Discussion Forum



1)

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 deflections always in one direction, but the deflection decreases continuously until Y is reached. The balance point between X and Y  may be obtained by

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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:

Option B

Explanation:

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