Pre-Quantum Electrodynamics

Torques and Forces on Magnetic Dipoles emsm.msm.m.fdi

Torque on magnetic dipole:

\[ {\bf N} = {\bf m} \times {\bf B} \label{Gr(6.1)} \]

Tends to align magnetic dipoles with field. Accounts for paramagnetism. Exact for extended dipole in uniform field, or for point dipole in non-uniform field. Similar to electric analogue, \ref{Gr(4.4)}, \({\bf N} = {\bf p} \times {\bf E}\).

In a non-uniform field: (to be done in Problem 6.4):

\[ {\bf F} = {\boldsymbol \nabla} ({\bf m} \cdot {\bf B}) \label{Gr(6.3)} \]


Author: Jean-Sébastien Caux

Created: 2022-02-08 Tue 06:55

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