Admittance

In phasor analysis, admittance is a complex number and the reciprocal of impedance. In standard form, admittance is:

$$Y=\frac{1}{Z}=G+jB$$

The real part $G$ is called the conductance and the imaginary part $B$ is called the susceptance, both units of siemens (S).

As a result of its reciprocity, we can write parallel impedances as an equivalent admittance:

$$Y_{eq}=\sum _{k=1}^n{Y}_k$$