Electricity and magnetism
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Magnetism. (2022). In Q-files Encyclopedia, Science, Electricity and magnetism. Retrieved from
https://www.q-files.com/science/electricity-and-magnetism/magnetism
"Magnetism." Science, Electricity and magnetism, Q-files Encyclopedia, 10 Feb. 2022.
https://www.q-files.com/science/electricity-and-magnetism/magnetism.
Accessed 19 Mar. 2024.
Magnetism 2022. Science, Electricity and magnetism. Retrieved 19 March 2024, from
https://www.q-files.com/science/electricity-and-magnetism/magnetism
Science, Electricity and magnetism, s.v. "Magnetism," accessed March 19, 2024.
https://www.q-files.com/science/electricity-and-magnetism/magnetism
Magnetism
Magnetism is a force that attracts some objects to other objects. Electricity can produce magnetism and magnetism can produce electricity. We cannot see the force of magnetism. But it is all around us since the Earth itself produces a magnetic field. A magnetic force affects mainly objects and substances that contain the metal iron; it attracts them. The force is present as a magnetic field around a magnet, which is itself usually made of iron. Magnets of different sizes and shapes have hundreds of uses, from holding notes on a refrigerator to being vital parts in electrical generators, motors and loudspeakers.
Magnetic poles
A magnet does not always attract another magnet. The magnetic force field is strongest at two areas called its poles. These are different from each other and known as north and south poles. The north pole of one magnet attracts the south pole of another magnet. But it pushes away or repels the other magnet’s north pole. The general rule is that unlike poles attract, like poles repel.
Earth's magnetic field
The lines of magnetic force in the Earth's magnetic field run between north and south poles as if there were a bar magnet placed at its centre. That bar magnet would be tilted at an angle of about 11° from the Earth's axis of rotation. The Earth's North Magnetic Pole is the point on the surface of the Northern Hemisphere at which the Earth's magnetic field causes the north pole of a compass needle to point vertically downwards into the Earth. Many scientists think that the Earth's magnetic field is created by electricity flowing deep inside the Earth itself. Giant movements of liquid metal in its outer core are responsible for generating this electricity.
Electromagnetism
The link between electricity and magnetism is called electromagnetism. Electricity and magnetism are so closely linked that one can produce the other. A magnetic field moving near a wire causes electricity to flow in the wire (1). An electric current flowing in a wire makes a magnetic field around the wire (2). Twist the wire into a coil and it produces a stronger magnetic field. It can be turned on and off by switching the electricity on and off. If a magnetic material is placed inside the coil an electromagnet is produced. Electromagnetism is the basis of electric motors and generators.
Consultant: Sharon Ann Holgate