Simple Circuit A simple circuit consists of three minimum elements that are required to complete a functioning electric circuit: a source of electricity (battery), a path or conductor on which electricity flows (wire) and an electrical resistor (lamp) which is any device that requires electricity to operate. The illustration below shows a simple circuit containing, one battery, two wires, a switch, and a bulb. The flow of electricity is from the high potential(+) terminal of the battery through the bulb (lighting it up), and back to the negative (-)terminal, in a continual flow when the switch is in the on position so current can flow.