Which of the following instrument is most accurately for comparing electromotive force (e.m.f) of two cells?
Voltmeter
Meter rule
Galvanometer
Potentiometer
Correct answer is D
Voltmeter: an instrument for measuring electric potential in volts
Galvanometer: it is a device used to indicate direction of a small electric current
Potentiometer: is a device for measuring or comparing e.m.fs of cells
Meter rule: measuring a distance at different points