Current is voltage over impedance

Alternating current flowing through an electric component is proportional to voltage applied to it and inversely proportional to its impedance. This is the complex generalization of the Ohm’s law.

Notes:

  1. This is a phenomenological equation.

Conditions:

  1. The material must be ohmic, i.e. current must be proportional to voltage.

  2. The AC circuit must be time-invariant.

Links:

  1. Wikipedia — Ohm’s law.

  2. Univeristy of Maryland — Complex impedance method for AC circuits.

current

Phasor current through the component.

Symbol:

I

Latex:

\(I\)

Dimension:

current

voltage

Phasor voltage across the component.

Symbol:

V

Latex:

\(V\)

Dimension:

voltage

impedance

electrical_impedance of the component.

Symbol:

Z

Latex:

\(Z\)

Dimension:

impedance

law

I = V / Z

Latex:
\[I = \frac{V}{Z}\]