Voltage

Voltage is a quantity (= Größe) in physics that describes how powerful the force on the electrons is. Voltage is always measured between two points IN THE ELECTRIC FIELD. Voltage tells us how big the difference between the potential energy of an electron between those two points is. One can calculate how much energy of the electron between the two points is transformed from potential energy to kinetic energy and back again.

The symbol for voltage is U. The origin of this symbol is the Latin word „urgere“, which can be translated into English and means more or less to push or to force.
The unit of voltage is volt. The unit volt, like ampere, direves from the surname of a physicist. The Italien Alessandro Volta lived from 1745 to 1827.
Voltage always drops at an element of a circuit. One can only measure it if the measuring instrument is added parallelly to that element.
If you know the amperage and the resistance, you can calculate the voltage by using this formula:

Here are some examples of voltage values in our everyday life:

Rechargeable batteries	1,2 volts
Car batteries	12 volts
Supply voltage in Europe	230 volts
Trams	550 volts
Electric locomotives	up to 15.000 volts
High voltage lines	up to 38.000 volts