Question

A potentiometer circuit shown in the figure is set up to measure emf of cell E. As the point P moves from X to Y, the galvanometer G shows deflection always in one direction, but the deflection decreases continuously until Y is reached. The balance point between X and Y may be obtained by

• A. decreasing the resistance \( R \) and decreasing \( V \)
• B. decreasing the resistance \( R \) and increasing \( V \)
• C. increasing the resistance \( R \) and increasing \( V \)
• D. increasing the resistance \( R \) and decreasing \( V \)

Hint:

To achieve the balance point in a potentiometer, the resistance \( R \) and voltage \( V \) are adjusted to match the potential difference of the cell being measured.

Answer 1

The Correct Option is A

Step 1: Working of Potentiometer.
The potentiometer works by balancing the potential difference from the cell under measurement with the potential from a known reference source. Adjusting the resistance \( R \) and voltage \( V \) allows for the balance point to be achieved.
Step 2: Conclusion.
The correct answer is (A), decreasing the resistance \( R \) and decreasing \( V \).