EMEC - Greg

Definitions

Electromagnetism Units

Symbol	Units	Name	Definition
		Flux	The rate of transfer of energy (or another physical quantity) per unit area <ref> http://en.wiktionary.org/wiki/flux </ref>
$\overrightarrow{E}$	$\frac{V}{M}$	Electric Field Intensity	The space surrounding an electric charge. It will exert a force on other electrically charged objects.
$\overrightarrow{D}$	$\frac{C}{M^2}$	Electric Flux Density
$\overrightarrow{H}$	$\frac{A}{M}$	Magnetic Field Intensity
$\overrightarrow{B}$	$T=\frac{W}{M^2}$	Magnetic Flux Density

Analogies between Electric & Magnetic Circuits

Electric	Magnetic	Notes
$V=\int \overrightarrow{E}\overrightarrow{dl}$	$\overrightarrow{F}=\int \overrightarrow{H}\overrightarrow{dl}$
$\sum _n{V}_n=0=\oint \overrightarrow{E}\overrightarrow{dl}$	$\oint \overrightarrow{H}\overrightarrow{dl}=Ni=\sum _{n}Hl+Ni=0$	Kirchoff's voltage law, Ampere's law
$\sum _n{I}_n=0={\oint }_S\overrightarrow{J}\overrightarrow{dS}$	$\oint \overrightarrow{B}\overrightarrow{dS}=0$	Kirchoff's current law, The B-field has to go around in a loop
$\oint \overrightarrow{J}\overrightarrow{dS}=I$	$\int \overrightarrow{B}\overrightarrow{dS}=\mathrm{\Phi }$	Magnetic flux, Phi
$R=\frac{V}{I}$	$\mathfrak{\Re }=\frac{F}{\mathrm{\Phi }}=\frac{Ni}{\mathrm{\Phi }}$	Reluctance
$I=\frac{V}{R}=GV$ or $\overrightarrow{J}=\sigma \overrightarrow{E}$	$\overrightarrow{B}=\mu H$	Assumes linearity - exceptions: Hysterisis loop, etc