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Home > Archive > Electrical Engineering > June 2006 > what is the ohms law ?
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what is the ohms law ?
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| raghu 2006-03-05, 11:21 am |
| May i know the difference between V=R I and V = I R. Which equations
is correct for ohms law.
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| Salmon Egg 2006-03-05, 1:21 pm |
| On 3/5/06 6:59 AM, in article
1141570753.330955.251470@p10g2000cwp.googlegroups.com, "raghu"
<raghu.raghu143@gmail.com> wrote:
> May i know the difference between V=R I and V = I R. Which equations
> is correct for ohms law.
>
Because of commutativity (look that up), the two equations are equivalent.
Before getting electrically involved with Ohm's law it would be to your
benefit to understand the mathematics involved. In particular, the
distributive and commutative laws of multiplication.
If you really want to learn something, understand why these mathematical
laws apply to complex numbers. After that, look into situations which which
commutativity is not true.
Bill
-- Ferme le Bush
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| TimPerry 2006-03-05, 2:21 pm |
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"raghu" <raghu.raghu143@gmail.com> wrote in message
news:1141570753.330955.251470@p10g2000cwp.googlegroups.com...
> May i know the difference between V=R I and V = I R. Which equations
> is correct for ohms law.
>
when talking about voltage drop in a conductor, if you want to be understood
by the majority you will refer to I*R as the IR drop.
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| Billy H 2006-03-05, 3:21 pm |
|
"TimPerry" <timperry@noaspamadelphia.net> wrote in message
news:TJ6dnQhcROvzvJbZRVn-jQ@adelphia.com...
>
> "raghu" <raghu.raghu143@gmail.com> wrote in message
> news:1141570753.330955.251470@p10g2000cwp.googlegroups.com...
>
> when talking about voltage drop in a conductor, if you want to be
> understood
> by the majority you will refer to I*R as the IR drop.
>
>
>
isn't you being naughty?
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| E = I times R is the original Ohm's law.
"Salmon Egg" <salmonegg@sbcglobal.net> wrote in message
news:C0305BE5.1C03E%salmonegg@sbcglobal.net...
> On 3/5/06 6:59 AM, in article
> 1141570753.330955.251470@p10g2000cwp.googlegroups.com, "raghu"
> <raghu.raghu143@gmail.com> wrote:
>
> Because of commutativity (look that up), the two equations are
> equivalent.
> Before getting electrically involved with Ohm's law it would be
> to your
> benefit to understand the mathematics involved. In particular,
> the
> distributive and commutative laws of multiplication.
>
> If you really want to learn something, understand why these
> mathematical
> laws apply to complex numbers. After that, look into situations
> which which
> commutativity is not true.
>
> Bill
>
> -- Ferme le Bush
>
>
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| Roy L. Fuchs 2006-03-05, 9:21 pm |
| On Sun, 05 Mar 2006 21:43:43 GMT, "Pop" <nobody@devnull.spamcop.net>
Gave us:
>E = I times R is the original Ohm's law.
Wrong!
TOFU retard! Learn to refrain from top posting in Usenet, IDIOT!
http://en.wikipedia.org/wiki/Toppost
Ohm's Law is:
The amount of current flowing in a circuit made up of pure resistances
is directly proportional to the electromotive forces impressed on the
circuit and inversely proportional to the total resistance of the
circuit.
THAT is the "original Ohm's Law!
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| Don Kelly 2006-03-05, 9:21 pm |
| ----------------------------
"Pop" <nobody@devnull.spamcop.net> wrote in message
news:jYIOf.928$ci1.502@trndny08...[color=darkred]
>E = I times R is the original Ohm's law.
>
> "Salmon Egg" <salmonegg@sbcglobal.net> wrote in message
> news:C0305BE5.1C03E%salmonegg@sbcglobal.net...
So?
E=IR is equivalent to I=E/R or R=E/I
Same thing written different ways.
Ohm just stated a linear (constant R) relationship between E and I
Why complicate it with differences that don't exist?
--
Don Kelly @shawcross.ca
remove the X to answer
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| TimPerry 2006-03-05, 9:21 pm |
| > >> May i know the difference between V=R I and V = I R. Which equations
>
> isn't you being naughty?
>
im too old for naughty.
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| Tom Grayson 2006-06-07, 12:21 pm |
| I think you need to get away from behind your computer and mix with some
real people again. your Interpersonal skills are on a sharp decline.
