What must be true for current to be present in electrical circuits?

For current to be present in electrical circuits, the circuit must be complete. A complete circuit allows electrons to flow from a power source, through the load, and back to the source. When a circuit is complete, there is a continuous path for the flow of electric current.

In a complete circuit, elements such as switches and connections are properly in place, which ensures that there are no gaps that would hinder the flow of electricity. This principle is fundamental in understanding how electrical systems operate; if the circuit is incomplete, either by a break or an open switch, current cannot flow.

The other aspects, such as resistance or the type of current, do not directly dictate the presence of current. While high resistance can reduce current flow according to Ohm's Law, it does not prevent current flow in a complete circuit. Similarly, while a circuit can be designed for alternating current (AC) or direct current (DC), the essential requirement for current flow remains that the circuit is complete.