look at this web page, it is simple. http://hyperphysics.phy-astr.gsu.edu/Hbase/electric/imped.html
the paralel
The impedance of electric circuit refers to the measure of the opposition that a circuit presents to a current when a voltage is applied.
You need to divide the supply voltage by the impedance of the load. The impedance of the load is the vectorial sum of its resistance and reactance, where reactance is proportional to frequency.
To calculate the admittance if you are given the impedance, you take the inverse of the impedance ( that is 1/z).
impedance
A parallel circuit
In an electrical circuit, impedance and phase angle are related because impedance affects the phase angle of the current in the circuit. The phase angle represents the time delay between the voltage and current waveforms in the circuit. A change in impedance can cause a shift in the phase angle, impacting the overall behavior of the circuit.
A parallel resonant circuit has low impedance, when non resonant; however the impedance rises sharply, as the circuit comes to resonance.
In an electrical circuit, the phase angle represents the time delay between the voltage and current waveforms. The impedance of a circuit is the total opposition to the flow of current. The relationship between phase angle and impedance is that the phase angle is determined by the ratio of the reactance to the resistance in the circuit, which affects the overall impedance.
Impedance
AnswerThe unit of measurement for impedance is the ohm.
No, impedance inversion cannot be achieved with a short circuit stub. A short circuit stub will have a low impedance at the point where it is connected, which will not invert the impedance at that point. Impedance inversion can be achieved using techniques such as a quarter-wave transformer or a transmission line with specific impedance characteristics.