Question

In a potentiometer of ten wires, the balance point is obtained on the sixth wire. To shift the balance point to eighth wire, we should

• A. increase resistance in the primary circuit.
• B. decrease resistance in the primary circuit.
• C. decrease resistance in series with the cell whose e.m.f. has to be measured.
• D. increase resistance in series with the cell whose e.m.f. has to be measure.

Answer 1

The correct option is A increase resistance in the primary circuit.

By increasing resistance in the primary circuit the P.G of the wire decreases thereby it requires more length to measure the emf of secondary cell.
$\therefore$ By increasing the resistance in series circuit we can move balancing point from sixth to eight wire.