Random sampling of an alternating current source: A tool for teaching probabilistic observations.

We describe an undergraduate-level experiment that demonstrates the role of probabilistic observations in physics. A capacitor and a dc voltmeter are used to randomly sample an ac voltage. The resulting probability distribution is analyzed to extract information about the source. Different characteristic probability distributions arising from various ac waveforms are calculated and experimentally measured. We show how limited information about the waveform can be extracted from the voltage probability distribution, which is used to reconstruct the waveform for the special case of a sinusoidal waveform. The results are also compared with a simulated data sample. The experiment can be used as a pedagogical tool to teach probabilistic measurements and their manipulations. [ABSTRACT FROM AUTHOR]