Question

The current which flows in a galvanometer
of Wheatstone bridge is directly
proportional to
A) the resistance of a battery.
B) the resistance of the galvanometer.
C) value of the unknown resistance.
D) ratio P/Q of ratio arms.
​

Answer 1

Answer:

Answer is C.

In the first case, the deflection in the galvanometer is the zero as there is no current flow through the galvanometer in a balanced Wheatstone bridge because, in the balanced state, the voltage on both terminals of the galvanometer is the same. Since the voltage differential in zero, there can be no current.

In the second case, the positions of the battery and galvanometer are interchanged, which makes no difference in the voltage difference as the values of resistances and battery remain the same.

Hence, the new deflection of the galvanometer will be zero.