+++ title = "Electromagnetism" author = ["Dehaeze Thomas"] draft = false +++ Tags : ## Maxwell equations for magnetics {#maxwell-equations-for-magnetics} ### Gauss law {#gauss-law} "Magnetic fieldlines are closed loop." \begin{equation} \oiint\_S (\bm{B} \cdot \hat{\bm{n}}) dS = 0 \end{equation} ### Faraday's law {#faraday-s-law} A changing magnetic field causes an electric field over a wire \begin{equation} \oint\_L \bm{E} \cdot d\bm{l} = -\frac{d}{dt} \iint\_S(\bm{B} \cdot \bm{n}) dS \end{equation} The line-integral of the electrical field over a closed loop L equals the change of the field through the open surface S bounded by the loop L. This is a voltage source (EMF), where the current is driven in the direction of the electric field. ### Ampère's law {#ampère-s-law} "Current through a wire gives a magnetic field". \begin{equation} \oint\_L \bm{B} \cdot dl = \mu\_0 I \end{equation} The line integral of the magnetic field over a closed loop L is proportional to the current through the surface S enclosed by the loop L. ## Bibliography {#bibliography}