Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsElectric Field Lines Due to a Collection of Point Chargeshttp://demonstrations.wolfram.com/ElectricFieldLinesDueToACollectionOfPointCharges/]]>http://demonstrations.wolfram.com/ElectricFieldLinesDueToACollectionOfPointCharges/