>-----Original Message----- >From: Rick Regan [mailto:drrdr@CHARTER.NET] >Sent: 15 April 2004 19:46 >To: PICLIST@MITVMA.MIT.EDU >Subject: Re: [EE]: Why isn't Ohm's Law written I=V/R? > > >> But I is only the dependant variable in *one* way of >> looking at it. V=IR is the appropriate way of writing it >> if you consider ohm's law to mean " V = the voltage drop across >> resistance R with current I passing through it". You can >come up with >> a similar, equally valid phrase, for the third way of writing it out >> (r=v/i). > >But aren't R and V the only two of the three variables >that you can manipulate directly? I depends on these, >right? I think writing it I=V/R would be less confusing >to the novice. With the V=IR form, I've seen >descriptions like "if the current doubles the voltage >doubles." Mathematically, yes, but it's not like you can >double the current independently of V and R. > So how does this apply to any other arrangement? It's not like you can vary ANY ONE of the parameters without affecting the others. i.e. varying voltage across a fixed resistance changes the current, changing the current through a fixed resistance varies the voltage across the resistance. It's basic maths, given one fixed parameter the Ohms law states the other two are either proportional or inversely proportional to each other. You can hardly single out one arrangement of the formulae and say it's not valid. Regards Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. ======================================================================= Any questions about Bookham's E-Mail service should be directed to postmaster@bookham.com. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads