Which magnetic property describes how easily a material becomes magnetized in a magnetic field?

• A. Reluctance
• B. Coercivity
• C. Permeability
• D. Retentivity

Answer: (C)

Permeability is the measure of how easily a material becomes magnetized in a magnetic field. It describes how readily magnetic flux can pass through the material when a magnetic field is applied. In formula form, B = μH, where μ = μ0μr. A higher permeability means a given magnetic field H produces more magnetic flux B, so the material magnetizes more readily. This is why materials with high permeability are used for magnetic cores in transformers and inductors—they guide and concentrate flux with less applied field.

Reluctance describes opposition to magnetic flux, not the ease of magnetization. Coercivity is about how strong a reverse field must be to demagnetize the material. Retentivity is the remaining magnetization after the external field is removed.