Xref: utzoo sci.electronics:8000 sci.physics:9843
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!amdahl!amdcad!diablo!phil
From: phil@diablo.amd.com (Phil Ngai)
Newsgroups: sci.electronics,sci.physics
Subject: Re: A violation of the law of conservation of energy
Keywords: paradox
Message-ID: <27549@amdcad.AMD.COM>
Date: 29 Sep 89 02:11:58 GMT
References: <318@massey.ac.nz>
Sender: news@amdcad.AMD.COM
Reply-To: phil@diablo.AMD.COM (Phil Ngai)
Organization: Advanced Micro Devices, Inc. Sunnyvale CA
Lines: 18

In article <318@massey.ac.nz> ARaman@massey.ac.nz (A.V. Raman) writes:
|By definition then, the energy transferred from V to C is
|charge * pressure = 1V * 1C = 1 joule
|But what is the energy stored in the capacitor?
|It is half C*square(V) = half * 1 * square(1) = half joule.
|Where has the remaining half joule gone?
|Beats me!

Congratulations, you've come up with an example which shows that the
circuit model of reality has idealizations which can lead to incorrect
answers. Any model of reality will have corners where they are not
useful. Part of your job as an engineer is to know when you are
getting close to one of those corners and what to do about it. In
this case, you have to go to a lower level and use an E&M model.

--
Phil Ngai, phil@diablo.amd.com		{uunet,decwrl,ucbvax}!amdcad!phil
"Should the US send assault rifles to Colombia? How about small arms?"