Magnetism
Physics · चुंबकत्व · 13 facts
1
Magnet: attracts iron/cobalt/nickel; North and South poles
2
Like poles repel; unlike attract; strongest at poles
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Earth is giant magnet; compass shows N-S direction
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Electromagnet: current+coil+iron core; temporary
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Uses: bells, cranes, MRI, speakers, motors
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Oersted(1820): current produces magnetic field around conductor
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Fleming Left Hand: force on conductor in field (Motor)
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Fleming Right Hand: induced current direction (Generator)
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Motor: electrical to mechanical; Generator: mechanical to electrical
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Faraday Law: changing magnetic field induces EMF
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Field lines: N to S outside; never cross
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Magnetic materials: ferromagnetic(Fe), paramagnetic(Al), diamagnetic(Cu)
13
Breaking magnet gives two complete magnets with N and S poles each