Magnetic Circuit MCQ Questions & Answers | Electrical Engineering

Hysteresis loss occurs in a magnetic material due to the lagging of flux density (B) behind the magnetizing force (H) when the material undergoes cyclic magnetization. This delay in response leads to energy dissipation in the form of heat, which is represented by the area enclosed by the hysteresis loop.

Why Not the Other Options?

Option A: Rapid reversals of its magnetization – This contributes to hysteresis loss but is not the root cause. The loss happens due to the delay in realigning the magnetic domains, not just the rapid changes themselves.

Option C: Molecular friction – This is a misleading term. While there is internal resistance in domain movement, hysteresis loss is primarily due to flux lag rather than physical friction at the molecular level.

Option D: Its high retentivity – Retentivity refers to a material’s ability to retain magnetization after the external field is removed. A material with high retentivity does not necessarily have high hysteresis loss. Retentivity influences the shape of the hysteresis loop but is not the direct cause of hysteresis loss.

Thus, Option B is the correct answer.