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.

Answer 1

Answer: (B)

Decreasing $R$ increases current in $XY$ and there by increases the potential drop across $XP$ and the balance point may be obtained. The current may be increased also by increasing $V$.