What is Magnetism?

Magnets

A magnet is an object that produces a magnetic field. The magnetic field makes the object magnetic therefore it is a magnet. Also a magnet has a north and a south pole. These poles are called the magnetic north and magnetic south. The compasses which we use aren't pointing exactly towards the geographical north and geographical south. They are actually pointing towards the magnetic north and magnetic south. The magnetic north and magnetic south are near the geographical north and geographical south but are not exactly on them.

types of magnets

There are 3 different types of magnets or 3 different main categories for magnets. They are permanent magnets, temporary magnets and electromagnets.

1. Permanent magnets- Of all the different types of magnets, the permanent magnets are the most commonly used. Permanent magnets are those types of magnets that once magnetized can retain their magnetism. The most common use of permanent magnet is used to hold notes and decorate the refrigerator door. They are used as hooks, in audio speakers, jewelry making, compass, etc. There are different types of permanent magnets such as:

  • Neodymium Iron Boron- These are really strong magnets that even if they are half-inch in diameter they are to able to lift ferromagnetic objects of several pounds. These are the most expensive of all the types of permanent magnets.
  • Samarium Cobalt- Similar to neodymium magnets, samarium cobalt is the strongest magnet out of the rare earth magnets. They too like the neodymium are very difficult to demagnetize.
  • Alnico - The alnico magnets are very strong magnets that are used commonly for science experiments. They are more expensive than the ceramic magnets.
  • Ceramic or Ferrite Magnets - These are strong magnets that are used for many lab experiments. They are used very commonly in schools.

2. Temporary magnets- Temporary magnets are those types of magnets that act like permanent magnets only when they are within a range of a strong magnetic field. As soon as these magnets are removed from the field, they lose their magnetism. The objects that act as temporary types of magnets are paperclips, iron nails, etc. Temporary magnets are used in telephones, electric motors and even in the production of electricity. There are many other uses of temporary magnets. 

3. Electromagnets- Electromagnets are different types of magnets that when you flow current into a tightly wound coil of wire around a nail and then it acts a like a magnet. When the current flows through the coil of wire around the nail (the nail usually has an iron core) it acts like a permanent magnet because of the domain theory. You should research on electromagnetism and the domain theory if you find electromagnetism interesting. These types of magnets and their uses include large cranes, lifting cables and rods during construction, television, computers, radios, video tapes, speakers and many more. 

Vocabulary

Ferromagnetic Objects-A ferromagnetic object is a material or substance which is highly magnetic. Examples include iron, nickel and cobalt.