Susceptance

In electrical engineering, the susceptance (B) is the imaginary part of the admittance. In SI units, the susceptance is measured in siemens. In June of 1887, Oliver Heaviside used the term "permittance" which later became susceptance.

Mathematics

$Y=G+jB\,$

where

Y is the admittance, measured in siemens

G is the conductance, measured in siemens

$j={\sqrt {-1}}\,$

B is the susceptance, measured in siemens.

The admittance (Y) is the inverse of the impedance (Z)

$Y=1/Z\,$

where

$Z=R+jX\,$

Z is the impedance, measured in ohms

R is resistance, measured in ohms

X is the reactance, measured in ohms.

Note: The susceptance is NOT the inverse of the reactance.

The magnitude of admittance is given by:

$\left|Y\right|={\sqrt {G^{2}+B^{2}}}\,$

SI electricity units

SI electromagnetism units

Symbol	Name of quantity	Unit name	Symbol	Base units
E	energy	joule	J = C⋅V = W⋅s	kg⋅m2⋅s−2
Q	electric charge	coulomb	C	A⋅s
I	electric current	ampere	A = C/s = W/V	A
J	electric current density	ampere per square metre	A/m2	A⋅m−2
U, ΔV; Δϕ; E, ξ	potential difference; voltage; electromotive force	volt	V = J/C	kg⋅m2⋅s−3⋅A−1
R; Z; X	electric resistance; impedance; reactance	ohm	Ω = V/A	kg⋅m2⋅s−3⋅A−2
ρ	resistivity	ohm metre	Ω⋅m	kg⋅m3⋅s−3⋅A−2
P	electric power	watt	W = V⋅A	kg⋅m2⋅s−3
C	capacitance	farad	F = C/V	kg−1⋅m−2⋅A2⋅s4
ΦE	electric flux	volt metre	V⋅m	kg⋅m3⋅s−3⋅A−1
E	electric field strength	volt per metre	V/m = N/C	kg⋅m⋅A−1⋅s−3
D	electric displacement field	coulomb per square metre	C/m2	A⋅s⋅m−2
ε	permittivity	farad per metre	F/m	kg−1⋅m−3⋅A2⋅s4
χe	electric susceptibility	(dimensionless)	1	1
p	electric dipole moment	coulomb metre	C⋅m	A⋅s⋅m
G; Y; B	conductance; admittance; susceptance	siemens	S = Ω−1	kg−1⋅m−2⋅s3⋅A2
κ, γ, σ	conductivity	siemens per metre	S/m	kg−1⋅m−3⋅s3⋅A2
B	magnetic flux density, magnetic induction	tesla	T = Wb/m2 = N⋅A−1⋅m−1	kg⋅s−2⋅A−1
Φ, ΦM, ΦB	magnetic flux	weber	Wb = V⋅s	kg⋅m2⋅s−2⋅A−1
H	magnetic field strength	ampere per metre	A/m	A⋅m−1
F	magnetomotive force	ampere	A = Wb/H	A
R	magnetic reluctance	inverse henry	H−1 = A/Wb	kg−1⋅m−2⋅s2⋅A2
P	magnetic permeance	henry	H = Wb/A	kg⋅m2⋅s-2⋅A-2
L, M	inductance	henry	H = Wb/A = V⋅s/A	kg⋅m2⋅s−2⋅A−2
μ	permeability	henry per metre	H/m	kg⋅m⋅s−2⋅A−2
χ	magnetic susceptibility	(dimensionless)	1	1
m	magnetic dipole moment	ampere square meter	A⋅m2 = J⋅T−1	A⋅m2
σ	mass magnetization	ampere square meter per kilogram	A⋅m2/kg	A⋅m2⋅kg−1

External links

• Conductance, Susceptance, and Admittance