CK-12 Foundation
Ck 12: Physics Simulation: Galvanometer
[Free Registration/Login Required] Understand how the magnetic field generated by loops of current-carrying wire is used to create measuring devices like voltmeters and ammeters with this interactive simulation. A PDF worksheet and a...
PBS
Pbs Learning Media: Dc Circuit Builder
Play with resistors, light bulbs, wires, switches, a battery, voltmeters, and ammeters in this interactive circuit simulation.
Other
Univ.of Delaware: Real Batteries and Battery Testers
A discussion of various principles related to voltage. The operation of battery testers and voltmeters are explained. The importance of the internal resistance of a power source is discussed.