Voltage is also known as potential difference, electric pressure, and electric tension. But in regular conversation, the voltage term is more popular. Electric pressure and electric tension are the old names of Potential difference. In this time also, the term tension is used as voltage in power system i.e. high-tension transmission line (HT line) for high-voltage transmission line.

Voltage is defined as the potential difference between two points of conductor or resistor. It is also defined as the work needed per unit charge to move between two points.

When electrons are supplied to the body of electrons removed from the body, some work needed to do. This work is stored in the form of electric potential in the body. This energy is released in the form of the force of attraction or repulsion when it comes in contact with other charged bodies.

## Unit of Voltage

The SI unit of voltage is volt (V). The unit of work per unit charge is joule per coulomb. The electrical potential is defined as work done per unit charge. Hence, the equation is;

The work done is measured in joules and the charge is measured in coulomb. Therefore, the unit of voltage is joule/coulomb.

1 volt is defined as the energy required of one joule per electric charge of one coulomb. It means that the value of work done and a charge is one.

## Definition of the Potential of an Electric Field

The potential difference is defined as the amount of work done to carry a unit charge from one-point A to another point B in the electric field.

In this condition, the work done to move charge from A to B without causing any acceleration is equal to the voltage increase from point A to B.

This term mathematically expressed by the line integral of the electric field with a path. And it cause the flow of current.