An improved equipotential lab for parallel plates

The typical equipotential lab involves students sampling points in an electrode configuration: they move the probe around until they find a series of points with the same potential. Other authors have highlighted some difficulties with the traditional lab approach: most do not allow real-time visualization of equipotential lines, and students often seem to rely conceptually on single point charge equipotential models or Coulomb’s laws. I propose a different approach to the parallel plate lab: Students are directed to set up a grid of equally spaced points between parallel plates. Students measure and record probe voltages in a spreadsheet and analyze voltages as a function of x and y. I demonstrate typical results and briefly discuss possible extensions.