This simulation shows charges with various properties moving in a magnetic field. The direction of the magnetic field is shown by the pink arrows with X indicating a field pointing into the screen and o indicating a field pointing out of the screen. The force on each charge is shown by a vector in black.
You can restart the current simulation by clicking 'Reset' and then 'Play'.
Start the simulation with a single charge which is not moving initially. The field in this case points to the right. Describe what happens. Why doesn't the charge move? Describe what would have happened in this case had it been an electric field instead of a magnetic field.