Magnetism

Magnetism

Introduction Look around your home and try to find a magnet. A magnet is a metal object that sticks to other metals. You might have some magnets among your toys. There are probably magnets on your refrigerator. But did you know that there may be hundreds of magnets in your home? You cannot see most of them. But they are inside your television, telephone, and stereo. They are inside electric motors that power your blender and hair dryer. Computers are full of magnets. And all the electricity that runs these things comes from magnetism.

Magnetism and Maynets Magnetism is an invisible force. A force is anything that pushes, pulls, or moves an object. Magnetism is a special force that only pulls on some metals, such as iron. A magnet will not push or pull plastic or tin. Magnetism flows in one direction through a magnet, no matter what shape the magnet is. It flows in one end and out the other. The ends of a magnet are called magnetic poles. Every magnet has a north and a south pole. The force flows out the north pole and back in the south pole.

You can use two magnets to feel magnetism flowing. The north pole of one magnet will stick to the south pole of the other. Now, try to push the two north poles together. It feels almost like trying to connect two hoses that are both spraying water. The magnetic force pushes the north poles apart, because the magnetic forces are flowing against each other. Two north poles will always repel each other. So will two south poles.

The Earth's iron core is magnetic. The whole planet acts like a giant magnet. If you dangle a magnet by a string, one pole will point north and the other will point south. This is exactly how a compass works. This gave the north and south poles of a magnet their names.

Magnetic Field The magnetic force flows out the north pole of the magnet. Then, it loops around outside the magnet and flows back in the south pole. Magnetism flows through space in lines of force. The invisible shape formed by the lines of force around the magnet is called the magnetic field.