A complete electrical circuit requires a power supply, a switch, and a load. As its name suggests, the power supply provides power (in this case, it’s a battery). A switch opens or closes the circuit by making or breaking the electrical pathway and passing power (in this case, it’s a double-pole double-throw switch). A load is an object that converts electromotive force by resisting electrical flow; it’s the part that does what we want it to accomplish (in this case, it’s a motor).

The circuit creates a circle, and we can do that by wiring components into and out of each other; the power supply connects to the switch in one direction and the load in the other direction, and the switch also connects to the load. Electrons are stored on the negative side of a battery, so they move from the negative side of the battery through the circuit.

Our path starts off incomplete. However, when we close the switch, we complete the path and see that the motor starts spinning.