Current in a ferromagnetic core with an air gap wrapped by a wire.
In this Demonstration you can see the current in a ferromagnetic core with an air gap wrapped by a wire. The example calculates the reluctance, total flux, and mean path length in a three-dimensional representation. The magnetic circuit is created in a similar form to what would be needed by an electric motor. You can adjust the number of wire wraps and geometry of the system to see the affects on the reluctance and magnetic flux.