Question

A potentiometer is superior to a voltmeter for measuring a potential because

• A. voltmeter has high resistance
• B. resistance of potentiometer wire is quite low
• C. potentiometer does not draw any current from the unknown source of e.m.f. to be measured
• D. sensitivity of potentiometer is higher than that of a voltmeter

Answer 1

The correct option is C potentiometer does not draw any current from the unknown source of e.m.f. to be measured

A voltmeter cannot be ideal in the practical experience.
But in potentiometer there will be no current drawn from the e.m.f that is to be measured. Hence potentiometer is superior to voltmeter.