Tom
"Roy L. Fuchs" <roylfuchs@urfargingicehole.org> wrote in message
news:slvm029a1hdaed2fqvpa27qj7gn6ll840u@4ax.com...
> On Sun, 05 Mar 2006 21:43:43 GMT, "Pop" <nobody@devnull.spamcop.net>
> Gave us:
>
>
> Wrong!
>
> TOFU retard! Learn to refrain from top posting in Usenet, IDIOT!
>
> http://en.wikipedia.org/wiki/Toppost
>
>
> Ohm's Law is:
>
> The amount of current flowing in a circuit made up of pure resistances
> is directly proportional to the electromotive forces impressed on the
> circuit and inversely proportional to the total resistance of the
> circuit.
>
> THAT is the "original Ohm's Law!
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"raghu" <raghu.raghu143@gmail.com> wrote in message
news:1141570753.330955.251470@p10g2000cwp.googlegroups.com...
> May i know the difference between V=R I and V = I R. Which equations
> is correct for ohms law.
Both are correct for ohms law. (assuming V = voltage, I = current, and R =
resistance)
And unless "R" has direction, both will give the same answer.
If R has direction, then the magnitude will be the same, but the direction
of the voltage will reverse as R reverses.
(resistance rarely has direction)
----
In background, not addressing emf or the fundamental vectors of
electro-magnetism or other things that make it messy--
a) "Ohms law" says
(english language) that there is a relationship between charge flow and
applied voltage and impedance. (Or in the special case of a pure resistive
circuit, resistance).
(math language), V=IR where V=Voltage, I= charge flow, R= impedance
(resistance)
b) In lay terms, a quantity that has magnitude and direction is a vector.
Voltage is a vector because it has direction (polarity). Current is a
vector because it has direction (flow).
If resistance has no direction, it is a scalar, and since a scalar times a
vector is a vector, the above equations give the same answer and direction
(polarity/flow).
If resistance/impedance has direction, then since the voltage and current
are also vectors, the multiplication has to be a cross product. Reversing
order of vectors in a cross product will reverse direction of the resultant
vector.
Laws of vector mathematics.
fwiw..
>
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| nvmani2006@gmail.com 2006-06-08, 6:21 pm |
| IR=RI , Therefore, V=IR or V=RI, or V=IR=RI
Shall we end with this conclusion?
hob wrote:[color=darkred]
> "raghu" <raghu.raghu143@gmail.com> wrote in message
> news:1141570753.330955.251470@p10g2000cwp.googlegroups.com...
>
> Both are correct for ohms law. (assuming V = voltage, I = current, and R =
> resistance)
>
> And unless "R" has direction, both will give the same answer.
>
> If R has direction, then the magnitude will be the same, but the direction
> of the voltage will reverse as R reverses.
>
> (resistance rarely has direction)
>
> ----
>
> In background, not addressing emf or the fundamental vectors of
> electro-magnetism or other things that make it messy--
>
> a) "Ohms law" says
>
> (english language) that there is a relationship between charge flow and
> applied voltage and impedance. (Or in the special case of a pure resistive
> circuit, resistance).
>
> (math language), V=IR where V=Voltage, I= charge flow, R= impedance
> (resistance)
>
> b) In lay terms, a quantity that has magnitude and direction is a vector.
> Voltage is a vector because it has direction (polarity). Current is a
> vector because it has direction (flow).
> If resistance has no direction, it is a scalar, and since a scalar times a
> vector is a vector, the above equations give the same answer and direction
> (polarity/flow).
> If resistance/impedance has direction, then since the voltage and current
> are also vectors, the multiplication has to be a cross product. Reversing
> order of vectors in a cross product will reverse direction of the resultant
> vector.
>
> Laws of vector mathematics.
>
>
> fwiw..
>
>
>
>
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<nvmani2006@gmail.com> wrote in message
news:1149801437.685148.317050@u72g2000cwu.googlegroups.com...
> IR=RI , Therefore, V=IR or V=RI, or V=IR=RI
> Shall we end with this conclusion?
your syllogism has a faulty assumption of IR = RI. Therefore your
conclusion is in error.
I x R = - R x I
and Ir = rI.
Therefore, V=IR = -RI and V = Ir = rI
You certainly can end with that conclusion.
>
> hob wrote:
=[color=darkred]
direction[color=darkred]
and[color=darkred]
resistive[color=darkred]
vector.[color=darkred]
times a[color=darkred]
direction[color=darkred]
current[color=darkred]
Reversing[color=darkred]
resultant[color=darkred]
>
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