Thread: Eric Dollard
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Old 07-24-2012, 05:03 AM
garrettm4 garrettm4 is offline
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Law of Electromagnetic Induction, from Steinmetz T&C of AC Phenomena

No explanation is provided as to the reason for the reversal of the power of ten, from plus eight, to minus eight. We are off to a good start here!
I may be wrong on this, but I believe Steinmetz prefers the use of the maxwell instead of the weber for the unit of magnetic flux, at least for introductory explanations. This is why the use of 10^8 and 10^-8 make their appearance in his engineering expressions. Whereby 1 maxwell is a single loop of magnetic flux and one hundred million, 100,000,000 or 10^8 maxwells cutting a single turn conductor per second is one volt of E.M.F.

It is that one weber cutting a single turn conductor per second is also one volt of E.M.F. This relates the two by the factor of 10^8 or one hundred million maxwells is equivalent to one weber. Thus Steinmetz's expressions are confounded by 10^8 and 10^-8 due to the choice of unit for the measurement of magnetic flux. This is probably obvious to most, but I thought I would help clarify for those who are new or unfamiliar with this subject.

Concluding, Steinmetz starts off with the explanation in maxwells or "lines" but then converts this into webers by the use of 10^-8. I believe this is done to develop the significance of a single loop of magnetic flux, or one maxwell, while at the same time keeping the discusion relevant by making the expressions equivalent to units in webers. However, this portrayal may seem like a nuance to some, due to the added mathematical baggage needed to keep everything in order.

A helpful companion reference for this topic is The Magnetic Circuit 1911 by Vladimir Karapetoff. Given below are pages 6-7 of Karapetoff's book, which covers the differences between the maxwell and the weber:

Also, I thought I would put up the referenced pages of Steinmetz's book, Theory and Calculation of Alternating Current Phenomena, for quick perusal by those interested in the T-Rex Transmissions:

Garrett M

Last edited by garrettm4; 08-06-2012 at 05:32 PM.
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