The resistance that opposes magnetic lines of flux is known as?

The term that refers to the resistance opposing magnetic lines of flux is reluctance. Reluctance is analogous to resistance in electric circuits but specifically applies to magnetic circuits. Just as resistance limits the flow of electric current, reluctance limits the flow of magnetic flux. It is an important concept in understanding magnetic circuits and electromagnetism, particularly when analyzing materials and configurations that influence the behavior of magnetic fields.

Impedance, on the other hand, pertains primarily to the opposition faced by alternating current (AC) in electrical circuits and encompasses both resistance and reactance. Reactance specifically relates to the opposition in AC circuits due to capacitors and inductors, without directly concerning magnetic flux. Conductance measures how easily electric current can flow through a conductor but does not relate to magnetic properties. Thus, reluctance stands out as the correct choice for describing the opposition to magnetic lines of flux.