Four charged particles are are randomly placed using JavaScript and the field lines are
calculated. You can click-drag any of these particles. Start
<script language="JavaScript">
function field(){
document.EField.setDefault();
document.EField.setShowTime(0);
document.EField.setNoDrag(0);
document.EField.setShowForce(0);
document.EField.setChargeRGB(0,0,0);
document.EField.setChargeLabel("1");
document.EField.addCharge(0.25+Math.random(),0.25+Math.random(),3);
document.EField.setChargeLabel("3");
document.EField.addCharge(0.25+Math.random(),0.25+Math.random(),-1);
document.EField.setChargeLabel("2");
document.EField.addCharge(0.25+Math.random(),0.25+Math.random(),1);
document.EField.setChargeLabel("4");
document.EField.addCharge(0.25+Math.random(),0.25+Math.random(),-3);
document.EField.setShowFieldLines(1);
}
</script>