Magnetic materials — terminology accuracy: Is the ability of a material to remain magnetized without a continuing magnetizing force called “hysteresis,” or is the correct term “retentivity”?

Introduction / Context:
Precise magnetic terminology matters in transformer design, magnetic storage, and motor control. Two commonly confused terms are hysteresis, which describes a lagging behavior and loop area, and retentivity (remanence), which is the ability to remain magnetized after the external magnetizing field is removed.

Given Data / Assumptions:

• The statement claims that the ability to maintain magnetization is called hysteresis.
• We consider standard definitions from magnetic materials science.
• No unusual materials or extreme conditions are assumed.

Concept / Approach:
On a B–H (magnetic flux density vs. magnetic field strength) curve, hysteresis refers to the loop traced as the material is cycled through magnetization and demagnetization. The area of this loop corresponds to hysteresis loss (energy dissipated per cycle). Retentivity (remanent flux density) is the vertical intercept when H returns to zero—how much magnetization remains without an applied field. Coercivity is the reverse field required to reduce this remanent magnetization to zero. The statement conflates these distinct concepts.

Step-by-Step Solution:

Verification / Alternative check:
Review a standard hysteresis loop: points show B_r (remanent flux density) and H_c (coercive field). The loop area indicates hysteresis loss. This diagram distinguishes retentivity from hysteresis unambiguously.

Why Other Options Are Wrong:
“Correct” confuses terms. Limiting to soft iron, temperature extremes, or tying solely to coercivity does not fix the naming error; coercivity is a different parameter.

Common Pitfalls:
Using “hysteresis” loosely to mean “magnetic memory.” The retained magnetization is retentivity; hysteresis is the path-dependent behavior causing a loop and associated losses.

Final Answer:
Incorrect