Measuring Devices ( Galvanometer, Voltmeter and Ammeter & Meter Bridge ): Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Measuring Devices ( Galvanometer, Voltmeter and Ammeter & Meter Bridge ). Understanding the underlying formula is key to arriving at the correct answer below:

At the balancing point, no current is drawn from the secondary circuit by the potentiometer.
Thus, it acts as an ideal voltmeter with infinite resistance.
It measures potential difference across open circuit conditions without disturbing the circuit.