# What is volt?

Volt is the name given to a derived unit that is part of the International System and that serves to express the electric potential, the electric voltage and the electromotive force. The word volt comes from Volta, the surname of the physicist who invented the electric battery: Alessandro Volta (1745 – 1827).

A volt is equal to the potential difference between two points on a given conductor when, in order to carry a charge of one coulomb from one point to another, it is necessary to do the work of one joule.

As can be seen in the definition mentioned above, it is necessary to know several concepts to understand what a volt is. Electric potential is the work that requires an electrostatic field to carry a positive charge between two points. A coulomb is a unit of measurement linked to the amount of electrical charge that a given current carries in one second. The joule is a unit that refers to the work required to carry an electrical charge of one coulomb. It should be taken into account that when two points with a potential difference are connected through a conductor, a flow of electrons is generated. This process of moving charges is what we know as electric current. Volts allow you to quantify this difference in potential or electrical voltage that is produced. Electricity homes, in most South American countries, have a value of 220 volts (or 220 V, since V is the volts symbol), while in North America it is 120 V. Cars generally use 12V electricity. It should be noted that the number of volts can be termed as voltage. On the other hand, we find the standard volt , which we can define as the voltage needed to generate, in a Josephson oscillator , a frequency of 483 597.9 GHz . This oscillator has a more stable oscillation frequency than normal, and is defined in the formula f = 2eΔV / h , where e represents the electron charge and h is Planck’s constant. This last concept, also known as the Josephson effect, arises when an electric current occurs between two separate superconductors through the tunneling effect, that is, when the particles penetrate an impedance or potential barrier that exceeds their own kinetic energy.