https://mail.google.com/mail/?ui=2&...&th=13350dc1754a8105&attid=0.0&disp=inline&zw Can someone explain why the source must also be hooked up to ground. I know it completes the circuit but whats the point? Why wouldn't current flow without it? Since the line is at a positive potential then there is a resistor(acting as a house) then house is connected to ground. Seems as if current should flow from high to low potential. Having a dumb day can't figure stuff out.