What remains in a substance after the original magnetizing force has been removed?

What remains in a substance after the original magnetizing force has been removed?

• A. Reluctance
• B. Residual magnetism
• C. Permeability
• D. Hysteresis

Answer: (B)

Residual magnetism refers to the magnetism that remains in a material after the applied magnetic field has been removed. When materials are exposed to a magnetic field, they can become magnetized, meaning they align their internal magnetic domains in the direction of the field. Once the external magnetizing force is withdrawn, certain materials—typically ferromagnetic materials—retain some degree of magnetization, which is referred to as residual magnetism. This characteristic is crucial in various applications, such as in the creation of permanent magnets, where the material is magnetized and retains enough magnetism to maintain its magnetic properties without additional energy input. Understanding how residual magnetism works is important in fields involving magnetic materials and their applications. The other terms relate to different concepts in magnetism. Reluctance is a measure of the opposition that a material presents to the magnetic field, and permeability is a measure of how easily a material can become magnetized or conduct magnetic lines of force. Hysteresis describes the lag between the change in magnetization and the external magnetic field applied to a material, typically illustrated in the curve showing the relationships between magnetizing force and magnetization, but it does not directly describe what remains after magnetization ceases.

Residual magnetism refers to the magnetism that remains in a material after the applied magnetic field has been removed. When materials are exposed to a magnetic field, they can become magnetized, meaning they align their internal magnetic domains in the direction of the field. Once the external magnetizing force is withdrawn, certain materials—typically ferromagnetic materials—retain some degree of magnetization, which is referred to as residual magnetism.

This characteristic is crucial in various applications, such as in the creation of permanent magnets, where the material is magnetized and retains enough magnetism to maintain its magnetic properties without additional energy input. Understanding how residual magnetism works is important in fields involving magnetic materials and their applications.

The other terms relate to different concepts in magnetism. Reluctance is a measure of the opposition that a material presents to the magnetic field, and permeability is a measure of how easily a material can become magnetized or conduct magnetic lines of force. Hysteresis describes the lag between the change in magnetization and the external magnetic field applied to a material, typically illustrated in the curve showing the relationships between magnetizing force and magnetization, but it does not directly describe what remains after magnetization ceases.