It opens the circuit. It creates the electric field. It controls the amount of current. It provides energy to the circuit.
I gave my students this multiple choice question: Which of the following best describes the function of a resistor in an electrical circuit?

Only one answer is correct among these 4 choices:
- It opens the circuit.
- It creates the electric field.
- It controls the amount of current.
- It provides energy to the circuit.

Could you tell me which one is correct?

It controls the amount of current.