Pre-Quantum Electrodynamics
Torques and Forces on Magnetic Dipolesemsm.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):
\[ {\bf F} = {\boldsymbol \nabla} ({\bf m} \cdot {\bf B}) \label{Gr(6.3)} \]

Created: 2022-02-21 Mon 10:33