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Re: TC Electrosattics Revisited II


From: 	John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
Sent: 	Monday, September 15, 1997 3:02 PM
To: 	Tesla List
Subject: 	Re: TC Electrosattics Revisited II

At 03:40 AM 9/12/97 +0000, you wrote:
>
>From: 	John Berry[SMTP:antigrav-at-ihug.co.nz]
>Sent: 	Thursday, September 11, 1997 7:12 PM
>To: 	Tesla List
>Subject: 	Re: TC Electrosattics Revisited II
>
>Does this help?
>
>>From : Essentials of electromagnetism
>
-------------------------------------------------  snip

> By international agreement:
>
>"A constant current of one ampere maintained in two parallel, infinitely long,
>straight conductors of negligible cross-section separated by one metre in
>vacuum, produces a force between these conductors of 2 x lO-7 newtons per metre
>of length."
>
> After fixing the value of km in this way, it is usual in SI units to express
>(1.2) as
>
>If anyone wants to hear the rest please reply.

-------------------------------------------------------------------

   John B and All -

   The problem with the SI units system is that there is no complete
agreement between nations for some of the units. For example, Canada and
England do not agree on the units of pressure in spite of the fact they both
accept the SI system. The Conference on Weights and Measures meets every six
years and argues over terminology, units, measurements, etc. Each nation has
its own political, economic, and social reasons for wanting certain standards.

  Comparing the electrical force due to charges and the force due to
currents is not easy. The charge forces can be measured using the Coulomb
Law equation
 F = q1q2/r^2 .  The force is in dynes (CGS), the charges in statcoulombs
(q), and the (r) in centimeters. One coulomb = 10^9 statcoulombs.  

 The current forces can be measured by the equation   
F = BLI .  The force is in newtons (MKS), the currents (I) in amperes, the
wire length (L) in meters, and the magnetic field  (B) in webers per sq
meters.  This gives the
 2 x 10^-7 newtons per meter.

   Note that these two methods of measuring electrical forces require an
agreement as to the relationship between the units of the CGS and MKS
systems (SI).

   As far as Tesla coils are concerned the knowledge of how unit
measurements and standards are determined are of little value. However,
understanding how to properly test and evaluate a Tesla coil is of paramont
importance. There should be more discussion on testing Tesla coils because
many postings of results indicate that coilers need more information on
testing methods and evaluations.

   John Couture