Re: Magnets

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "jimmy hynes by way of Terry Fritz <twftesla-at-qwest-dot-net>" <chunkyboy86-at-yahoo-dot-com>


oh, makes sense now. you tricked me into thinking you weren't too sure of the
answer. i didnt think about how little charged could be stored on a sphere
compared to the amount of electrons in wire. and i guessed it had to do with
electrons moving from atom to atom. 

 Tesla list 
>
> wrote:  
> Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz " 
>
> Tesla list wrote: 
> > 
> > Original poster: "jimmy hynes by way of Terry Fritz "
>
> > 
> > the magnetic field is created when electrons flow through an conductor, 
> not by 
> > only moving a charged conductor. electrons actually move VERY slowly(even 
> > though signals can travel at the speed of light). if a charged conductor 
> > created a magnetic field when it was moved then it would have ALOT of extra
> > momentum and other weird things that obviously dont happen. im pretty sure 
> > thats the answer to Antonio's question. i didnt think i would ever be able
> to 
> > answer any question that Antonio would have
>
> I'm sorry to say, but your answer is incorrect... 
> Charges that mov! e don't care if they are inside a conductor or not. 
> A spark can be deflected by a magnetic field, and generates a magnetic 
> field around it (otherwise how would it be deflected?). Electrons 
> moving in vacuum generate magnetic fields around them, and your 
> monitor's CRT works because of this. Charged objects in movement 
> do generate magnetic fields. The weird things that you mention happen, 
> but are almost unobservable in normal conditions. To produce a barely 
> observable movement in a compass needle, you need to place close to it 
> a wire transporting a few mA of current. Or, you have to make a few 
> millicoulombs per second of charge to move close to it. Let's suppose 
> that a wire with 10 mA of current produces a detectable movement 
> in a needle placed 1 cm from it (this works. To simplify the 
> comparison, imagine that the wire has 1 cm of radius). 
> A charged ball with its center at the same distance from the needle 
> would have at most 1 cm of r! adius. 
> But a ball with 1 cm of radius can store at most 0.0! 33 microcoulombs, 
> with a surface electric field of 30 kV/cm, the limit for breakdown in 
> normal air. 
> To produce the effect of 10 mC/second, in a brief pulse, it would 
> have to move at 10e-3/0.033e-6 = 303 km/s! 
> A quite difficult experiment...
>
> Antonio Carlos M. de Queiroz
>
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> JImmy
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