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TOPIC: Magnetism
Meaning of magnet
When a magnet is put in a container filled with office pins or needles, by the time you bring the magnet out of the container; most of the pins or needles would have clung to it.
It shows that a magnet can attract needles and some other materials like cobalt, nickel, iron etc.
All the materials which can be attracted by magnets are called magnetic materials. The ability of a magnet to attract magnetic materials is called magnetism.
Lodestone
Lodestone also called magnetite is a black oxide of iron ore (Fe304).it has the ability to attract small pieces of iron and other pieces of magnetic materials. It is the original magnet, and large deposits of this substance were first discovered in Magnesia, in Asia, from where the name magnet was formed.
Law of magnetism
The law of magnetism states that like poles of a magnet repel each other, while unlike poles attract each other.
It implies that the north and south poles of a magnet attract each other while the north pole of a magnet repels the north pole of another magnet. Similarly, the south pole of a magnet repels the south pole of another magnet.
Magnetic poles and magnetic fields
If a bar magnet is tied in the middle and suspended in the air, when the bar magnet is made to swig freely, after some time it comes to rest in the north-south direction. If there is attraction, then the pole of the magnet beside the north-seeking pole of the standard magnet is the south-seeking pole.
Magnetic Field
Magnetic fieid refers to the region around a magnet where the effects of the force due to the magnet can be felt by magnetic materials.
Magnetic materials are substances that can be attracted by magnets e.g.iron, steel, nickel, cobalt, and certain alloys of iron. Magnets do not attract non-magnetic materials. Examples of non–magnetic materials include: rubber, glass, wood, etc.
A magnet has the ability to attract magnetic materials to itself over a distance with no contact between them. Therefore, the space around a magnet where this attraction is possible is the magnetic field. The magnet field around a magnet is made up of field lines.
MAGNETIC FIELD
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