Magnetisme

Magnetism was first observed over 2500 years ago near the ancient city of Magnesia.

Magnets can be found in everyday objects like speakers, credit cards, compasses, and memory devices.

A bar magnet has a North and South pole. When an unmagnetized iron nail is brought in contact with it, it becomes magnetized.

Like poles of a magnet repel each other, while unlike poles attract each other.

A magnet's poles cannot be separated by breaking them into two pieces. Instead, smaller magnets, each with a north and south end, are obtained. Hence, magnetic monopoles are never observed.

In a navigation compass, the needle is a thin bar magnet suspended at its center.

The north pole of a compass is attracted close to the Earth's geographic North Pole.

Earth also acts like a huge bar magnet, with its magnetic south pole near the geographic North Pole and its magnetic north pole near the geographic South pole.

The axis of the Earth’s magnet and the geographical axis do not coincide. This deviation is called magnetic declination.