Problem 3.353

A thin wire ring of radius \(a\) carrying a charge \(q\) approaches the observation point \(P\) so that its centre moves rectilinearly with a constant velocity \(v\). The plane of the ring remains perpendicular to the motion direction. At what distance \(x_{m}\) from the point \(P\) will the ring be located at the moment when the displacement current density at the point \(P\) becomes maximum? What is the magnitude of this maximum density?