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Re: The unit of a "Faraday"

 Hi all,
It is a Faraday when I feel competent to contribute to a Tesla list thread. 
This may cause our patient moderator to finally ax this entirely 
off-the-subject topic.

Michael Faraday did pioneering work in electrochemistry and taught us how to 
electroplate and how to use a coulometer. Following the work of Oerstead and 
Ampere, Faraday determined that a constant quantity of charge will deposit 
one gram
atomic weight (1 GAW) of a mono-valent element such as silver and gold, 1/2 
GAW of a
di-valent element such as copper or zinc.

The Coulomb is first defined by Coulomb's torsion balance as used to 
determine the electrostatic force between two charges at a set distance. As 
with the Cavendish experiment to measure the gravitational force between two 
masses, the electrostatic
force between two charges is directly proportional to the magnitude of the 
charges, and inversely proportional to the square of the distance between 
them--an inverse-square-law. In coulometry, the Ampere is a Coulomb/second 
which makes the Coulomb an Ampere*second and is measured by a silver 
coulometer as the amount of charge that
will plate out 0.001118 grams of silver in one-second. The GAW of silver is 
107 grams.
Amazingly enuff, upon dividing 107 grams/GAW by 0.001118 grams/Coulomb you 
derive the constant of 96,500 Coulombs/GAW which is the unit known as the 
Faraday.

The work of Michael Faraday in electrochemistry and electromagnetism produced 
much of the structure of 19th century physics, but it wasn't until around 
1910 that Robert Millikan earned part of his Nobel Prize with his famous 
oil-drop experiment to measure the fundamental charge on the electron: 1.6 x 
10^ -19 Coulombs. The Avogadro hypothesis
predates Millikan by 100 years; Avogadro never knew the number, but the 
bricks of modern physics now fall into place. Dividing 96,500 Coulombs/GAW by 
1.6 X 10^ -19 Coulombs/electron derives the fundamental Avogadro constant: 
6.03 x 10^ 23 electrons/
GAW.

In SI-MKS units, the Coulomb is now added to the meter-kilogram-second.

The Tesla page is the greatest.

Ralph Zekelman