Magnet Basics

Below you will find some commonly asked questions about magnets and magnetism. If you don�t find the answers you�re looking for, please contact us.

Questions & Answers

What is a magnet?
What is a magnetic field?
What is magnetism?
What are magnets attracted to?
What are some uses for magnets?
What are permanent magnets made of?
How are magnets made?
What are magnetic poles? What is the difference between the north and the south pole of a magnet?
Is there a simple way to tell which end of a magnet is the north pole?
Is it true that magnetic fields are stronger closer to the magnets themselves?
What is the difference between permanent magnets and electromagnets?
Are permanent magnets really permanent?
Do magnets get weaker? How?
Can magnets be made stronger?
What kind of magnets are the strongest?
How do I repair my de-magnetized compass?
Interesting Facts

What is a magnet?
At its most basic level, a magnet is an object that is made of materials that create a magnetic field. Magnets have poles, at least one north pole and one south pole.Top

What is a magnetic field?
A magnetic field is the region in space where a magnetic force can be detected. The strength and the direction of a magnetic field can be measured using proper meters designed for magnetism.Top

What is magnetism?
Magnetism is the force of attraction or repulsion between substances made of certain materials, such as iron, nickel, cobalt, and steel. The force of magnetism, simply put, is due to the motion of electric charges.Top

What are magnets attracted to?
Magnets are attracted to three types of metals: nickel, iron, and cobalt.Top

What are some uses for magnets?
Magnets are used in most electronic devices and anything that has a motor uses magnets. TV�s, computers, fax machines, microwave ovens, all operate with magnets. Magnets are used to keep refrigerator doors closed, mounted on trucks that clean roadways, placed in cows’ stomachs to catch metals, applied in medical devices to create a magnetic picture, used to slow down roller coasters and subways, as well as in countless other devices. As a matter of fact, new uses of magnets are found almost everyday.Top

What are permanent magnets made of?
Today�s permanent magnets are made of alloy materials, which include Aluminum-Nickel-Cobalt (AlNiCo), Neodymium-Iron-Boron (NdFeB), Samarium-Cobalt (SamCo), and Strontium-Iron (also called Ferrite or Ceramic). Both Neodymium and Samarium are members of the rare earth elements. Neodymium magnets are also called the super strong magnets in the industry, since they may be made of the most powerful grade in strength available at the present time.Top

How are magnets made?
Magnets are commonly made from materials that contain nickel, iron, or cobalt. When these materials are exposed to an external magnetic field, the structure of the material is changed on a microscopic level. The molecules are rearranged into lines and the process is called polarization. When enough of the material is polarized, it becomes a magnet.Top

What are magnetic poles? What is the difference between the north and the south pole of a magnet?
Each magnet has two poles, which are the end points of the magnetic field around the magnet. When suspended or allowed to rotate freely, magnets orient themselves in a north-south direction, which is almost but not exactly aligning to the geographicall north-south direction of the earth. The end of a magnet that points to the north is called the north pole, whereas that to the south called the south pole.Top

Is there a simple way to tell which end of a magnet is the north pole?
Both poles of a magnet look the same. However, if you place a compass near a magnet, the needle that normally points toward the north pole of the earth moves in the direction of the magnet�s south pole.Top

Is it true that magnetic fields are stronger closer to the magnets themselves?
Yes. The strength of magnetic fields diminishes with distance. This phenomenon is described mathematically with exponential equations.Top

What is the difference between permanent magnets and electromagnets?
Permanent magnets produce a magnetic field without the need for any external source of power. An electromagnet generates a magnetic field only when an electrical current runs through it.Top

Are permanent magnets really permanent?
Magnets generally retain their magnetism unless they are stored near power lines, other magnets, and high temperatures. Over time, magnet materials lose a very small amount of magnetism. For example, Samarium Cobalt magnets may lose about 1% of their magnetism in ten years.Top

Do magnets get weaker? How?
Several factors can weaken the magnetism in a magnet. If a magnet is stored close to heat, strong electrical currents, other magnets, or radiation, it can lose its strength. Additionally, high humidity can corrode neodymium magnets.Top

Can magnets be made stronger?
Once a magnet is fully magnetized, it cannot be made any stronger.Top

What kind of magnets are the strongest?
Rare earth magnets (e.g., NdFeB and SamCo) are the strongest.Top

How do I repair my de-magnetized compass?
If your compass becomes demagnetized (pointing to the wrong directions), you may place the South Pole of a bar magnet directly on top of the compass needle. Next, slowly slide the bar magnet along the red side of the needle, toward the pointy end, and then down the side of the compass. Once you pull the magnet away, your compass should be re-magnetized.Top

Interesting Facts

All animals including humans have small magnetite crystals in their brains. Scientists believe that animals may navigate or migrate by sensing the pull of the crystals towards the earth�s magnetic poles.Top

The earth is a big magnet. Liquid metals deep within the earth create convection currents which in turn create the magnetic force. It is believed that the magnetic force surrounding the earth makes life possible. Without the �magnetic force field� too much energy would reach us from the sun and would wipe out our atmosphere.Top

All electricity is generated from magnets at the present time. When a magnet is spun inside a coil of wire, electrons start to flow in the wire. Most power plants use various kinds of fuels to spin magnets.Top

CMS MAGNETICS, INC.
1839 Wall Street | Garland, TX 75041 | Toll Free: (866) 342-1300 | Local: (972) 516-0692 | Fax: (972) 516-0697 | sales@cmsmagnetics.com
Copyright 1999 – 2013 by CMS Magnetics, Inc. All Rights Reserved.