Electro-magnetic pulser efficiency

[e2m2a]

Suppose there is an object with a permanent magnet attached to it that can slide on a linear track. The object is initially at rest and the permanent magnet alligns with the axis of an electro-magnet. If the electro-magnet is pulsed on momentarily with a current so that the object acquires a kinetic energy equal to 1 joule, typically how much electrical energy would be needed for the object to acquire this kinetic energy? I assume it would take more that 1 joule of electrical energy to impart 1 joule of kinetic energy to the object. But how much? What would be the theoretical maximum efficieny of the electro-magnetic pulser?

 

[anorlunda]

Energy will be conserved. So where else would the energy go? Into resistance heating is the primary answer. So your question can't be answered without knowing the resistances.

In other words, your question has nothing to do with magnetics, but rather with circuit implementation.