Magnets have a field around them that attract metals such as iron, steel and nickel. Magnets are used for a variety of purposes and have application in every walk of life. In this article we will discuss the principle behind magnetism.
Atomic magnetism
There are very elements that are naturally attracted towards magnets. While the rest of the metals don’t have any magnetic properties, or aren’t attracted towards magnets. As long as a magnetic substance is close to another magnet, they temporarily acquire the magnetic properties. When alloys of certain materials are used, they can be used as extremely good permanent magnets.
We can magnetize a substance by flowing constant electricity through it. When electricity flows through an object, a bunch of electrons constantly moves around the object giving the object magnetic properties.
We are all aware of the nucleus of an atom. The nucleus of an atom is surrounded by protons, and several electrons move around it. These electrons work within the quantum mechanics’ principles to form a magnet. There are various magnetic domains that may be found.
Magnetic domains
• Quantum mechanical forces hold the magnetic moments in the neighboring atoms parallel.
• The atoms which have magnetic characteristics are grouped under domains. There is a separate north and south pole for each domain.
• The domains have a random orientation in non-magnetized ferrous substances. However, there is still the presence of the magnetic fields.
• An external magnetic field induces magnetism in the domains so that they get aligned and their movements add and line up along the field.
Softer materials like iron have a larger field of alignment. However, the alignment in this case is highly temporary. For harder substances like Alnico, a greater and stronger field needs to be applied to induce magnetism but once induced; they behave like magnets even after removal of the external field.
Magnetic poles
When a bar magnet is freely suspended by a thread its ends tend to point to the geographic poles. The magnetic poles are similar to the geographic poles. The magnetic pole of a magnet tends to repel another magnet if the same pole of another is brought near it. On the other hand, unlike poles attract each other.
The earth too has its own magnetic field. The poles of the earth, viz; the north and the south are quite a distance away from the magnetic poles of the earth, but they can be generalized.
Ferrous substances of various shapes and sizes can be magnetized to serve numerous purposes. One of the mostly used magnets is the horse shoe magnet. It looks like a horse and has both poles facing the same direction. They are kind of electromagnets and perform heavy-duty tasks. Magnets can be found in mobile phones, transistor, and television and likewise, in many electronic instruments.
While normal magnets are temporary, electromagnets are made by passing huge amounts of electricity and are very powerful. Magnets also help in showing directions and are used for navigational purposes.
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