In a AC circuit with just a capacitor or inductor, reactance is the impedance of the component, and in a non-complex RLC circuit you can just find the total impedance with vector addition (Ztot = sqrt(R^2 + (Xl – Xc)^2), but in a complex ac circuit how do you find the impedance of a single component?

Say i want to find the impedance of components C2, C3, L2 and L3 in the circuit below.

^{simulate this circuit – Schematic created using CircuitLab}

## Best Answer

These 4 elements can't be combined to find an equivalent impedance because of the presence of R2.

If you want to find the equivalent impedance of all 5 elements, including R2, you will just do the same math you would if they were all resistors, but use their complex impedance values instead of real-valued resistances.

This particular subcircuit can't be solved using just parallel and series combinations, so you'll need to either use more complex combinations like the wye-delta transform or just use KVL or KCL to form equations and solve the circuit.