Electromotive force
= Electromotive force
{title2=$\mathcal E$}
{wiki}
<Electromotive force> is the driving <work> per unit <electric charge> around an <electrical circuit>, measured in <volts>, despite its name containing "force". For a stationary loop its electromagnetic contribution is $\mathcal E=\oint_C\mathbf E\cdot d\mathbf l$; for a moving <electrical conductor>, include the <motional electromotive force>. A nonzero closed-loop <line integral> of the <electric field> cannot be represented by a single-valued <electric potential> alone. An <electromotive force> specifies the drive; the resulting <electric current> also depends on the <electrical resistance> and <self-inductance>. https://www.feynmanlectures.caltech.edu/II_17.html#Ch17-S1[Feynman lectures, II.17.1: emf as a circuit integral]{ref}.