How are permanent and temporary magnets useful?

Uses of Permanent Magnets

• Magnetic Compass: A permanent magnet is used as the needle in a compass and it helps in navigation by pointing in the north–south direction.
• Refrigerator Doors: Permanent magnets are fitted in the door lining so that the door closes tightly.
• Loudspeakers and Microphones: Permanent magnets are used in televisions, computers, speakers and microphones.
• Toys and Games : Many toys, puzzles, and magnetic boards use permanent magnets.
• Magnetic Locks and Closures: Used in bags, cupboards, and doors for easy locking.
• Credit Cards & ATM Cards: Magnetic strips are used in credit cards and ATM cards to store information.

Uses of Temporary Magnets

• Electromagnets in Cranes: Temporary magnets are used in cranes to lift heavy iron and steel objects in factories and scrap yards. When the current is switched off, the load is released easily.
• Electric Bells and Buzzers: Temporary magnets are used in electric bells such that the magnetism is produced only when electric current flows.
• Relays and Switches: Temporary magnets are used in electrical relays and switches to control circuits.
• Motors and Generators: Temporary magnets (electromagnets) are used in electric motors and generators where magnetism is required only during operation.
• Magnetic Separation: Temporary magnets are used to separate magnetic materials like iron from non-magnetic substances in industries.
• MRI and Scientific Instruments: Strong temporary magnets are used in scientific and medical equipment where magnetism must be controlled.