Q. Potentiometer measures the potential difference more accurately than a 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
Explanation
(c) 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.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.