Which term describes the magnet's memory of its previous magnetization?

Which term describes the magnet's memory of its previous magnetization?

• A. Remanence
• B. Residual magnetism
• C. Saturation
• D. Remanence or Retentivity

Answer: (D)

The memory of a magnet’s previous magnetization is the leftover magnetization that remains after the external magnetizing field is removed. This is described by remanence (remanent magnetization) and by retentivity (the ability of the material to retain that magnetization). After you drive a material into saturation and then take away the field, the domains don’t all revert to random; some stay aligned, creating a residual, or remembered, magnetic state. That is why the best term here is Remanence or Retentivity—it captures both the amount of leftover magnetization and the material’s tendency to retain it. Saturation is just the maximum achievable magnetization under an external field, not the memory. Residual magnetism is essentially another way to describe leftover magnetization, but the combined term explicitly acknowledges both the remaining magnetization (remanence) and the remembering property (retentivity).

The memory of a magnet’s previous magnetization is the leftover magnetization that remains after the external magnetizing field is removed. This is described by remanence (remanent magnetization) and by retentivity (the ability of the material to retain that magnetization). After you drive a material into saturation and then take away the field, the domains don’t all revert to random; some stay aligned, creating a residual, or remembered, magnetic state. That is why the best term here is Remanence or Retentivity—it captures both the amount of leftover magnetization and the material’s tendency to retain it. Saturation is just the maximum achievable magnetization under an external field, not the memory. Residual magnetism is essentially another way to describe leftover magnetization, but the combined term explicitly acknowledges both the remaining magnetization (remanence) and the remembering property (retentivity).