**The real part of the admittance of an alternating-current circuit.** The admittance *Y* of an alternating-current circuit is a complex number given by Eq. (1).

The real part *G* is the conductance. The units of conductance, like those of admittance, are called siemens or mhos. Conductance is a positive quantity. The conductance of a resistor *R* is given by Eq. (2).

In general the conductance of a circuit may depend on the capacitors and inductors in the circuit as well as on the resistors.For example, the circuit in the **illustration** has impedance at frequency ω given by Eq. (3) and admittance given by Eq. (4),

so that the conductance, given by Eq. (5),

depends on the inductance *L* as well as the resistance *R*.* See also: ***Admittance**; **Alternating-current circuit theory**; **Electrical impedance**