t}$, have the same Gaussian units? I see how it this works out with CGS, but not if I try and stay in Gaussian only units.


A statvolt is a statcoulomb per centimeter, because the electrostatic potential of a point charge in Gaussian units is $\varphi=q/r$.


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