Physics magnetic field question?

How does the idea of magnetic fields arising from circulating currents relate to permanent magnets?

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  • Anonymous
    1 decade ago
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    The atoms in permanent magnets have internal magnetic moments, because of the way their electrons are in orbit (little currents). If you get all those little magnetic moments to add up, you get a macroscopic magnetic field (permanent magnet).

  • 1 decade ago

    Some of the electron orbitals in each molecule or atom are making small circulations around the atoms nucleus all cohered in the same direction in three dimensions. Conversely even macroscopic rotation of the proper (ferro)metallic structure will cause magnetism by rotation alone, by the gyroscopic reaction of (random) electron spins in the ferromagnetic metal to cohere the available unpaired electron spins to be in unity in three dimensions. This is why a revolving (AC) alternator field electromagnet can output power, even though the rotating electromagnet has not been energized. Remanent magnetism of the fields pole faces has often been used to explain why such an alternator can still output power even though the field has not been energized, but there are many arguments that can be used to show that this is instead the result of a gyroscpic reaction of the electron orbital spins to the macroscopic spin itself that produces the effect of that rotating magnetism.

  • 1 decade ago

    when current flows, a magentic field is generated. Permanent magent is made up of tiny subunits and they are aligned in a head-toe fashion. Electron (current) movement of all units is in the same direction and individual small magnetic fields join up to form a bigger magnetic field.

  • 1 decade ago

    F = BIL Where B is the Force of the Magnetic Filed in Teslas.

    B = Mew (Sub Zero) I / 2 Pie R

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  • 4 years ago

    When using Fb=qv cross B, remember q is negative for an electron. For practical purposes in this question, you can allow for this by treating v as if it is in the -i direction. There are different rules - for example you can you Fleming's Left hand rule for this or a right hand cross-product rule But if A = B cross C and you know A and (say) B, you can work out C if you are careful. (And you can always check your answer by testing that A and B then give the known direction of A.)

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