Magnetic materials: the ability of a material to retain magnetization after the magnetizing force is removed is called “retentivity.” Confirm or refute this definition.

Introduction / Context:
Magnetic materials are characterized by properties such as permeability, saturation, remanence, retentivity, and coercivity. Understanding these terms is essential for selecting core materials and designing magnetic devices.

Given Data / Assumptions:

• Materials are ferromagnetic or ferrimagnetic and exhibit hysteresis.
• We consider quasi-static magnetization cycles to define properties.
• Terminology follows standard SI/engineering usage.

Concept / Approach:
Retentivity refers to how well a material retains magnetic flux density after the external magnetizing field is removed. The measured residual magnetization is called remanence (or remanent flux density), and a material with high retentivity strongly holds that remanence. Coercivity is the reverse field needed to bring flux back to zero. The statement maps correctly to these definitions: the “ability to maintain magnetization” aligns with retentivity.

Step-by-Step Solution:

Verification / Alternative check:
Hysteresis loops show vertical intercept (remanence) and loop shape; materials with wide loops exhibit high retentivity and coercivity, matching this definition.

Why Other Options Are Wrong:
Incorrect: conflicts with standard magnetic terminology.

Limiting to permanent magnets or room temperature is unnecessary; retentivity is a property measurable across conditions.

Common Pitfalls:
Confusing retentivity with coercivity; equating “remanence” (a value) with “retentivity” (a material tendency/capability).

Final Answer:
Correct