Hysteresis in a light bulb: connecting electricity and thermodynamics with simple experiments and simulations

A method for integrating energy conversion phenomena, nonlinear circuit behaviour and hysteresis into a simple laboratory activity is demonstrated. Current-voltage data for a flashlight bulb driven at various frequencies and amplitudes are measured and simulated. Non-ohmic behaviour and hysteresis are observed experimentally and reproduced numerically with a model that includes the temperature-dependent specific heat capacity and electrical resistivity of the filament. The phenomenological model and simple experimental design could be modified for a variety of audiences.