Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!rutgers!ll-xn!cullvax!drw
From: drw@cullvax.UUCP (Dale Worley)
Newsgroups: sci.electronics,sci.physics
Subject: resistance of earth ground
Message-ID: <1315@cullvax.UUCP>
Date: Thu, 25-Jun-87 10:38:20 EDT
Article-I.D.: cullvax.1315
Posted: Thu Jun 25 10:38:20 1987
Date-Received: Sat, 27-Jun-87 01:24:15 EDT
Organization: Cullinet Software, Westwood, MA, USA
Lines: 24
Xref: mnetor sci.electronics:855 sci.physics:1769

wolfgang@haddock.UUCP (Wolfgang Rupprecht) writes:
> 	What is the resistance of earth ground? Let's say we have two
> good connections to the earth, say two Chevettes :-), dropped into the
> ocean, one into the Pacific and the other Atlantic. With an ohm-meter
> connected between them, what kind of resistance can I expect to see?

One thing you run into is that with a point contact to a 3D medium,
resistance of the contact is dominated by what happens near the
contact:  Consider a spherical shell A of finite thickness around the
contact, and another B with double the radius and thickness.  The
contribution of A to the contact resistance is twice that of B.  If
the contact is a perfect point, the contact resistance is infinite!

Getting back to the example, the Chevettes make pretty good contact
with a lot of ocean, so the resistance would probably be damn close to
zero.

Dale


-- 
Dale Worley	Cullinet Software		ARPA: cullvax!drw@eddie.mit.edu
UUCP: ...!seismo!harvard!mit-eddie!cullvax!drw
************** REPLACE THIS LINE WITH ONE EXACTLY LIKE IT **************