IMPORTANT ELECTRICAL ENGINEERING UNITS

Unit
Symbol
General Quantities
m/s2  (metre/second/second)
a
Acceleration, linear
m2  (square metre)
A
Area
J (joule)
W
Energy or work
N (newton)
F
Force
m (meter)
l
Length
kg (kilogram)
m
Mass
W (watt)
P
Power
Pa (pascal)
p
Pressure
K or °C (Kelvin or degree Celsius)
θ
Temperature value
s (second)
t
Time
Nm (newton metre)
T
Torque
rad/s (radian/second)
ω
Velocity, angular
m/s (metre/second)
v or u
Velocity, linear
m3  (cubic metre)
V
Volume
m meter
λ
Wavelength
Unit
Symbol
Electrical Quantities
Ω(ohm)
Y
Admittance
C (coulomb)
Q
Charge (quantity)
S (siemen)
G
Conductance
A (ampere)
I
Current
A/m2  (ampere/square
metre)
J
Current density
V (volts)
E
Electromotive force (emf)
Hz (hertz)
f
Frequency
Ω (ohm)
Z
Impedance
s (second)
T
Period
V (volt)
V
Potential difference (p.d.)
W (watt)
P
Power, active
VA (volt ampere)
S
Power, apparent
VAr (volt ampere reactive)
Q
Power, reactive
Ω (ohm)
X
Reactance
Ω (ohm)
R
Resistance
Ωm (ohm metre)
ρ
Resistivity
s (second)
t
Time constant
Unit
Symbol
Electrostatic Quantities
F (farad)
C
Capacitance
V/m (volt/metre)
E
Field strength
C (coulomb)
Ψ
Flux
C/m2  (coulomb/square
metre)
D
Flux density
F/m (farad/metre)
ε
Permittivity, absolute
Unit
Symbol
General
Quantities
 no units
εr  
Permittivity,
relative
F/m
(farad/metre)
   ε0  
Field strength
Unit
Symbol
Electromagnetic Quantities
At/m (ampere turn/metre)
H
Field strength
Wb (weber)
Φ
Flux
T (tesla)
B
Flux density
H (henry)
M
Inductance, mutual
H (henry)
L
Inductance, self
At (ampere-turn)
F
Magnetomotive force (mmf)
H/m (henry/metre)
μ
Permeability, absolute
no units
μr
Permeability, relative
H/m (henry/metre)
μ0
Permeability, of free space
At/Wb (ampere turn/weber) Siemens
S
Reluctance