  This article presents a novel method for studying RLC series circuits using
two smartphones, one used as a signal generator and the other as an
oscilloscope. We measure the voltage at the external resistor as a function of
frequency when subjected to a sinusoidal electromotive force. The experimental
results demonstrate a remarkable agreement with the theoretical curve for the
voltage at the resistor and the resonance frequency, validating the accuracy of
the smartphone-based setup. The experiment fills the gap in educational
materials related to electrical circuits and provides a portable alternative to
traditional, expensive laboratory equipment.
