The electric potential V at any point in an electric field is the potential energy that each coulomb of positive charge would have if placed at that point in the field.
The unit for electric potential is the joule per coulomb (J C ‑1 ), or the volt (V).
Like gravitational potential it is a scalar quantity.
In order to move a charge from point A to point B, a force must be applied to the charge equal to qE
(F = qE).
Since the force is applied through a distance x, then work has to be done to move the charge, and there is an electric potential difference between the two points.
Remember that the work done is equivalent to the energy gained or lost in moving the charge through the electric field.
At first, scientists thought that a current was made up of positive charges moving from positive to negative.
We now know that electrons really flow the opposite way, but unfortunately the convention has stuck.
Diagrams usually show the direction of `conventional current' going from positive to negative, but you must remember that the electrons are really flowing the opposite way.
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