Which of the following describes a closed conducting loop through which an electrical current can flow?
-resistance
-circuit
-voltage
-electrical pressure

I think the correct answer is the second option. A circuit describes a closed conducting loop through which an electrical current can flow. It is a path that an electrical current could flow. A circuit could be a closed one or an open circuit. A closed circuit would be a circuit where the current could flow continuously. An open circuit would be a type of circuit where the flow current would only go once and stopped at a particular point since the current has nowhere to go. For a circuit to work, an electric supply should be available to supply the electric current.

The sunlight shines uv radiation on earth,a microwave oven radiates waves on food