Which of the following statements about electric current are correct?
(A) The SI unit of electric current is Volt.
(B) Electric current provides the rate of flow of the electric charge.
(C) A cell or battery provides the potential difference for electric current to flow.
(D) Electric current flows from lower potential to higher potential inside a conductor.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (B) and (C) only
Electric current is the rate of flow of electric charge through a conductor, \(I=\frac{Q}{t}\). Charge flows only when there is a potential difference between the ends of the conductor, and a cell or battery maintains it.
(A) The SI unit of electric current is Volt. Incorrect. The SI unit of current is the ampere (A), one coulomb of charge per second. The volt is the unit of potential difference.
(B) Electric current provides the rate of flow of the electric charge. Correct. Current is defined as the charge passing a point per unit time, so it gives the rate of flow of charge.
(C) A cell or battery provides the potential difference for electric current to flow. Correct. The chemical action inside a cell sets up a potential difference across its terminals, which drives the charges round the circuit.
(D) Electric current flows from lower potential to higher potential inside a conductor. Incorrect. In a conductor, current flows from higher potential to lower potential, from the positive terminal through the circuit to the negative terminal. (The electrons themselves drift the other way.)