# How do moving charges change the evolution of a magnetic field?

Jun 12, 2016

The relationship between moving charges and magnetic field is regulated by the Ampère's law (that is one of the Maxwell equations).

$\setminus \nabla \setminus \times B = \setminus {\mu}_{0} J + \setminus {\mu}_{0} \setminus {\epsilon}_{0} \frac{\setminus \partial E}{\setminus \partial t}$.

This equation says that the magnetic field is generated by a current $J$ or an electric field that changes in time $E$ (if the electric field is constant, its time derivative is zero).