Magnetomotive Force - Equations

Equations

The magnetomotive force in an inductor or electromagnet consisting of a coil of wire is given by:

where N is the number of turns of wire in the coil and I is the current in the wire.

The equation for the magnetic flux in a magnetic circuit, sometimes known as Hopkinson's law, is:

where Φ is the magnetic flux and is the reluctance of the magnetic 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.