Q 12-05-023NEETJEE MainEasy
The area of the hysteresis loop of a ferromagnetic material is a measure of
Answer: (B) the energy lost as heat per unit volume per cycle
Concept. In one cycle of magnetisation the work done per unit volume on the material is $\oint H\,dB$, which is the area enclosed by the $B$-$H$ loop.
Step 1. Interpret. This energy is not recovered; it appears as heat. So the loop area measures the hysteresis loss per unit volume per cycle. Soft iron has a thin loop, which is why it is used in transformer cores.
Answer. The energy lost as heat per unit volume per cycle (Option B).
Solution by Sreeraj P, M.Sc Physics