Define the SI Unit of Potential Difference. 

The S.I. Unit of potential difference is volt (V). It is named after Alessandro Volta who invented the battery.

As, potential difference is defined as the work done in moving one coulomb of charge from one point to the other.

Thus, potential difference between two points is said to be 1 volt if work done in transferring 1 coulomb of charge from one point to the other point is 1 joule.