>-----Original Message-----
>From: Rick Regan [mailto:drrdr@CHARTER.NET]
>Sent: 16 April 2004 13:42
>To: PICLIST@MITVMA.MIT.EDU
>Subject: Re: [EE]: Why isn't Ohm's Law written I=V/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.
>
>Noone said that any of the arrangements were invalid.  I
>was looking for the more "natural" way to express it
>because I assumed only V and R could be manipulated
>directly.  However, several have pointed out that I
>(current) can also be manipulated directly, which I did
>not know.  (I still don't understand how but that's ok
>for now I guess).

You can only change current by changing voltage or resiatnce, as per Ohms
law!  A bench supply in constant current mode simply adjusts voltage to
achieve the desired current through an arbitrary resistance

>
>In any case, I still think I=V/R is more intuitive for
>the beginner. Different batteries and resistor values can
>be plugged in to cause a change in I.  At least it helps
>my view of the world....

It's only usefulll in that form when you need to derive current from a known
voltage and resistance. Without wishing to be rude, the fact that you don't
understand how a constant current supply can be realised means that you may
not have fully grasped the funadmentals regarding Ohms law.  I would guess
that you find I=V/R intuitive simply because it happens to be the form in
which you most commonly use the law?

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