Question
A potentiometer can measure emf of a cell because:
✓
Answer
- No current flows in the wire of potentiometer at balance.
Potentiometer is preferred over voltmeter because it measures true emf of the cell. It uses null method so that no current is drawn from cell in balanced condition, as E - Ir = V and I = 0 then V = E.
Hence emf measurement is more accurate.
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