1.4 Inductors

An inductor is usually a coil of wire. A steady current flowing through an inductor produces a magnetic field in the coil. Changing the magnetic field and thus the current requires the application of a voltage across the coil.

Mathematically,

v = L di/dt
where L is the inductance in Henry's.

For fluctuating voltages and currents this expression maybe simplified by performing the same substitutions as we did for the capacitor. The result is,

V = I jwL
The impedance of an inductor is thus jwL.

An inductor does not dissipate any power. Combinations of inductors in series or parallel add in the same way as resistors.