Magnetomotive force
In physics, the
magnetomotive force is a quantity appearing in the equation for the magnetic flux in a magnetic circuit, sometimes known as Hopkinson's law: where
Φ is the magnetic flux and
ℛ is the reluctance of the circuit. It can be seen that the magnetomotive force plays a role in this equation analogous to the voltage
V in Ohm's law:
V =
IR. Magnetomotive force is analogous to electromotive force, emf since it is the cause of magnetic flux in a magnetic circuit; i.e., ▪
ℱ =
NI where
N is the number of turns in the coil and
I is the electric current through the circuit ▪
ℱ =
Φℛ where
Φ is the magnetic flux and
ℛ is the reluctance ▪
ℱ =
Hl where
H is the magnetizing force and
l is the mean length of a solenoid or the circumference of a toroid...