Question

Collect information regarding how the various magnets used in our day-to-day tasks are produced.

Answer 1

Production of magnets used in day-to-day tasks:

• Permanent magnets are made from a mixture of nickel, cobalt and iron. For example, alnico is a permanent magnet made from a mixture of aluminium, nickel and cobalt.
• Electromagnets are produced by passing an electric current through a coil of wire wrapped around a piece of soft iron (such as a nail). When the current flows, the nail becomes a magnet. When the current is switched off, the magnetism disappears.
• Magnets come in various shapes depending on their use — bar magnets, disc magnets, horseshoe magnets, ring-shaped magnets, cylindrical magnets and small button magnets.
• Magnetite is a natural magnet found as a rock. It was called a lodestone (leading stone) because it always settled in the north–south direction when suspended freely.
• Magnetic strips in ATM cards, credit cards, computer hard disks and audio/video tapes are made of thin magnetic material where information is stored.

Magnetic materials used for various purposes:

Use	Type of Magnet
Pin holder, cupboard door	Permanent magnet
Door bell, cranes, MRI machines	Electromagnet
Maglev train	Electromagnet (repulsion between train and rail)
ATM card, credit card	Magnetic strip (thin magnetic material)
Computer hard disk, audio/video tape	Magnetic material for data storage