What is the condition of maximum current in R-L-C circuit?

In an R-L-C circuit, maximum current occurs when the circuit is at resonance. This happens when the inductive reactance (XL) equals the capacitive reactance (XC), resulting in the impedance being minimized to the resistance (R) alone. At this point, the circuit can draw the maximum current from the power source, as the total impedance is at its lowest value. The resonant frequency can be calculated using the formula ( f_0 = \frac{1}{2\pi\sqrt{LC}} ).