M.M.F. stands for magnetomotive force. M.M.F. is the force behind the flow of magnetic flux. MMF is defined as the force behind the flow of magnetic flux or production of magnetic flux is called as magnetomotive force (M.M.F.).
M.M.F = NI
Where, N = number of turns
I = current flowing through the coil.
MMF is given by product of number of turns of coil and current flowing through the coil.
The unit of current is ampere and unit for number of turns is turns. So the unit for M.M.F. is ampere turns.