Magnetic poles exist in pairs. Comment.

(i) Magnet: A material (substance) which attracts pieces of iron or steel.

(ii) Magnetite: An ore of iron which has magnetic properties.

(iii) A magnet which occurs in nature and is not made by any artificial means is called a natural magnet.

(iv) A substance to which properties of a magnet are imparted by artificial means is called an artificial magnet.

2. Magnetic and Non-Magnetic materials:

(i) The substances which are strongly attracted by a magnet and can be easily magnetised are called magnetic substances.

(ii) The substances which are not attracted by a magnet and cannot be magnetised are called non­magnetic substances.

3. Poles of Magnet:

(i) North pole of a magnet: The end of a freely suspended magnet, which points towards the geographic north pole.

(ii) South pole of a magnet: The end of a freely suspended magnet, which points towards the geographic south pole.

4. Finding Directions:

(i) The two most important properties of a magnet are its attractive property and its directive property.

(ii) A magnetic compass is a freely suspended magnetic needle, placed in an aluminium box at the base of which are marked geographic directions. It is used by the sailors and navigators for finding directions at a given place.

(iii) A freely suspended magnet always points in the north-south direction.

5. Making Your Own Magnet: 

(i) An unmagnetised piece of iron can be magnetised by rubbing it with a permanent bar magnet.

6. Attraction and Repulsion Between Magnets:

(i) Similar poles of magnets repel each other, whereas opposite poles of magnets attract each other.

(ii) A permanent magnet loses its magnetism if heated or hammered or rough handled.

(iii) Bar magnets are stored in pairs, separated from one another by a wooden partition and iron keepers are placed at their ends.

(iv) Electronic devices get damaged by strong magnets. Such devices should be kept away from strong magnets.