An apparatus includes one or more magnetic cores collectively having an inner leg located between two outer legs. The legs are coupled to one or more connecting portions. The apparatus also includes one or more conductive coils wound around the inner leg. The one or more magnetic cores and the one or more conductive coils are configured to generate substantially balanced magnetic fluxes when the conductive coil is energized. Also, the one or more magnetic cores and the one or more conductive coils are configured so that heat created by currents induced in the roll by the magnetic fluxes produces a steady state thermal profile on a surface of the roll. The steady state thermal profile has one peak that falls within a control zone associated with the roll. The one or more magnetic cores could include a single magnetic core or multiple magnetic cores.