current

phet.colorado.edu

See how the equation form of Ohm's law relates to a simple circuit. Adjust the voltage and resistance, and see the current change according to Ohm's law.

phet.colorado.edu

Experiment with an electronics kit! Build circuits with batteries, resistors, ideal and non-Ohmic light bulbs, fuses, and switches. Determine if everyday objects are conductors or insulators, and take measurements with an ammeter and voltmeter. View the circuit as a schematic diagram, or switch to a lifelike view.

phet.colorado.edu

Explore the interactions between a compass and bar magnet. Discover how you can use a battery and coil to make an electromagnet. Explore the ways to change the magnetic field, and measure its direction and magnitude around the magnet.