Ramo-Shockley relation for a series <Emphasis Type="Italic">RCL</Emphasis> circuit

The current induced by the passage of an external point charge through a plane vacuum capacitor in an RCL circuit free of current (voltage) sources is calculated. The case is also analyzed when an internal point charge is emitted by one of the capacitor plates, moves to the other plate, and is absorbed by it. A technique is proposed to measure the internal charge and its velocity component perpendicular to the capacitor plates in a passive RCL circuit.