In an ac circuit when the supply voltage frequency is equal to the resonant frequency, the current
Answer Details
In an AC circuit, when the supply voltage frequency is equal to the resonant frequency, the current is in phase with the supply voltage. This means that the current and voltage signals reach their maximum and minimum values at the same time and change direction at the same time. There is no phase shift between them. This is because at resonant frequency, the inductive reactance of the inductor and the capacitive reactance of the capacitor are equal in magnitude but opposite in sign. This results in cancelling out each other's effect and hence the circuit impedance becomes purely resistive. Therefore, the current flowing in the circuit is limited by the resistance of the circuit alone and is in phase with the voltage across the circuit.