Each and every material in this world is made up of atoms. Each atom is build up of protons, which are positively charged, electrons, which are negatively charged and neutrons which are neutrally charged. As we know a force of attraction prevails between these positively charged protons and negatively charged neutrons.

## Potential difference

Whenever we want to separate two oppositely (positive and negative) charged particles that have strong binding forces between them holding them together, we need to do some certain amount of work in separating them by overcoming the force of attraction between them. The work done in separating them apart is stored as potential energy in each of these charged particles. The difference in potential energies of these particles is called as potential difference.

## What is voltage?

Once you have understood the above said points, it is easy to understand what voltage is?

“Voltage is simply the electrical term used for this potential difference. In other words, the potential difference in Electrical engineering is termed as voltage.”

## Mathematical representation of Voltage

As said above voltage is the difference in potential between two points. It is denoted by the alphabet V. The unit of voltage is “volts”.

Voltage V= ^{W}/_{Q } or v= ^{dw}/_{dq}

Where,

W – Work done in moving those charges.

Q- Coulombs of charge.

## One volt

One volt can be defined as the potential difference between two points when one joule of energy is used to pass one coulomb of charge from one point to the other.

## Example problem on voltage:

30 joules of energy is consumed in separating two charges of 10 coulombs each over a distance. What will be the voltage developed?

**Solution:**

Voltage V= ^{W}/_{Q } = 30/10 = 3V