In general , the relationship between the time-varying voltage v -LRB- t -RRB- across an inductor with inductance L and the time-varying current i -LRB- t -RRB- passing through it is described by the differential equation : When there is a sinusoidal alternating current -LRB- ORGANIZATION@1 -RRB- through an inductor , a sinusoidal voltage is induced .

In general , the relationship between the time-varying voltage v -LRB- t -RRB- across an inductor with inductance L and the time-varying current i -LRB- t -RRB- passing through it is described by the differential equation : How inductors are used Inductors are used often in analog circuits .
