[SI-LIST] Continue on the topic of partial inductance.

Continue on the topic of partial inductance.
 
I was trying to explain the equation of circular wire loop inductance. 
L= 1.56e-8*D*(ln(8D/r)-2) ; (refer to Dr. Johnson's black magic) 
D: circle diameter
r: wire diameter
 
Let's assume the loop is as large as the earth, so that each segment will look 
like flat. Mutual inductance will be ignorable due to the large distance 
between local segment and other ones. Thus, partial inductance should be 
derived from:
Loop Inductance divide by perimeter = 1.56e-8*D*(ln(8D/r)-2)/(6.28*D) = 
0.02nH*(ln(8D/r)-2)
 
It made me surprised that "partial self inductance" still approach infinity, 
which is not true according to the math calculation by Grover's formula. 
 
Which assumption was broken by above derivation? I guess the reason is the loop 
inductance equation no longer stands when D becomes very large.
 
thanks,
Han
                
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