TANK CIRCUIT

A TANK CIRCUIT consists of a capacitor and an inductor in PARALLEL
The inductors voltage increases as the capacitor slowly discharges.  Once the capacitor is totally drained, the electromagnetic field surrounding the Inductor begins to collapse.  This voltage drop will feed into the capacitor and the capacitor begins to store this charge in its electrostatic field.

The capacitor will now sense that the inductor has no energy and will begin to discharge its current through the inductor.  This cycle continues.

In a PARALLEL Resonant circuit, and given a small amount of resistance in any realistic circuit, as the capacitor discharges, the current in the Inductor increases. Therefore the net result in such a circuit is that zero current is drawn from the source (be it a battery or a transistor). As one component draws current, the other returns it to the source. Now in a parallel circuit, voltage is the same across all branches.

So if the reactance is the same across a capacitor and the same across the inductor, then the current is the same across both components. So the net affect is 0 amps

Now R = V/I so we have a VERY HIGH IMPEDANCE in a parallel circuit. This is in contrast to a series LC circuit, where the impedance is low and hence high current.