Symbol Definition Units Units
    SI CGS
a no. of winding parallel paths -- --
A area    
B flux-density Tesla Gauss
C capacitance farad farad
E emf, voltage Volt Volt
d distance m in
D diameter m in
f frequency Hz Hz
F force Newton lb
h distance m in
H magnetic coercivity At/m Oersted
i current Ampere A
I current Ampere A
J moment of inertia    
J current density    
kl leakage constant -- --
  eddy current constant -- --
  emf constant V/rad/s V/krpm
  hysteris constant -- --
  reluctance coefficient -- --
  torque constant Nm/A oz in
l length m in
L inductance Henry Henry
m number of coils/phase -- --
m number of phases -- --
mmf magneto motive force At Gilbert
n number of turns/coil -- --
p number of poles -- --
P permeance Wb/At M/B
R reluctance At/Wb B/M
R resistance Ohm Ohm
s speed rpm rpm
S steps/rev -- --
t time s s
T torque Nm lb ft
v velocity m/s in/s
V supply voltage Volt Volt
W energy, work Joule Joule
z no. winding conductors -- --
  thermal resistance 1/°C 1/°C
  skin depth m in
  wave length m in
  flux-linkage Weber Maxwell
  permeability Henry/m Henry/in
  damping factor -- --
  mechanical time constant s s
  resistivity Ohm-m Ohm-in
  flux Weber Maxwell
  natural frequency rad/s rad/s