The impedance of a resonance fed in parallel is huge theoretically infinite and is defined by the Q factor.

If you apply for say 40kv at 1ma and the tank have lets say 10 amps recirculating its clear that the XL is 40000ohms

and the Q is the relation of the input current to the recirculating current.

if you get 1 amps divided by 1ma you get Q factor of 1000

giving an impedance saw by the source as a 40MOhm resistor.

in series circuit the voltage will be the initial voltage(t) times the Q...