Electricity is magnetism

By: David Hess (davidwhess.delete@this.gmail.com), December 19, 2021 6:54 pm
Room: Moderated Discussions
anon1 (anon1.delete@this.anon1.com) on December 19, 2021 2:51 am wrote:
> Here is something I do not understand (and sorry if this is very naive, my last exposure to physics of
> electromagnetism was in high school 20 years ago) — if the energy of the electromagnetic field is propagated
> to the LED on the "shortest" path rather along the wire, why is the wire even needed? That is, wouldn't
> it mean that the LED would receive energy even if were not connected to the circuit?

Energy would be transferred for as long as it took the transmission lines to charge.

If the transmission lines were open on their remote ends, then in circuit they appear as a resistance equal to their characteristic impedance until the wave propagating along the transmission line reaches the end and returns, at which point if they are properly terminated by the load, energy transfer ends. Transmission lines are sometimes used in exactly this way in which case they might be called "charge lines".

Things get weird if the load does not match the transmission line impedance because it causes reflections but there is no need to consider that here.
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TopicPosted ByDate
Electricity is magnetismBrett2021/12/14 04:01 PM
  *facepalm* (NT)Ray2021/12/14 05:16 PM
    in fairness what started out trollish turned into a really informative thread (NT)anonymous22021/12/15 06:55 PM
  Electricity is magnetismAnon2021/12/14 06:16 PM
    Electricity is magnetismLightning2021/12/14 06:47 PM
      Electricity is magnetismDavid Hess2021/12/14 10:47 PM
    Electricity is magnetismBrett2021/12/15 12:12 PM
      Electricity is magnetismSimon Farnsworth2021/12/15 02:30 PM
      Electricity is magnetismAnon2021/12/15 03:03 PM
      Electricity is magnetism---2021/12/16 12:19 PM
        Electricity is magnetismAdrian2021/12/16 03:51 PM
  Electricity is magnetismAdrian2021/12/15 05:06 AM
    Sorry for a few typos, I was in a hurry, but the typos do not affect the meaningAdrian2021/12/15 05:40 AM
    Electricity is magnetism2021/12/16 06:22 PM
      Electricity is magnetismEtienne Lorrain2021/12/17 02:44 AM
        Electricity is magnetismBrett2021/12/17 01:44 PM
      Electricity is magnetismAdrian2021/12/17 05:24 AM
        Electricity is magnetism2021/12/17 02:49 PM
          Electricity is magnetismAdrian2021/12/18 03:54 AM
            Electricity is magnetismAdrian2021/12/18 04:17 AM
              Electricity is magnetismanon12021/12/19 03:51 AM
                Electricity is magnetismAdrian2021/12/19 05:13 AM
                Electricity is magnetismDavid Hess2021/12/19 06:54 PM
  Electricity is magnetismzArchJon2021/12/15 11:53 AM
  This video is just really totally wrong..., sorry.Hans de Vries2021/12/15 06:26 PM
    This video is just really totally wrong..., sorry.anon2021/12/16 05:03 AM
  Electricity is magnetismBrett2021/12/19 06:02 PM
    Electricity is magnetismDavid Hess2021/12/19 07:11 PM
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