What defines a complete electric circuit?

A complete electric circuit is fundamentally characterized by a continuous loop that allows electrical current to flow without interruption. This is captured by the concept that for current to operate effectively, it must have a path that connects all components together in a closed loop.

The idea of a flow of current returning to the generating source is crucial; if the current cannot complete its journey back to the source, the circuit is open and cannot function as intended. In a properly functioning circuit, the current travels from the power source, flows through various components such as resistors or bulbs, and eventually returns to the power source, allowing for the completion of the circuit.

The other choices, while they touch on aspects of electric circuits, do not encapsulate the essence of what defines a complete circuit as accurately. For example, having a path from the source through the resistors describes part of the circuit but does not address the necessity of closure. The connection from positive to negative current highlights current flow direction but again, lacks the completeness criterion that is vital for circuit operation. Lastly, while a loop of current without interruption is related, specifying the return to the generating source emphasizes that the source is integral for sustaining current flow, reinforcing the definition of a complete electric circuit.