Question

which one of the following is the appropriate option for fill in the blank: conductor, switch, resistance? all electric circuits have at least two parts: a voltage source and a

Explanation:

An electric circuit must have a voltage source to provide electrical energy and a resistance (which can be in the form of a component like a light - bulb, heater etc., that opposes the flow of electric current). A conductor is just a material that allows current to flow (like wires which are also part of the circuit but not one of the two'main' essential parts in the basic definition). A switch is used to open or close the circuit (it is not an essential part for the circuit to be considered as a circuit in the most basic sense, as a circuit can exist without a switch, just with a source and a load (resistance)).

Answer:

resistance