Question

What is the significance of the null deflection condition in a Wheatstone bridge?

Options

• It indicates that the total current from the battery is maximum

• It indicates that the voltage across the battery is zero

• It indicates that all resistances in the bridge are equal

• It indicates that the potentials at the two galvanometer junctions are equal, and no current flows through the galvanometer

Answer 1

Null deflection occurs when the galvanometer shows zero deflection, meaning no current flows through it (\[I_g = 0\]). At this stage, the potentials at the two galvanometer junctions become equal, allowing the balance condition to be applied for accurate resistance measurement.