Which one of the following statements best describes magnetic hysteresis? A. Hysteresis is the amount of magnetic flux that is not confined to the core material of an electromagnet B. Hysteresis is most apparent when a steady amount of current is lowing through the coil of an electromagnet C. Hysteresis is most apparent when the current through the coil of an electromagnet changes frequently D. Hysteresis is most apparent when the core material is saturated E. None of the above

The correct answer is: C. Hysteresis is most apparent when the current through the coil of an electromagnet changes frequently.

Hysteresis is the lagging of the magnetic flux behind the magnetizing force in a magnetic material. It is most apparent when the current through the coil of an electromagnet changes frequently. This is because the magnetic flux in the core material is not able to keep up with the changes in the current, and as a result, there is a lag between the two. This lag can cause problems in some applications, such as in transformers, where it can lead to losses in efficiency.

Option A is incorrect because magnetic flux is the amount of magnetic field lines that pass through a given area. It is not confined to the core material of an electromagnet.

Option B is incorrect because hysteresis is most apparent when the current through the coil of an electromagnet changes frequently. It is not most apparent when a steady amount of current is flowing.

Option D is incorrect because hysteresis is most apparent when the current through the coil of an electromagnet changes frequently. It is not most apparent when the core material is saturated.

Option E is incorrect because hysteresis is a real phenomenon that occurs in magnetic materials. It is not a made-up concept.