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Re: [Phys-l] induced electric field



Methinks it is not that simple. The fields sare usually generated in an enclosed space, and the effect of the boundaries are crucial. Antenna design is one of the higher arts.
I had a taste of this one evening when another teacher and I, fooling around in the lab, tried to duplicate the settup where Hertz discovered radio waves. We never succeeded, even with a copy of sthe famous Britannica article describing his setup.
Regards,
Jack

"Trust me. I have a lot of experience at this."
General Custer's unremembered message to his men,
just before leading them into the Little Big Horn Valley




On Tue, 24 Nov 2009, Brian Whatcott wrote:

Perhaps it will be easier if I develop the idea in several steps:
1)An ordinary radio receiver may use a coil wound on a ferrite core
as an antenna.
2) Whatever antenna can receive radio waves can transmit radio waves.
3) Therefor a device which can produce a time varying magnetic field
can radiate radio waves.
Moreover...
4) A device which can carry a time varying electric wave,
can similarly radiate radio waves.

OK?

Brian W

Jack Uretsky wrote:
Radio waves from a betatron? Tell me more, please.



A (slowly) increasing magnetic field gives rise to an electromagnetic
field, in the nature of things, that radiates at the speed of light -
we call them radio waves.

Brian W

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