Electric and magnetic SI units

Analogies can be found between the electrical circuit and the magnetic circuit. According to the ohmic resistance, a magnetic resistance is therefore defined in a magnetic circuit. In an electrical circuit the voltage is the reason for the electric current. The magnetic field of an electromagnet is induced by the magnetomotive force of an operating coil. Thus, the magnetomotive force corresponds to the magnetic voltage.

Symbol	Name of Quantity	Derived Units	Unit	Equation
U	Voltage	Volt	V
Q	Magnetomotive force	Ampere	A	Q = I * N
I	Electric current	Ampere	A
F	Magnetic flux	Weber	Wb (Vs)
J	Electric current density	Ampere/Square meter	A/m2
B	Magnetic field density	Tesla	T	B = F / A
s	Electrical conductivity	Siemens / Meter	S/m
µ	Permeability	Henry/Meter	H/m	µ = µ0 * µr
R	Electrical resistance	Ohm	1Ú2
Rm	Electrical resistance	Ampere/Weber	A/Wb	Rm = l/(µ*A)
G	electrical conductance	Siemens	S	G = 1 / R
L	Magnetic permeance	Weber/Ampere	Wb/A	L = 1 / Rm
Ohm’s Law	U = I * R		Q = F * Rm
L	Inductance	Henry	H
C	Capacitance	Farad	F
P	Real power	Watt	W
S	Complex power	Voltampere	VA
Q	Reactive power	Voltampere / Reactive	var
E	Electric field	Volt/Meter	V/m
Q	Electric Charge	Coulomb	C
D	Electric displacement field	Coulomb / Squaremeter	C/m2
H	Magnetic field	Ampere / Meter	A/m

« Back