Return-Path: Received: (qmail 9091 invoked from network); 11 Nov 2002 08:47:43 -0000 Content-Transfer-Encoding: 8bit Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 11 Nov 2002 08:47:43 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 3360 invoked from network); 11 Nov 2002 08:48:49 -0000 Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 11 Nov 2002 08:48:49 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18BAEE-0005BW-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 11 Nov 2002 08:47:30 +0000 Received: from [192.5.29.49] (helo=relay.dstl.gov.uk) by post.thorcom.com with smtp (Exim 4.10) id 18BAEE-0005BM-00 for rsgb_lf_group@blacksheep.org; Mon, 11 Nov 2002 08:47:30 +0000 Received: (qmail 15430 invoked from network); 11 Nov 2002 08:47:24 +0000 Received: from warlock.dstl.gov.uk (192.5.29.10) by relay.dera.gov.uk with SMTP; 11 Nov 2002 08:47:24 +0000 Message-ID: <7D653C9C42F5D411A27C00508BF8803DCB9CCB@mail.dstl.gov.uk> From: "Talbot Andrew" To: "LF Group \(E-mail\)" Date: Mon, 11 Nov 2002 08:46:28 -0000 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Subject: LF: A puzzle for Monday Content-Type: text/plain; charset=iso-8859-1; format=flowed X-Spam-Status: No, hits=0.3 required=5.0tests=EXCHANGE_SERVER,SPAM_PHRASE_03_05,SUBJECT_FREQversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group You have a small box whose internal workings you can't see, but the box has two terminals. You measure these two terminals with a voltmeter, and it measures precisely 1V. You short the two terminals with an ammeter, and it reads precisely 1A. You then conclude the internal circuit is either a Thevenin source (an ideal 1V voltage source with a 1-ohm series resistor) or a Norton source (an ideal 1A current source with a 1-ohm shunt resistor). Using standard laboratory equipment, how could you determine which one it is. "This e-mail is intended for the recipient only. If you are not the intended recipient you must not use, disclose, distribute, copy, print, or rely upon this e-mail. If an addressing or transmission error has misdirected this e-mail, please notify the author by replying to this e-mail." "Recipients should note that all e-mail traffic on MOD systems is subject to monitoring and auditing."