Crocodile Clips

link to website

"Crocodile Physics is a simulator which lets teachers and students model physics experiments on-screen.

There are over 100 electrical components, with the basic ones available as pictures. Optical components include lenses, mirrors, prisms and screens. The powerful new force and motion parts let you investigate collisions, acceleration, velocity, energy & much more. You can also look at oscillations, SHM and hookes law. The waves simulation covers transverse & longitudinal waves in different media. Finally, the graphing tools let you plot results from your simulations."

this is aimed at Yrs 7-12 but may be useful for basic electrical principles and concepts.