In a circuit with resistance, inductance, and capacitance, the obstruction to alternating current is called impedance. Impedance is commonly represented by Z, is a complex number, the real part is called the resistance, the imaginary part is called the reactance, where the capacitor in the circuit to the AC obstruction is called the capacitive reactance, the inductance in the circuit to the AC obstruction is called the inductive reactance, capacitance and inductance in the circuit to the AC caused by the obstruction is called the reactance. The unit of impedance is ohms.
In a circuit, Z means impedance
The electronic component symbol Z generally stands for: voltage regulator. Such as DZ: voltage regulator diode; VZ: Stable voltage, etc. If it is used to represent the obstruction of the circuit element to the current, it is to represent the impedance.
Impedance is a complement to resistance, and if a circuit has only resistive elements, then the impedance is the resistance. If there is an inductance capacitor is not the same, but also add the corresponding impedance of the capacitive inductance.