What term describes the heating of an inductive iron core by circulating current that is reduced by the magnetic field around the coil?

The correct term for the phenomenon described is "eddy current loss." This term refers to the losses that occur when electric currents, known as eddy currents, are induced in conductors due to a changing magnetic field. In the context of an inductive iron core, these currents are generated when alternating current flows through the winding, leading to a creation of magnetic fields that can induce current loops (eddy currents) within the core material itself.

These eddy currents flow opposite to the direction of the changes in the magnetic field, resulting in energy being lost in the form of heat. The larger the area of the conductive material and the higher the frequency of the alternating current, the greater the eddy current loss will be. Therefore, this process is crucial to consider in the design of transformers and inductors to minimize energy loss and improve efficiency.

Other terms mentioned, like loss of conductance, magnetic loss, and resistive loss, do not specifically capture this interplay of magnetic fields and induced currents, making "eddy current loss" the most accurate descriptor for the scenario presented.