GEOLOGY

Detailed explanation-1: -The magnets which can possess magnetic properties for a short interval of time are known as ferromagnets.

Detailed explanation-2: -Temporary magnets are made of soft metals that are magnetised only when exposed to a permanent magnetic field or an electric current. When they come into contact with a magnetic field, they become magnetized. When the magnetic field is removed, they gradually lose their magnetism.

Detailed explanation-3: -Temporary magnets retain magnetism only for a short period of time.

Detailed explanation-4: -A temporary magnet can lose its magnetization in less than 1 hour. Neodymium magnets lose less than 1% of their strength over 10 years. Permanent magnets such as sintered Nd-Fe-B magnets remain magnetized indefinitely. Iron magnets need a keeper to complete the circuit and preserve the magnetism.