The emf of a cell is the ratio of the difference in

Options

A. charge in coulombs to the electrical potential energy in joules
B. electrical potential energy in joules to the charge in coulombs
C. electrical potential energy in joules to the resistance
D. electrical potential energy in joules to the time

Answer

B

Explanation

The fact that electrons flow from one elctrode to the other indicates that there is a potential (or voltage) difference between the two electrodes. This potential difference between the electrodes, called the electromotive froce, or `emf(E)`, is most conveniently described as potential, which is the potential energy per unit charge. We measure this quantity in volts. The volt `(V)` is the `SI` unit of potential difference.
The electrical work expended in moving a charge through a conductor is
Electrical work = charge `xx` potential difference
Corresponding `SI` units for the terms in the terms in this equationare
Joules = coulombs `xx` volts