What defines an open circuit?

An open circuit is defined by a condition where the flow of electricity is interrupted, meaning that there is a break in the path through which current can travel. This typically occurs when a switch is open. In such a scenario, the circuit is incomplete, preventing current from flowing.

The other options relate to different aspects of electrical circuits but do not define an open circuit specifically. For instance, a closed switch creates a complete circuit, allowing current to flow freely. Bare wires are a safety concern rather than a defining characteristic of an open circuit. Lastly, while voltage may still be present in an open circuit due to potential difference, it doesn't imply that current is flowing, which is essential for defining an open circuit. Thus, defining the open circuit based on a switch being open is accurate, as it captures the essence of the circuit being incomplete.