What is the ability of a material to retain its magnetism called?

• A. Permeability
• B. Retentivity
• C. Susceptibility
• D. Inductance

Answer: (B)

The ability of a material to retain its magnetism after the external magnetic field has been removed is referred to as retentivity. This characteristic is crucial in magnetic materials, particularly in applications such as permanent magnets, where the material must keep the magnetization for an extended period to function effectively.

Retentivity indicates how well a material can maintain its magnetic properties, which is essential in various electrical and mechanical applications. For example, materials with high retentivity, such as certain types of steel, are commonly used in the manufacture of permanent magnets and magnetic storage devices because they can hold a magnetic charge without requiring continuous power.

In contrast, permeability relates to how easily a material can become magnetized when exposed to an external magnetic field. Susceptibility measures how responsive a material is to an applied magnetic field, while inductance refers to the ability of a conductor to induce electromotive force due to a change in current. Each of these concepts addresses different aspects of magnetism but does not specifically define the lingering magnetic property itself, which is captured by the term retentivity.