Question

We know emf of a cell

• A. depends on the resistance of the circuit
• B. exists even when circuit is not used
• C. is equal to the $P.D.$ between any two points of a conductor
• D. exists throughout the circuit

Answer 1

The correct option is B

exists even when circuit is not used

The explanation for correct answer

Option B

1. Emf is the electromotive force in the circuit.
2. It is the voltage that remains if no current is flowing through the circuit.
3. Therefore it exists when circuit is not used.

The explanation for incorrect answers

Option A

1. Emf is independent of the resistance of the circuits.

Option C

1. The potential difference is proportional to the circuit's resistance and hence differs from emf.

Option D

1. Emf exists in cell or battery not across the circuit.

Hence, option (B) is the correct answer.