A Capacitors Experiment for Introductory College Physics Using Logger Pro

An experiment has been designed for introductory-level physics students to study the behavior of capacitors using Logger Pro. The students connect the current probe in series with a capacitor and a resistor of several hundred ohms. The LabQuest interface allows them to see the current as a function of time. From this, they can use the software to integrate over the time interval and obtain the total charge that builds up on the capacitor. After repeating this process for multiple voltage values, they plot charge vs. voltage and use the slope of the graph to obtain a value for the capacitance. Students obtain the capacitance for two capacitors individually, together in series, and together in parallel. Random noise is significant at low levels of current, but agreement with DMM-measured values of the capacitances within 10% is readily achievable. In addition, students can observe when a capacitor breaks down and learn how to correctly interpret the result.