Changes

==== Watt ====

==== Watt ====

The '''watt''' (symbol W, named for [[James Watt]]) is the [[power]] required to do one Joule of work in one second. To calculate, divide work by time.

The '''[[watt]]''' (symbol W, named for [[James Watt]]) is the [[power]] required to do one Joule of work in one second. To calculate, divide work by time.

=== Electricity and Magnetism ===

=== Electricity and Magnetism ===

==== Coulomb ====

==== Coulomb ====

The '''coulomb''' (symbol C, for [[C. A. Coulomb]]) is that amount of [[electric charge]] that passes through a conductor in one second at a current of one ampere. To calculate, multiply current by time.

The '''coulomb''' (symbol C, for [[C. A. Coulomb]]) is that amount of [[electric charge]] that passes through a conductor in one second at a current of one ampere. To calculate, multiply current by time.

==== Volt ====

==== Volt ====

The '''volt''' (symbol V, named after Alessandro Volta) is the [[electric potential]] difference between two conductors having a current flow of one ampere from one to another, and dissipating one watt of power. Most people find the phrase "electric potential" hard to understand and the alternative "electromotive force" to be hard to pronounce. They therefore use the word "voltage" for this quantity. To calculate, divide power by current--or divide work (or energy) by electric charge.

The '''[[volt]]''' (symbol V, named after Alessandro Volta) is the [[electric potential]] difference between two conductors having a current flow of one ampere from one to another, and dissipating one watt of power. Most people find the phrase "electric potential" hard to understand and the alternative "electromotive force" to be hard to pronounce. They therefore use the word "voltage" for this quantity. To calculate, divide power by current--or divide work (or energy) by electric charge.

==== Ohm ====

==== Ohm ====

The '''ohm''' (symbol Ω, for [[Georg Simon Ohm]]) is that amount of [[electric resistance]] that requires an electric potential difference of one volt to push a current of one ampere through it. To calculate, divide electrical potential by current.

The '''[[ohm]]''' (symbol Ω, for [[Georg Simon Ohm]]) is that amount of [[electric resistance]] that requires an electric potential difference of one volt to push a current of one ampere through it. To calculate, divide electrical potential by current.

==== Siemens ====

==== Siemens ====

The '''siemens''' (symbol S, for [[Werner von Siemens]]) is the unit of [[electric conductance]], which is merely the reciprocal of resistance. In essence, the siemens is that level of conductance required to ''allow'' a current of one ampere to flow through a load after an electric potential of one volt is applied. To calculate it, divide current by electric potential or "voltage," rather than dividing voltage by current.

The '''siemens''' (symbol S, for [[Werner von Siemens]]) is the unit of [[electric conductance]], which is merely the reciprocal of resistance. In essence, the siemens is that level of conductance required to ''allow'' a current of one ampere to flow through a load after an electric potential of one volt is applied. To calculate it, divide current by electric potential or "voltage," rather than dividing voltage by current.