Question
Potentiometer measures the potential difference more accurately than a voltmeter because:
✓
Answer
- it does not draw current from external circuit.
When we measure the emf of a cell by the potentiometer then no current flows in the circuit in zero-deflection condition ie, cell is in open circuit. Thus, in this condition the actual value of a cell is found. In this way, potentiometer is equivalent to an ideal voltmeter of infinite resistance.
Note. The emf in the potentiometer is measured by null method in which zero deflection position is found on the wire.
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