Admittance
In electrical engineering, the admittance (Y) is the inverse or reciprocal of the impedance (Z). The SI unit of Admittance is the siemens.
- <math>Y = Z^{-1} = 1/Z \,<math>
where
Y is the admittance, measured in siemens
Z is the impedance, measured in ohms
Just as impedance is complex resistance, and the conductance G is the inverse G = 1/R of resistance R, admittance is also complex conductance.
Likewise, admittance is made up of a real part (the conductance), and an imaginary part (the susceptance B), shown by the equation
- <math>Y = G + j B \,<math>
The magnitude of admittance is given by:
- <math>\left | Y \right | = \sqrt {G^2 + B^2} \,\!<math>
where
G is the conductance, measured in siemens
B is the susceptance, measured in siemens
SI electricity units
| SI electromagnetism units | |||
|---|---|---|---|
| Name | Symbol | Dimensions | Quantity |
| ampere (SI base unit) | A | A | Current |
| coulomb | C | A·s | Electric charge, Quantity of electricity |
| volt | V | J/C = kg·m2·s−3·A−1 | Potential difference |
| ohm | Ω | V/A = kg·m2·s−3·A−2 | Resistance, Impedance, Reactance |
| ohm metre | Ω·m | kg·m3·s−3·A−2 | Resistivity |
| farad | F | C/V = kg−1·m−2·A2·s4 | Capacitance |
| farad per metre | F/m | kg−1·m−3·A2·s4 | Permittivity |
| reciprocal farad | F−1 | kg1·m2·A−2·s−4 | Elastance |
| siemens | S | Ω−1 = kg−1·m−2·s3·A2 | Conductance, Admittance, Susceptance |
| siemens per metre | S/m | kg−1·m−3·s3·A2 | Conductivity |
| weber | Wb | V·s = kg·m2·s−2·A−1 | Magnetic flux |
| tesla | T | Wb/m2 = kg·s−2·A−1 | Magnetic flux density |
| ampere per metre | A/m | m−1·A | magnetic induction |
| ampere-turns per weber | A/Wb | kg−1·m−2·s2·A2 | Reluctance |
| henry | H | V·s/A = kg·m2·s−2·A−2 | Inductance |
| henry per metre | H/m | kg·m·s−2·A−2 | Permeability |
| (dimensionless) | - | - | Magnetic susceptibility |
External links
Categories: Physical quantity | Electricity