Define the potential difference between two points.
3. Or the potential difference between points A and B, is defined as the shift in the potential energy of a charge q, divided by the charge, shifted from A to B.
4. The SI unit of electrostatic potential difference is volt.
5. Potential difference is said to be one volt if one joule of work is done in moving a charge of one coulomb from one point to another in an electric field.
6. If a positive charge is moved from a point at a higher potential to a point at a lower potential, energy is liberated.