We have shown that a current loop (i) produces a magnetic field and
behaves like a magnetic dipole at large distances, and
(ii) is subject to torque like a magnetic needle This led Ampere to suggest
that all magnetism is due to circulating currents This seems to be partly
true and no magnetic monopoles have been seen so far However,
elementary particles such as an electron or a proton also carry an intrinsic
magnetic moment, not accounted by circulating currents