Electrostatic Potential
The electrostatic potential at any point defined as the work done in bringing a unit positive charge from infinity to that point. The S.I. unit of electrostatic potential isvolt. It is denoted by symbol V.
Potential Difference
The potential difference between two points A and B in an electric field may be defined as the amount of work done in moving a unit positive charge from point A to point B.
Potential Difference = 
or
V = 
The S.I. unit of potential difference is Volt. Potential difference is a scalar quantity. The potential difference is measured with the help of an instrument called Voltmeter. It should be noted that in order to measure the potential difference of a conductor the voltmeter is connected in parallel circuit with the two ends of the conductor as shown in figure.
1 Volt
The potential difference between two points in an electric field is said to be 1 volt if 1 Joule of work is done in bringing 1 coulomb of positive charge from one point to another.
1 Volt = 
Test Your Understanding and Answer These Questions:
- What is electrostatic potential?
- What is potential difference?
- Define 1 volt?
- Name the instrument by which potential difference is measured.