Question

Why does the magnetic field depend on moving charges only?

Answer 1

Explanation

1. A moving charged particle produces both an electric and a magnetic field.
2. This is because a charged particle will always produce an electric field, but if the particle is also moving, it will produce a magnetic field in addition to its electric field.
3. This magnetic field produced will depend on the inverse square of the distance to the charge $\left(r\right)$ as well as the velocity of the charge $\left(v\right)$.
4. The equation is given by

$\overrightarrow{B}\left(r\right)=\frac{q{\mu }_0}{4\mathrm{\pi }}\frac{\overrightarrow{v}\times \hat{r}}{r^2}$

which shows the dependence of velocity in the equation.

This shows if velocity is zero, then there is no magnetic field. i.e., the magnetic field is zero.