Using a digital voltmeter and a smartphone camera to investigate the RC circuit

This paper presents a simple and accessible method to investigate the charging and discharging behaviour of a capacitor in a resistor–capacitor (RC) circuit. The technique simply requires a digital voltmeter, a stopwatch and a camera. A video using a high-speed smartphone camera captures simultaneously the readings of both the voltmeter and the stopwatch in order to record the temporal behaviour of the voltage across the capacitor. A good agreement between experimental results and theoretical models is observed.