Date: Thu Mar 19 08:44:25 2009 ** **Back to Contents ** ------------------------------------------------------------------------ **

Author: Paul Nord

Subject: Re: Power Lines and cows?

Post:

Sorry... that might have been a little too flip.
It doesn't matter that the source of the field is also rotating.
Whether you are being difficult or dense surely is of consequence. No
slight was intended there.

I should say more about the claim. Consider a rotating metal shaft.
If I place a strong magnet very near to the end of the shaft, there
will be some magnetic field passing through the shaft at an angle to
its direction of motion. The electrons in the shaft will be caused to
move by that field and will setup a potential difference. Next
consider that I have the same magnet attached to the end of the
shaft. The magnetic field in the shaft will be virtually unchanged.
Why then, would it not produce the same potential when the shaft is
rotated? How would the electrons "know" whether the magnet is
attached or removed at some distance? All we can say about the forces
on the electrons is A) they are being accelerated around in a circle
and B) they are in a magnetic field.

Paul

On Mar 18, 2009, at 10:24 PM, Paul Nord wrote:

> It doesn't matter.
>
> On Mar 18, 2009, at 5:48 PM, Bernard Cleyet wrote:
>
>> Are you being difficult or am I too dense?
>>
>> So is the field. There is no relative motion between the field and
>> the conductors.
>>
>> bc
>>
>>
>> On 2009, Mar 18, , at 15:00, Paul Nord wrote:
>>
>>> What do you mean they don't move?
>>> Of course they move. We're all moving. The earth is spinning.
>>>
>>> Paul
>>>
>>> On Mar 18, 2009, at 2:43 PM, Bernard Cleyet wrote:
>>>
>>>> I thought we were discussing power lines that don't move WRT the
>>>> earth and its mag. field.
>>>>
>>>> bc must reread recent posts?
>>>>
>>>>
>>>> On 2009, Mar 18, , at 12:25, Paul Nord wrote:
>>>>
>>>>> BC,
>>>>>
>>>>> No... or probably not much. But the earth rotates. And a
>>>>> conductor moving in a magnetic field will produce an induced
>>>>> voltage.
>>>>>
>>>>> Paul
>>>>>
>>>>> On Mar 18, 2009, at 2:08 PM, Bernard Cleyet wrote:
>>>>>
>>>>>> The earth's mag. field rotates?
>>>>>>
>>>>>> bc
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 2009, Mar 18, , at 07:40, Paul Nord wrote:
>>>>>>
>>>>>>>
>>>>>>> Do north-south power lines induce a DC current as they spin
>>>>>>> through earth's magnetic field?
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>


From tap-l-owner@lists.ncsu.edu Thu Mar 19 08:44:25 2009
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