Re: toroid inner

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:
 >
 > Original poster: Bart Anderson <classi6-at-classictesla-dot-com>

 > Also interesting, where the minor diameter is very small (1" x 15"),
 >
 > 285.31 kHz (11.166 pF) w/o disc
 > 279.8 kHz (12.464 pF) with disc
 >
 > Greater change, but still, in the scheme of things it doesn't really affect
 > much (unless your comparing error of a program to a measurement, etc.).

Trying to find what would be the dimensions of a toroid where closing
the hole with a thin disk doubles the capacitance (in free space):
I will use 1 meter as radius of the center of the "tube" and change
the radius of the tube "r"

r (m)    toroid     w/disk
0.1      80.299     84.669
0.01     52.298     72.247
0.001    38.894     70.987

It's evident that the capacitance of the combination is tending to the
capacitance of a 2 meters thin disk: 70.834 pF

0.0004   35.296     70.898

This is a toroid with 2 meters of diameter and 0.8 mm of thickness!

Antonio Carlos M. de Queiroz