What is magneto-motive force ?

Magneto-motive force is considered to be the force derived from a magnetic field.  It is usually considered analogous to the Electromotive force or voltage.  However, the magneto-motive force is not really a force.  It can be better described as the property of certain materials to generate a magnetic field.  

The unit of magneto-motive force is the Ampere-turns in the SI system. In the CGS system, the unit is gilbert.  
One Ampere-turn in the magneto-motive force when one ampere of steady dc current flows through one turn.

The ampere turns can be calculated as the product of the number of turns and the current flowing through it.

F = N x I