In the context of electrical circuits and alternating current (AC) fundamentals, admittance is the reciprocal of impedance. It's a complex quantity that encompasses both the conductance and susceptance of a circuit element. Admittance is denoted by the symbol "Y" and is measured in siemens (S).
The components of admittance are similar to those of impedance, but they are reciprocals of impedance components. The components of admittance include:
Conductance (G): Conductance is the real part of admittance and represents the ease with which electric current can flow through a circuit element. It is measured in siemens (S) and is the reciprocal of resistance. Mathematically, conductance is represented as G = 1/R, where R is the resistance.
Susceptance (B): Susceptance is the imaginary part of admittance and indicates the reactive nature of a circuit element. It is measured in siemens (S) and is the reciprocal of reactance. Mathematically, susceptance is represented as B = 1/X, where X is the reactance.
Admittance (Y): Admittance is the overall measure of how easily current can flow through a circuit element, considering both the conductive and reactive aspects. It's a complex quantity consisting of both conductance (G) and susceptance (B). Mathematically, admittance is represented as Y = G + jB, where "j" is the imaginary unit.
The relationship between impedance (Z) and admittance (Y) is given by:
Z = 1 / Y
Where Z is the impedance, and Y is the admittance.
When dealing with AC circuits, the admittance is used to analyze how current and voltage behave in circuits with reactive elements such as capacitors and inductors. Just as impedance helps understand the opposition to the flow of AC current, admittance provides insight into the ease of current flow and the reactive nature of the circuit.