Which of the following instrument is most accurately for comparing electromotive force (e.m.f) of two cells?

A. Voltmeter
B. Meter rule
C. Galvanometer
D. Potentiometer

Correct Answer:

Option D – Potentiometer

Explanation

Voltmeter: An instrument for measuring electric potential in volts

Galvanometer: it is a device used to indicate the 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