An electric circuit can have no current when a switch is

An electric circuit can have no current when a switch is open. that is the correct answer.

Answer;

Open

An electric circuit can have no current when a switch is open.

Explanation;An electric circuit is a path in which electrons from a voltage or current source flow. Electric switches are used to connect and break the flow of connectivity or flow of electrons in a circuit. A switch makes it easy to open or close an electrical circuit, turning the flow of electricity on or off.When a switch is closed the circuit is closed and thus the flow of current is on while when the switch is open, the circuit is open, and therefore there will be no flow of current in the circuit.

The answer would be

It will appear as o2(g) as a reactant