Inductors
Since the voltage created depends in this case on the changing magnetic field,
DV = D[ (N B A cos(qBA) ] / Dt .
and the field depends on the changing current,
B = (mo/4p) I DL sin(qIr) / r2
we have: Vinductor = -L DI / Dt
where the L (called the inductance) depends on the shape and material
(just like capacitance and resistance).