Note for Reader’s :- the bold letters (e.g. B ) represents vector B.
An electron moving around the nucleus of an atom is equivalent to a magnetic dipole.
The torque τ on electron produces a change dL in angular momentum L in a time dt. The change dL is perpendicular to L.
Thus, the angular velocity of Larmor’s precession is equal to product of the magnitude of magnetic field, and the ratio of magnetic moment to magnitude of angular momentum.
Importance : This theorem is of considerable importance in atomic structure as it enables an easy calculations of energy levels in presence pf external magnetic field.
This is Larmor’s Precession. You can ask any question related to this post in comment section.