Charge and Energy Stored in a Capacitor

摘要

Using a data-acquisition system, the charge and energy stored in a capacitor are measured and displayed during the charging/discharging process. The experiment is usable as a laboratory work and/or a lecture demonstration.The charge Q and energy E stored in a charged capacitor depend on the voltage V applied to it: Q = CV, E = 1/2CV~(2'1'2) The energy stored in a charged capacitor can be determined with a calorimeter equipped with a heater and a thermometer.~(3-5) The capacitor is discharged through the heater, and the energy stored is determined from the temperature rise of the calorimeter; a calibration is therefore needed for establishing a relation between the two quantities.