Question: In a potentiometer experiment, if the balance point is found at 4 m with a 6 V battery, what is the voltage across a 2 m length of the wire?

Options:

1. 2 V
2. 3 V
3. 4 V
4. 1 V

Correct Answer: 3 V

Solution:

The potential gradient is 6 V / 4 m = 1.5 V/m. Therefore, across 2 m, the voltage is 1.5 V/m * 2 m = 3 V.