MAGNETISM Magnetic Poles A magnet is any substance that attracts the element iron or anything with iron in it. All magnets have opposite ends or poles. These are referred to as the north and south poles. Because similar poles repel each other and opposite poles attract each other, magnets can either repel or attract each other. The degree to which they do this depends on the magnetic force of the magnet. In addition, because of polarity, all magnets will point toward the magnetic north pole of the earth. While the greatest magnetic force is at the poles, there is some degree of magnetism all around a magnet. This is called the magnetic field. LESSON CHECKPOINT: What is the difference between magnetic force and magnetic field? Inside a Magnet Deep inside the magnet are the clusters of atoms that are responsible for magnetic properties. These clusters are called magnetic domains. In a domain, the atoms line up with similar magnetic fields. Substances in which all or most of the domains are lined up in the same direction are said to be magnetized. Substances in which these domains line up in different directions are considered to be non magnetic. LESSON CHECKPOINT: What are magnetic domains? © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Earth's Magnetism The earth acts like a giant magnet. While the magnetism of the earth is difficult to explain, there is no question that it has two opposite poles and a strong magnetic field. While the earth has a geographic north and south pole, it also has a magnetic north and south pole. Through the years, these poles have shifted back and forth and seem to drift some every year. The chart below provides data for the movement of the magnetic north pole between 1948 and 2001. LESSON CHECKPOINT: How is the Earth like a magnet? © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.