The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: Michael J. Schülke
Subject: Re: Complex number quiz
Date: Tue, 10 Sep 2002 14:04:20 +0200
References: <3D7DBD37.27C9BDEC@ipricot.com> <firstname.lastname@example.org>
X-Newsreader: MicroPlanet Gravity v2.50
> A string of resistors infinitely long thus:-
> 5R | 5R |
> \ \
> / 9R / 9R etc etc etc
> \ \
> / /
> 8R | 8R |
> The right hand side of the chain continues out of the window. What is the
> resistance measured on the left hand side ?
> You can't actually measure it because the electrons would take an infinitely
> long time to travel the circuit so you'll have to calculate it.
> Any takers ?
Let Z be the resistance of the chain. Since the chain is infinite,
taking away or adding one element at the front shouldn't make a
1 9R * Z
Z = 5R + ---------- + 8R = 13R + ------
1/9R + 1/Z 9R + Z
(Z - 13R) (Z + 9R) = 9R * Z
Z^2 - 13R * Z - 117 R^2 = 0
Z = 19.1 R
From-address is valid, but used as spam trap. Write to MJSchuelke at gmx
dot net for a faster reply.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup