Problem 3.354

A point charge \(q\) moves with a non-relativistic velocity \(\mathrm{v}=\) const. Applying the theorem for the circulation of the vector \(\mathbf{H}\) around the dotted circle shown in Fig. \(3.97,\) find \(H\) at the point \(A\) as a function of a radius vector \(\mathbf{r}\) and velocity \(\mathbf{v}\) of the charge.