2.2j.3 Impedance

Impedance

The impedance $Z$ (SI: Ohm/$\Omega$) of any circuit element is defined as the ratio of the phasor voltage across it to the phasor current entering through its plus (+) terminal, such that
$Z=\frac{V}{I}.$
The $v$-$i$ properties of resistors, capacitors and inductors are summarized below:

Proofs

(Resistor Impedance) $Z_R=R$

(Capacitor Impedance) $Z_C=\frac{1}{j\omega C}=-\frac{j}{\omega C}$

(Inductor Impedance) $Z_L=j\omega L$