Volt

The Volt is the unit of measurement in the International System of Units (SI) is used for the electrical potential. It was named in 1897 after the Italian physicist Alessandro Volta. As symbols of the capital letter "V" will be used.

The Volt is a coherent SI derived unit, which means it is connected to the base unit via the numerical factor of one.

Definition

Current definition in SI units

One of the pillars of the SI system of units is the equation of energy units, joules ( J), watt second (Ws) and Newton -meters (Nm )

Moreover, since the SI unit Watt ( W) is defined by

You can go to resolve

Reproducible reference

Since the above definition can be used in practice only with difficulty as a precision reference, since 1990, a voltage by means of the Josephson effect, and the Josephson constant, the reciprocal of the magnetic flux quantum determined. This constant is:

Thus can be returned to the reference measurements, the setting of a voltage to a very accurate frequency measurement ( time measurement).

Historical definition

Previously, the definition of a volt of the Weston standard cell was derived. This element provides at a temperature of 20 ° C. An electric voltage of precisely

Decimal multiples and divisions of the Volts

The Volt is in the order that covers quite voltage values ​​of everyday experience with manageable number values. With the wide range of emerging and measurable stresses the Volt is also combined with the usual attachments for units of measurement used to microvolts ( uV ) about millivolts ( mV), kilovolts ( kV ) to megavolt ( MV) for their disclosure.