[[Electrodynamics MOC]]
# Electromagnetostatics MOC

**Electromagnetostatics** is a special case of [[Electrodynamics MOC|electrodynamics]] where the [[electric field]] and [[Magnetic field]] are time-independent, i.e.
$$
\begin{align*}
\frac{ \partial \vab B }{ \partial t } &=\vab 0 & \frac{ \partial \vab E }{ \partial t } &= \vab 0
\end{align*}
$$
Electromagnetostatic phenomena are essentially the “direct sum” of [[Electrostatics MOC|electrostatic]] and [[Magnetostatics MOC|magnetostatic]] phenomena,
in that [[Maxwell's equations]] reduce to
$$
\begin{align*}
\vab{\nabla} \cdot \vab E &= \frac{\rho_{q}}{\epsilon_{0}}
&
\vab{\nabla}\cdot\vab B &= 0
&
\vab{\nabla}\times\vab E &= \vab 0 
&
\vab{\nabla}\times\vab B &= \mu_{0}\vab J
\end{align*} 
$$
The [[Poynting vector]] and thus [[Electromagnetic momentum density|momentum density]] are non-vanishing but static.



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