an observation on Ohms Law
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

 Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
 6th May 2004, 09:07 PM #1 johnkramer   diyAudio Member   Join Date: Aug 2001 Location: somewhere in the hills of PA an observation on Ohms Law curious, at what point in time did E transpose to V? I saw E expressed as V in Ohms law recently and I thought it was a mistake. But when I googled I came across a few sites that express it like this. I learned that voltage was expressed as E E= Voltage or (E)nergy I= Current or (I)ntensity R= Resistance (obvious) P= Power (obvious) P=IE and E=IR or Pie and Eir, Pioneer, get it? snicker snicker (yes my electronics teacher was a super dork). Actually he was smart, he pointed out that its important to not look at E as voltage per se, but as energy, sighting a cross reference to water and air flow. His point was to teach us not to think of Ohms Law as an "electrical" formula, but as a physical law of nature. I know its just academic, but this was one of those tiny things that helped me to think independently.
 7th May 2004, 09:18 AM #2 Frank Berry   diyAudio Member     Join Date: Sep 2003 Location: Midland, Michigan "curious, at what point in time did E transpose to V?" Thanks for your observation. I have wondered the same. By the way ... we must have studied under the same Teacher! __________________ Frank
 8th May 2004, 12:25 AM #3 millwood   Account Disabled   Join Date: Apr 2003 Location: US as I recall, E usually means "potential" (what it is relative to, I don't recall). so voltage between two points is really the difference between the two points' potential. or V = delta E. Potential itself will not cause electrons to flow. But he difference in potential will.
 8th May 2004, 11:51 AM #4 pinkmouse   diyAudio Moderator     Join Date: Apr 2002 Location: Rotherham, England Moved to EE, 'cos this is on topic for the site! __________________ Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
Christer
diyAudio Member

Join Date: Sep 2002
Location: Sweden
Quote:
 Originally posted by millwood as I recall, E usually means "potential" (what it is relative to, I don't recall). so voltage between two points is really the difference between the two points' potential. or V = delta E. Potential itself will not cause electrons to flow. But he difference in potential will.

Interestingly, in some countries like Sweden and Germany,
we use U for voltage and V for potential. To add to the
confusion, E is often used for the voltage of a voltage source.

Just don't ask me where the U comes from originally, but I
suspect it has its origin in Germany.

Workhorse
diyAudio Member

Join Date: Dec 2004
Commentable Thoughts

Quote:
 Originally posted by Christer Interestingly, in some countries like Sweden and Germany, we use U for voltage and V for potential. To add to the confusion, E is often used for the voltage of a voltage source. Just don't ask me where the U comes from originally, but I suspect it has its origin in Germany.
YES, thats rite 'U' is incarnation of German Engineering.

Compliments to Christer
ampman

 8th May 2004, 01:41 PM #7 li_gangyi   diyAudio Member     Join Date: Jun 2003 Location: Woodlands Circle here in SG for physics class...we have this crappy ohms law wheel thingy...basically it's based om P=VI and V=IR...we dp use E and V interchangeably though...but for clarity...V is used most of the time during theory and test papers...wonder why the E and V thingy...perhaps originally it was like Current...represented by I and has a unit of A...so Potential Difference would be represented by E and measured in V...I dunno..just speculating... __________________ Kids in the back seat cause accidents...Accidents in the back seat cause kids...
 8th May 2004, 10:03 PM #8 rif   Neither a cowbow nor dog owner diyAudio Member     Join Date: Jan 2003 Location: Southern NJ I believe it's a difference between physicist's and engineer's conventions is all. Same thing with imaginary numbers: physicists use i, engineer's use j but they're both sqrt(-1). What else is different -- hmm...tough to remember so far back to university. **Maybe vector notation--putting the arrow above or below the variable? **mhos vs Siemens?
Pjotr
diyAudio Member

Join Date: Nov 2002
Location: Netherlands
Quote:
 **mhos vs Siemens? [/B]

Hi,

Mho is the reverse of “ohm”, so multiple of them should be smho ???

If I remember well E is used in electrostatics to denote the potential of an electric field and it is used also for electromagnetic emission (i.e antennas): E-field an H-field vectors.

Have a look here:

http://physics.nist.gov/cuu/Units/

and:

http://physics.nist.gov/cuu/Units/units.html

Cheers

 8th May 2004, 11:27 PM #10 Svante   diyAudio Member     Join Date: Feb 2004 Location: Stockholm In Sweden we say U=R*I __________________ Simulate loudspeakers: Basta! Simulate the baffle step: The Edge

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Aussie Amplifiers         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post kaybee Full Range 20 11th November 2006 02:45 AM eddi0 Subwoofers 24 21st October 2006 04:29 PM ptwining Class D 1 13th September 2006 12:11 PM ptwining Class D 36 17th July 2006 02:33 PM alexmoose Tubes / Valves 1 28th April 2006 03:09 AM

 New To Site? Need Help?

All times are GMT. The time now is 03:17 PM.