The electrons in most objects spin in random directions, and their magnetic forces cancel each other out. Magnets are different because the molecules in magnets are arranged so that their electrons spin in the same direction. This arrangement and movement creates a magnetic force that flows out from a north-seeking pole and from a south-seeking pole. This magnetic force creates a magnetic field around a magnet.
Have you ever held two magnets close to each other? They don't act like most objects. If you try to push the two north poles or two south poles together, they repel each other. But if you put a north pole and a south pole together, the magnets will stick together because the north and south poles attract each other.
Just like protons and electrons—opposites attract in magnets. The properties of magnets are used to make electricity. Moving magnetic fields pull and push electrons. Metals such as copper and aluminum have electrons that are loosely held. Moving a magnet around a coil of wire, or moving a coil of wire around a magnet, pushes the electrons in the wire and creates an electrical current.
Electricity generators essentially convert kinetic energy the energy of motion into electrical energy. Electricity explained Magnets and electricity. What is energy? Units and calculators. Additionally, ferrimagnetism can be thought of as a combination of ferromagnetism and antiferromagnetism due to many similarities shared among them, but it still has its own uniqueness, according to the University of California, Davis.
When a wire is moved in a magnetic field, the field induces a current in the wire. Conversely, a magnetic field is produced by an electric charge in motion. A charge moving in a straight line, as through a straight wire, generates a magnetic field that spirals around the wire. When that wire is formed into a loop, the field becomes a doughnut shape, or a torus. According to the Magnetic Recording Handbook Springer, by Marvin Cameras, this magnetic field can be greatly enhanced by placing a ferromagnetic metal core inside the coil.
In some applications, direct current is used to produce a constant field in one direction that can be switched on and off with the current. This field can then deflect a movable iron lever causing an audible click.
This is the basis for the telegraph , invented in the s by Samuel F. Morse , which allowed for long-distance communication over wires using a binary code based on long- and short-duration pulses. The pulses were sent by skilled operators who would quickly turn the current on and off using a spring-loaded momentary-contact switch, or key. Another operator on the receiving end would then translate the audible clicks back into letters and words.
A coil around a magnet can also be made to move in a pattern of varying frequency and amplitude to induce a current in a coil. This is the basis for a number of devices, most notably, the microphone. Sound causes a diaphragm to move in an out with the varying pressure waves. If the diaphragm is connected to a movable magnetic coil around a magnetic core, it will produce a varying current that is analogous to the incident sound waves.
This electrical signal can then be amplified, recorded or transmitted as desired. Tiny super-strong rare-earth magnets are now being used to make miniaturized microphones for cell phones, Marsh told Live Science.
When this modulated electrical signal is applied to a coil, it produces an oscillating magnetic field, which causes the coil to move in and out over a magnetic core in that same pattern. The coil is then attached to a movable speaker cone so it can reproduce audible sound waves in the air. The first practical application for the microphone and speaker was the telephone , patented by Alexander Graham Bell in Although this technology has been improved and refined, it is still the basis for recording and reproducing sound.
See image below. If the majority of electrons in the atom spins in the same direction, a strong magnetic field is produced. The direction of the electrons spin determines the direction of magnetic field. If the same number of electrons in the atom spins in opposite directions, the electron spins will cancels out.
Thus, the magnetism will also be cancelled. A magnetic field is represented by lines of force extending from one pole of a magnet to the other pole. In everyday life, magnetic fields are most often encountered as a force created by permanent magnets, which pull on ferromagnetic materials such as iron, cobalt, or nickel, and attract or repel other magnets. Above image shows the lines of force between two magnets Right image shows force of repulsion between two north poles.
Left image shows lines of attractive forces between the north and south poles of magnets. You can think of a magnetic domain as a tiny magnet with a north pole and south pole. The properties of these magnets as stated above is due to the action of the spinning electrons in atoms. Groups of atoms join in such a way that their magnetic fields are all arranged in the same direction.
The region in which magnetic fields of individual atoms are lined up in the same direction is called a magnetic domain.
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