battery_3D_down.png source=PhET author=Noah P
battery_3D_up.png source=PhET author=Noah P
probe_3D_black.png source=PhET author=Noah P
probe_3D_field.png source=PhET author=Noah P
probe_3D_red.png source=PhET author=Noah P
sliderKnob.png source=PhET notes=copied from faraday
sliderKnobHighlight.png source=PhET notes=copied from faraday
voltmeter.png author=PhET notes=copied from circuit-construction-kit vm3.gif