Answer: Energy dissipated as heat per unit volume of the material in one cycle.
- A The maximum magnetic field reached inside the material
- B Energy dissipated as heat per unit volume of the material in one cycle
- C The retentivity of the material in that one cycle
- D The total magnetic flux passing through the material in one cycle
Correct answer: B. Energy dissipated as heat per unit volume of the material in one cycle
Explanation: The area of the hysteresis loop equals the energy lost as heat per unit volume of the material during one cycle of magnetisation, which is why transformer cores use materials with a small loop area.
Magnetic field of a bar magnet: field lines emerge from the north pole and re-enter at the south pole outside the magnet, forming continuous closed loops. Image: Geek3, CC BY-SA 3.0, via Wikimedia Commons.
Concept context
Bar magnets, Earth's magnetism, and how different materials respond to an external magnetic field - diamagnetic, paramagnetic, and ferromagnetic behaviour.