Facts about Magnets

One of the first natural forces that humans discovered was most possibly magnetism, although it has been relatively recently that the full potential of the properties of magnetic substances have been realized. Devices using semiconductor technology which are so common these days could not be used without their magnetic components. The earliest magnets were referred to as lodestone or magnetite. Given below are some more fascinating facts about magnets.

A story goes that a shepherd from Crete named Magnes was the first to discover lodestone when his crook, which had an iron tip, was pulled towards a stone when he passed over it.

According to another story, Archimedes, the scientist of ancient Greece, is supposed to have pulled the nails out of enemy ships by using lodestone, which resulted in them sinking.

In the past, lodestone was used by sailors as an aid to navigation. They had discovered that when they suspended a piece of magnetite by a thread, it always pointed in a north-south direction.

All physical objects are made up of molecules, and the molecules of steel and iron have magnetic properties. According to the molecular theory of magnetism, all the molecules are aligned with their North Pole pointing in one direction and South Pole pointing in the opposite direction in a magnetized piece of steel or iron. Whereas, in a piece of steel or iron that is unmagnetized, the poles of the molecules point at various directions at random.

Magnets are of two main types: Permanent Magnets and Induced Magnets. Substances that are permanently magnetized are known as permanent magnets. Whereas, induced magnets are those that become temporarily magnetized when brought into proximity with a permanent magnet. For example, if you use a magnet to pick up a pin, the pin too will become magnetized and be able to pick up another pin. However, once the permanent magnet is removed, the pins lose their magnetic properties.

Each end of a piece of magnet is referred to as a pole, and the magnetism of each magnet is concentrated in its poles.

When the North Pole of one magnet is brought close to the South Pole of another magnet, they attract each other. Whereas if you bring a South Pole of one magnet close to the South Pole of another, or the North Pole near the North Pole of another, they repel each other.

Usually, magnets are made of steel or iron. However, special alloys of iron, nickel, copper, cobalt, and aluminum can be made into powerful magnets.

Hammering and heating a piece of steel or iron in a north to south direction can magnetize it. This is because the molecules get aligned in a north-south direction.

When an unmagnetized piece of steel or iron is rubbed with a magnet in a north to south direction, it gets magnetized. This is because the molecules get aligned in a north-south direction.

When an unmagnetized piece of steel or iron is placed beside a magnet, it becomes magnetized. This is because the molecules get aligned in a north-south direction.

Since the Earth itself acts as a huge bar magnet, having a magnetic north pole and south pole, when a piece of unmagnetized material is placed in a north to south direction, it results in magnetizing it due to the magnetic field of the Earth. This is because the molecules get aligned in a north-south direction.

Hammering a magnet can result in demagnetizing it because the molecules lose their north-south alignment and get arranged with their poles placed randomly in various directions.

When a magnet is heated in a hot flame, it will result in demagnetizing it because the molecules lose their north-south alignment and get arranged with their poles placed randomly in various directions.

An electromagnet is created when a piece of iron is coiled with a wire and electricity is passed through the coiled wire. This magnetizes the iron bar as long as the current is switched on, on switching off the electricity, it gets demagnetized.