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ChemGuy
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Does conservation of energy apply to magnetism?
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Do magnets ever "wear" out. Do they ever lose their magnetism?
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Do magnets ever "wear" out. Do they ever lose their magnetism?
ChemGuy said:Do magnets ever "wear" out. Do they ever lose their magnetism?
Huh? How does thermal motion destroy the alignment of the domains?Shooting Star said:The so called permanent magnets eventually do wear out, i.e., their strength slowly lessens. How fast this happens depends on how it has been treated. If you heat it, or drop it, or keep it near a strong electrical current, the faster it wears out. That is why you have "keeper" of a magnet, which is nothing but a piece of ferromagnetic material placed so as to connect the poles of the magnet, and keeping the "magnetic lines of force" closed.
Random thermal motion of the molecules tend to destroy the alignment of the domains. A powerful magnet is in a highly ordered state, and the thermal motion tends to destroy that. As with every other process in nature, the entropy increases. In fact, above the Curie point of a metal, a magnet cannot be formed at all due to thermal motion of the molecules.
pmb_phy said:Huh? How does thermal motion destroy the alignment of the domains?
The superconducting magnets used for MRIs in hospitals have a lot of stored magnetic energy, even though they are not connected to any power supply. the stored energy isChemGuy said:Does conservation of energy apply to magnetism?
Conservation of energy is a fundamental law of physics that states energy cannot be created or destroyed, only transformed from one form to another. This also applies to magnetism, as magnetic fields contain energy that can be converted into other forms, such as electrical energy.
Magnetic fields play a crucial role in energy conservation because they can store and transfer energy. When a magnet moves in a magnetic field, it can induce an electrical current, which is a form of energy. This demonstrates the conversion of energy between magnetic and electrical forms.
Yes, magnetic energy can be conserved in a closed system, as long as there is no external influence that can change the magnetic field. This is similar to the conservation of other forms of energy, such as mechanical or thermal energy, in a closed system.
Yes, conservation of energy applies to permanent magnets. While permanent magnets may seem to have an endless supply of energy due to their ability to attract and repel without apparent loss of strength, they do not violate the law of conservation of energy. The energy in a permanent magnet comes from the alignment of its atoms, which can be changed by external forces, resulting in a decrease in the magnetic field and energy.
The conservation of energy in magnetism has a significant impact on everyday life. Many modern technologies, such as generators, electric motors, and transformers, rely on the conversion of energy between magnetic and electrical forms. Additionally, the Earth's magnetic field plays a crucial role in protecting us from harmful solar radiation, which is a result of the conservation of energy in the Earth's core.