What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?
Why In a parallel LC tank at resonance, the inductive and capacitive branch currents are equal in magnitude and opposite in phase, so they largely cancel at the terminals. The energy sloshes back and forth between L and C, producing a circulating (tank) current that is roughly Q times the current drawn from the source, so it reaches its maximum at resonance. Meanwhile the impedance seen by the source is maximum and the line current is minimum.
Watch out The choice saying minimum describes the current drawn from the external source, not the current circulating inside the tank; the formula choices are versions of the resonant frequency equation, not a current.
Parallel resonance: line current minimum outside, circulating current maximum inside the tank (about Q times bigger).