History of electromagnetic theory used to create positively charged anodes and negatively charged cathodes. When a conductor was attached between these, the difference in the electrical potential (also known as voltage) drove a current between them through the conductor. The potential difference between two points is measured in units of volts in recognition of Volta's work. The first mention of voltaic electricity, although not recognized as such at the time, was probably made by Johann Georg Sulzer in 1767, who, upon placing a small disc of zinc under his tongue and a small disc of copper over it, observed a peculiar taste when the
Ampere balance from 1 to 100 centi-amperes, the deci-ampere balance from 1 to 100 deci-amperes, the ampere balance from 1 to 100 amperes, etc. Ampere balance The ampere balance (also current balance or Kelvin balance) is an electromechanical apparatus used for the precise measurement of the SI unit of electric current, the ampere. It was invented by William Thomson, 1st Baron Kelvin. The current to be measured is passed in series through two coils of wire, one of which is attached to one arm of a sensitive balance. The magnetic force between the two coils is measured by the amount of weight