Prev: Most meteorites contain fossil bone remains
Next: Will simple questions defeat Porat .. lets see if they do.
From: Peter Duncanson (BrE) on 28 Mar 2010 07:55
On Sun, 28 Mar 2010 18:15:53 +1200, "PaulJK"
<paul.kriha(a)paradise.net.nz> wrote:

>Hatunen wrote:
>> On Sat, 27 Mar 2010 09:29:58 +0000, Mike Barnes
>> <mikebarnes(a)bluebottle.com> wrote:
>>
>>> Hatunen <hatunen(a)cox.net>:
>>>> On Fri, 26 Mar 2010 08:06:21 +0000, Jonathan de Boyne Pollard
>>>> <J.deBoynePollard-newsgroups(a)NTLWorld.COM> wrote:
>>>>> [...]
>>>>> energy being delivered, the amount of which is
>>>>> determined by the wattage,
>>>>
>>>> I suppose one might casually say that, but in fact the power
>>>> (wattage) is a function of the current and resistance, not
>>>> vise-versa.
>>>
>>> How so?
>>
>> Power is a result of passing a current through a resistance;
>> current and rsistance aren't a result of power.
>
>It could be also said that
>the current is a result of applying voltage to a resistance.
>:-)

That is one way of creating a current. Another is with a varying
magnetic field as in generators and in the secondary windings of
transformers.

--
Peter Duncanson, UK
(in alt.usage.english)
From: jimp on 28 Mar 2010 11:47
Hatunen <hatunen(a)cox.net> wrote:
> On Sun, 28 Mar 2010 02:00:32 -0000, jimp(a)specsol.spam.sux.com
> wrote:
>
>>In sci.physics Hatunen <hatunen(a)cox.net> wrote:
>>> On Sat, 27 Mar 2010 19:19:59 +0000, Mike Barnes
>>> <mikebarnes(a)bluebottle.com> wrote:
>>>
>>>>Hatunen <hatunen(a)cox.net>:
>>>>>On Sat, 27 Mar 2010 09:29:58 +0000, Mike Barnes
>>>>><mikebarnes(a)bluebottle.com> wrote:
>>>>>
>>>>>>Hatunen <hatunen(a)cox.net>:
>>>>>>>On Fri, 26 Mar 2010 08:06:21 +0000, Jonathan de Boyne Pollard
>>>>>>><J.deBoynePollard-newsgroups(a)NTLWorld.COM> wrote:
>>>>>>>>[...]
>>>>>>>>energy being delivered, the amount of which is
>>>>>>>>determined by the wattage,
>>>>>>>
>>>>>>>I suppose one might casually say that, but in fact the power
>>>>>>>(wattage) is a function of the current and resistance, not
>>>>>>>vise-versa.
>>>>>>
>>>>>>How so?
>>>>>
>>>>>Power is a result of passing a current through a resistance;
>>>>>current and rsistance aren't a result of power.
>>>>
>>>>But it seems to me equally valid to say that current is the result of
>>>>generating power in a resistance. You can't pass current without
>>>>generating power,
>>>
>>> Well, actually you can in a superconductor.
>>
>>Nonsense.
>>
>>A resistance dissipates power, it doesn't generate it.
>>
>>An ideal superconductor would have 0 resistance, hence isn't a resistance,
>>and dissipates 0 power.
>
> You win, I suppose. But I was specifically addressing your
> sentence, "You can't pass current without generating power"

I never said that.

You have to generate power somewhere to have voltage and current, but it
doesn't happen in a resistance, it happens in the voltage source.


--
Jim Pennino

Remove .spam.sux to reply.
From: Glenn Knickerbocker on 28 Mar 2010 15:45
On Sun, 28 Mar 2010 18:42:14 +0100, Jonathan de Boyne Pollard wrote:
>> Voltage and current are proportional to each other. It is therefore
>> sufficient to say that damage is proportional to one of them.

Well, one of them squared.

>Wrong, as already explained. You're missing out a fair number of
>dimensions. You make my point to M. Knickerbocker for me. You are
>definitely trying to argue that voltage alone is sufficient,

He argued nothing of the sort. He described how the effect varies with
voltage (or current, or power), independently of the other factors.

�R http://users.bestweb.net/~notr/zangelding.html "When there's
a nuclear attack, that's when buckets are used." --Tim Brown, IUSD
From: Doctroid on 28 Mar 2010 22:24
In article <homphq$91l$1(a)news.eternal-september.org>,
"PaulJK" <paul.kriha(a)paradise.net.nz> wrote:

> Voltage and current are proportional to each other.
> It is therefore sufficient to say that damage is proportional
> to one of them.

Only in materials and voltage/current ranges where Ohm's "law" is
obeyed. And if damage is occurring, it probably isn't.

--
Sig available on request.

- Doctroid
From: Doctroid on 28 Mar 2010 22:26
In article <28cvq5thba4ntr25kfgdnlk07lvha4ftd5(a)4ax.com>,
Glenn Knickerbocker <NotR(a)bestweb.net> wrote:

> On Sun, 28 Mar 2010 18:42:14 +0100, Jonathan de Boyne Pollard wrote:
> >> Voltage and current are proportional to each other. It is therefore
> >> sufficient to say that damage is proportional to one of them.
>
> Well, one of them squared.
>
> >Wrong, as already explained. You're missing out a fair number of
> >dimensions. You make my point to M. Knickerbocker for me. You are
> >definitely trying to argue that voltage alone is sufficient,
>
> He argued nothing of the sort. He described how the effect varies with
> voltage (or current, or power), independently of the other factors.

Another words, he was trying to convey the essential idea underlying
partial derivatives: finding how a function of many variables changes
when one variable changes and the others are held fixed.

--
Sig available on request.

- Doctroid
First  |  Prev  |  Next  |  Last
Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Prev: Most meteorites contain fossil bone remains
Next: Will simple questions defeat Porat .. lets see if they do.