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From: jroersma@orion.oac.uci.edu (John Roersma)
Newsgroups: sci.electronics
Subject: Electric Fences (why does person on end get the shock?)
Keywords: electric shock
Message-ID: <3858@orion.cf.uci.edu>
Date: 27 Dec 89 22:52:41 GMT
Reply-To: jroersma@orion.oac.uci.edu (John Roersma)
Distribution: na
Organization: University of California, Irvine
Lines: 29



Please help settle an argument regarding shocks from electric fences.
My parents both grew on farms with electric fences which would give
a strong shock when touched.  They have told me that they had
experiences where some kids would grab another person (or persons)
and touch the fence, and that the person at the end of this human chain
would get the (worst) shock (!).

Why does the person on the end of the chain (the person farthest
from the fence) get the shock, assuming each person has roughly
the same arm-to-arm and arm-to-ground resistance.  Modeling this
as a resistive network shows that the person in contact with
the fence will experience the largest arm-to-ground voltage drop
(hence the largest current and largest shock).

I have tried to state my case to my parents, although they have
had the opportunity to experience the shock at both ends of the
"chain", and will swear that the shock _is_ worse at the far end!

Who's correct here?  Have I made an oversight, or is there some other
physical phenomenon involved?


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John Roersma                                 jroersma@orion.oac.uci.edu
Dept.of Electrical & Computer Enginering        jroersma@ucivmsa.bitnet
University of California, Irvine    >> this space available for rent <<
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