Magnetomotive force (mmf) Magnetomotive force is the flux producing ability of an electric current in a magnetic circuit. [It is something similar to electromotive force in an electric circuit]. [Unit of magnetomotive force is ampere (A)] Note: Although some books use the term ampere-turns, it is strictly not correct as turns is not a dimension] mmf I = Σ I Consider a coil having N turns as sho...