Differentiate between permanent and temporary magnets.

Property Permanent Magnets Temporary Magnets
Definition Permanent magnets are materials that retain their magnetism for a long time without needing an external magnetic field. Temporary magnets are materials that only exhibit magnetic properties when placed in a magnetic field and lose their magnetism once the field is removed.
Magnetism Permanent magnets have intrinsic magnetism, meaning they are always magnetized. Temporary magnets only become magnetized when influenced by an external magnetic field.
Types of Materials Made from materials such as steel, iron, cobalt, and nickel that retain their magnetic properties over time. Made from materials like soft iron or ferromagnetic materials that easily become magnetized in the presence of a magnetic field.
Magnetization The magnetic properties of a permanent magnet are stable and do not change under normal conditions. The magnetization is temporary and can be easily lost when the external field is removed.
Duration of Magnetism Permanent magnets retain their magnetism for a long time, even indefinitely, unless subjected to extreme conditions like heating or physical impact. Temporary magnets only exhibit magnetism while within the external magnetic field. Once the external field is removed, they lose their magnetization.
Examples Bar magnets, horseshoe magnets, magnetic compass needles, and neodymium magnets. Electromagnets, nails magnetized by rubbing, and a piece of iron near a strong magnet.
Strength of Magnetism Permanent magnets have a strong, constant magnetic field. Temporary magnets have a weaker, variable magnetic field that diminishes when the external field is removed.
Response to External Fields Permanent magnets do not require an external magnetic field to maintain their magnetism. Temporary magnets lose their magnetism once the external magnetic field is removed.
Applications Used in applications where constant magnetic properties are required, such as in motors, generators, magnetic storage devices, and compasses. Used in situations where temporary magnetism is needed, such as in electromagnets (used in lifting heavy objects or in electric bells) and magnetic relays.
Retentivity Permanent magnets have high retentivity, meaning they can retain their magnetism well over time. Temporary magnets have low retentivity, meaning they quickly lose their magnetism once the external field is removed.
Ease of Magnetization Permanent magnets are difficult to magnetize and require a process like heating or applying a strong magnetic field. Temporary magnets are easy to magnetize and can be magnetized by placing them in an external magnetic field.

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