Self-inductance
= Self-inductance
{title2=$\Lambda=LI,\quad\mathcal E_{\rm ind}=-L\dot I$}
For a circuit whose flux linkage $\Lambda$ is proportional to its current, the self-inductance is the coefficient $L$ in $\Lambda=LI$. <Faraday's law> gives the induced <electromotive force> $-L\dot I$ when $L$ is constant. In series with a resistance $R$ and a constant applied electromotive force, the current obeys $L\dot I+RI=\mathcal E_0$, with <time constant> $L/R$.