ABSTRACT
Admittance Y siemen S
Angular frequency ω radians per second rad/s
Area A square metres m2
Attenuation coefficient (or constant) α neper Np
Capacitance C farad F
Charge Q coulomb C
Charge density σ coulomb per square metre C/m2
Conductance G siemen S
Current I ampere A
Current density J ampere per square metre A/m2
Efficiency η per unit or per cent p.u. or %
Electric field strength E volt per metre V/m
Electric flux coulomb C
Electric flux density D coulomb per square metre C/m2
Electromotive force E volt V
Energy W joule J
Field strength, electric E volt per metre V/m
Field strength, magnetic H ampere per metre A/m
Flux, electric coulomb C
Flux, magnetic weber Wb
Flux density, electric coulomb per square metre C/m2
Flux density, magnetic tesla T
Force newton N
Frequency hertz Hz
Frequency, angular radians per second rad/s
(Continued)
QUANTITY QUANTITY UNIT UNIT SYMBOL SYMBOL
Frequency, rotational n revolutions per second rev/s
Impedance Z ohm
Inductance, mutual M henry H
Inductance, self L henry H
Length l metre m
Loss angle δ radian or degrees rad or ◦
Magnetic field strength H ampere per metre A/m
Magnetic flux weber Wb
Magnetic flux density B tesla T
Magnetic flux linkage weber Wb
Magnetizing force H ampere per metre A/m
Magnetomotive force Fm ampere A
Mutual inductance M henry H
Number of phases m – –
Number of pole-pairs p – –
Number of turns (of a winding) N – –
Period, Periodic time T second s
Permeability, absolute μ henry per metre H/m
Permeability of free space μ0 henry per metre H/m
Permeability, relative μr – –
Permeance weber per ampere or per henry Wb/A or /H
Permittivity, absolute ε farad per metre F/m
Permittivity of free farad per metre F/m
Permittivity, relative – –
Phase-change radian rad
Potential, Potential volt V
Power, active watt W
Power, apparent volt ampere VA
Power, reactive volt ampere reactive var
Propagation coefficient – –
(Continued)
QUANTITY QUANTITY UNIT UNIT SYMBOL SYMBOL
Quality factor, magnification Q – –
Quantity of electricity Q coulomb C
Reactance X ohm
Reflection coefficient ρ – –
Relative permeability μr – –
Relative permittivity εr – –
Reluctance S or Rm ampere per weber or per henry A/Wb or /H
Resistance R ohm
Resistance, temperature coefficient of α per degree Celsius or per kelvin / ◦C or /K
Resistivity ρ ohm metre m
Slip s per unit or per cent p.u. or %
Standing-wave ratio s – –
Susceptance B siemen S
Temperature coefficient of resistance α per degree Celsius or per kelvin / ◦C or /K
Temperature, thermodynamic T kelvin K
Time t second s
Torque T newton metre Nm
Velocity v metre per second m/s
Velocity, angular ω radian per second rad/s
Volume V cubic metres m3
Wavelength λ metre m
(Note that m/s may also be written as ms−1, C/m2 as Cm−2, /K as K−1, and so on.)
