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Magnetic moment

In physics, the magnetic moment of an object is a vector property, denoted here as m, that determines the torque, denoted here by τ, it experiences in a magnetic flux density B, namely τ = m × B (where × denotes the vector cross product). As such, it also determines the change in potential energy of the object, denoted here by U, when it is introduced to this flux, namely U = −m·B.[1]

Notes

  1. V. P. Bhatnagar (1997). A Complete Course in ISC Physics. Pitambar Publishing, p. 246. ISBN 8120902025. 

    Origin

    A magnetic moment may have a macroscopic origin in a bar magnet or a current loop, for example, or microscopic origin in the spin of an elementary particle like an electron, or in the angular momentum of an atom.

    Macroscopic magnetic moment

    ===Microscopic magnetic moment===