Question

For measurement of potential difference, potentiometer is perferred in comparison to voltmeter because
A. It has a wire of high resistance
B. It has a wire of low resistance
C. It does not draw current from external circuit
D. It draws a heavy current from external circuit

Answer 1

Correct Answer - C
When we measure the emf of a cell by the potentiometer then no current draws in the circuit in zero -deflection condition i.e., 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.