Key Points

Magnets can be natural, like lodestones, or artificial, made from materials such as iron. Artificial magnets come in various shapes like bar magnets, ring magnets, and U-shaped magnets.

Magnetic materials are substances that are attracted towards a magnet. Examples include iron, nickel, cobalt, and some of their combinations with other metals.

Non-magnetic materials are substances that are not attracted towards a magnet. Examples include wood, plastic, glass, and rubber.

Every magnet has two poles: a North pole and a South pole. The magnetic attraction is strongest near these ends of the magnet, as observed with iron filings.

The poles of a magnet always exist in pairs. It is not possible to obtain a magnet with a single North pole or a single South pole, even if the magnet is broken into smaller pieces.

A freely suspended magnet always comes to rest along the North-South direction. This property is fundamental for finding directions.

The end of a freely suspended magnet that points towards the North direction is called the North-seeking pole or North pole. The other end, pointing towards the South direction, is called the South-seeking pole or South pole.

A magnetic compass is a small device containing a freely rotating magnetic needle. Its needle aligns with the Earth's magnetic field, indicating the North-South direction.

The Earth itself behaves like a giant magnet, which is why a freely suspended magnet or compass needle always aligns itself in the North-South direction.

When two magnets are brought close to each other, their unlike poles (North pole of one and South pole of the other) attract each other.

When two magnets are brought close to each other, their like poles (North-North or South-South) repel each other. Repulsion is a sure test for identifying a magnet.

The magnetic effect can act through non-magnetic materials such as wood, cardboard, plastic, and glass. This means the magnetic force is not blocked by these materials.

An iron object, such as a sewing needle, can be temporarily magnetized by repeatedly stroking it in one direction with one pole of a permanent magnet.