Explainer Derives Impedance of Resistors, Capacitors, and Inductors in AC Circuits

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A DEV Community article systematically examines how resistors, capacitors, and inductors oppose alternating current, using phasor methods and frequency-domain analysis. It defines impedance as a complex quantity combining resistance, which dissipates energy, and reactance, which stores and releases it. The author derives the impedance of a resistor as a purely real value independent of frequency, with voltage and current in phase. For a capacitor, the piece shows impedance is purely imaginary and inversely proportional to frequency, with current leading voltage by 90 degrees and infinite impedance at DC. The article frames these results as a basis for understanding filters, resonance, and AC circuit analysis.

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ProgrammingDEV Community ·

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