Impedance is the analog to resistance, but in AC! The impedance has a both real and imaginary component, and can be used with Ohm’s Law, in place of R, to calculate quantities. Different components have different reactance, which when combined, result in the impedance of the circuit.
Resistors
Resistors in AC can be modelled as such:
To find the real result, we simply take the cosine of the magnitude (the capital letters).
The reactance of a resistor is simply and is only a real component
Inductors
The reactance of an inductor is Where j is the complex number i.
Capacitors
The reactance of the capacitor is