Previous in Forum: The Relationship Between V and I   Next in Forum: Power Consumption of AC's In Terms of TR
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
12 comments
Rate Comments: Nested
msmir116
Associate

Join Date: Dec 2006
Location: Doha Qatar
Posts: 43

V is directly prop to I or Inversly?

08/04/2010 2:04 AM

the contradictory relation between v an I

V=P/I- inversely proportional in case of power sources and or transformer

V=I*R - directly proportional in all loads

need ur comments

__________________
 Please save the power for Next Generation- Do ur bit
Register to Reply
Pathfinder Tags: V is directly prop to I or Inversly?
This discussion was "closed" on 08/04/2010 8:52 AM. No new comments are allowed.
Message from admins:
This thread has been closed because it is a duplicate. Please add your comments to the original thread: http://cr4.globalspec.com/thread/58162

Good Answers:

These comments received enough positive votes to make them "good answers".
Anonymous Poster
#1

Re: V is directly prop to I or Inversly?

08/04/2010 2:51 AM

P = I2R

Substitute into your eq (1) to get eq (2)
Register to Reply
msmir116
Associate

Join Date: Dec 2006
Location: Doha Qatar
Posts: 43
#2

Re: V is directly prop to I or Inversly?

08/04/2010 3:03 AM

from where u get p=I sq* R??

from v=I*R only wats the point of puting in above to get the same frm whr u gt it?

__________________
 Please save the power for Next Generation- Do ur bit
Register to Reply
PWSlack
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#4
In reply to #2

Re: V is directly prop to I or Inversly?

08/04/2010 3:05 AM

Since P=VI and V=IR, then P=I2R by substitution.

__________________
 "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
PWSlack
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#3

Re: V is directly prop to I or Inversly?

08/04/2010 3:03 AM

These are fundamental relationships in electricity. They 'just are'. Why the question?

__________________
 "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
kvsridhar
Guru
India - Member - New Member

Join Date: Sep 2009
Location: Temporarily at Ashburn, VA
Posts: 2744
Good Answers: 164
#5

Re: V is directly prop to I or Inversly?

08/04/2010 3:45 AM

Assuming you are serious,

__________________
 Nothing worthwhile can ever be taught, it can only be learnt.
Register to Reply
user-deleted-1105
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#6

Re: V is directly prop to I or Inversly?

08/04/2010 3:45 AM

As I'm feeling generous (dunno why)
R is simply defined as V/I so there can be no question there.
Power is self evidently V*I As 1amp at 9 volts has considerably less power than 1amp at 100v. This can be simply tested.
The rest is just formula manipulation.
You need to do some simple experiments until you thoroughly understand this and the simple maths involved in manipulating the equations.
If you really can't grasp it, then find another job/hoby/course of study.
Forget transformers and AC for now, because if you don't get it with DC you don't have a chance with AC.
Oh and before you start trying to disprove formulae, you need to get them right.
Del

__________________
 health warning: These posts may contain traces of nut.
Register to Reply
msmir116
Associate

Join Date: Dec 2006
Location: Doha Qatar
Posts: 43
#7

Re: V is directly prop to I or Inversly?

08/04/2010 3:55 AM

hey duded i really understand that all very well

but its just i wanted to share a thing in my mind... inverse as well as direct relations if v and i are perfect.. theoriticaly as well as practically

sridhar.. i knw the formula

__________________
 Please save the power for Next Generation- Do ur bit
Register to Reply Score 1 for Off Topic
Tobugrynbak
Guru

Join Date: Oct 2008
Location: Deepest Darkest Rutherford Oz
Posts: 951
Good Answers: 145
#8

Re: V is directly prop to I or Inversly?

08/04/2010 4:43 AM

Seems like another post turtle thread.

__________________
 There are two reasons for a man to do a thing, One that sounds good, and the real one...
Register to Reply Off Topic (Score 5)
2
user-deleted-1105
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#9

Re: V is directly prop to I or Inversly?

08/04/2010 4:51 AM

You only make this 'ambiguity' appear by introducing P which of course has I as part of it. Real 'proportionality' would have unrelated factors or constants, not terms which are masking the term you are claiming is inverse.

It's like saying my height (H) is inversely proportional to how tall I am (T) by including a spurious factor Z which is actually T2.

H=Z/T wow look I've proved it

Del
(You're lucky I'm at work..it's not my own time. I'll get the company to bill you)

__________________
 health warning: These posts may contain traces of nut.
Register to Reply Good Answer (Score 2)
No more Good Answers.
msmir116
Associate

Join Date: Dec 2006
Location: Doha Qatar
Posts: 43
#10

Re: V is directly prop to I or Inversly?

08/04/2010 5:53 AM

thanks Del

dat was the perfect reply

Real 'proportionality' would have unrelated factors or constants, not terms which are masking the term

thanks

__________________
 Please save the power for Next Generation- Do ur bit
Register to Reply
Anonymous Poster
#11

Re: V is directly prop to I or Inversly?

08/04/2010 6:39 AM

Qatar is very hot and humid place. isnt it??
Register to Reply Score 1 for Off Topic
msmir116
Associate

Join Date: Dec 2006
Location: Doha Qatar
Posts: 43
#12
In reply to #11

Re: V is directly prop to I or Inversly?

08/04/2010 7:28 AM

very very.. h and very humid

__________________
 Please save the power for Next Generation- Do ur bit
Register to Reply
Register to Reply
Have a Different Question?
12 comments
This discussion was "closed" on 08/04/2010 8:52 AM. No new comments are allowed.
Message from admins:
This thread has been closed because it is a duplicate. Please add your comments to the original thread: http://cr4.globalspec.com/thread/58162

Good Answers:

These comments received enough positive votes to make them "good answers".
Copy to Clipboard

Users who posted comments:

Anonymous Poster (2); kvsridhar (1); msmir116 (4); PWSlack (2); Tobugrynbak (1); user-deleted-1105 (2)

Previous in Forum: The Relationship Between V and I   Next in Forum: Power Consumption of AC's In Terms of TR

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Electrical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (54 right now)
Show Members
Advertisement