Since current is just buckets of charge passing through a point in space per unit time, and a capacitor is a literal bucket of charge, I had some questions in mind.

  • Is throwing a charged capacitor considered electrical current? Like if the capacitor is say 1 inch in length, has 1C of charge, and is flying through the air at 100 inches per second, does that mean 100 amps of current?
  • If so, would magnetic fields be generated? Would it actually take more effort to throw a charged capacitor than to throw an uncharged one, since the supposed magnetic field stores part of the work done in throwing?
  • If the capacitor is left on the desk, and an observer moves instead, would he/she see magnetic fields, but a stationary one doesn't?

I know this is silly and trivial, but I don't have iron filings and a large supercap.

  • 1
    \$\begingroup\$ Do(n't) charged capacitors attract/repell each other? Why (not)? What does that say about their total charge? \$\endgroup\$
    – Joren Vaes
    Commented May 28, 2018 at 14:30
  • 3
    \$\begingroup\$ When throwing a charged capacitor across the workshop at someone while shouting “catch” the reaction was usually the best... but no we never did that :) ... \$\endgroup\$
    – Solar Mike
    Commented May 28, 2018 at 14:32
  • \$\begingroup\$ Oh, btw these were the capacitors that were used in distributors so smal... \$\endgroup\$
    – Solar Mike
    Commented May 28, 2018 at 14:36
  • \$\begingroup\$ I was going to answer based on what happens if you throw half a capacitor (ie a single charged object) around, but you've already accepted an answer. See en.wikipedia.org/wiki/Oxford_Electric_Bell \$\endgroup\$
    – pjc50
    Commented May 28, 2018 at 14:57

1 Answer 1


One plate on a capacitor is positively charged and the other plate is negatively charged. Net charge on a capacitor is therefore zero. Does that help? Do we see magnetic fields generated by the charged capacitor if we placed it at the equator (rotating about 1000 mph).

  • \$\begingroup\$ What if the capacitor is very big, like 10m long? :) And if you have a twisted pair, don't you see a very weak magnetic field right close to the wires? \$\endgroup\$
    – user76844
    Commented May 28, 2018 at 14:48
  • \$\begingroup\$ @GregoryKornblum ask your self how much voltage is needed to achieve 1 coulomb with plates 10m apart. Yes, twisted pairs have a weak magnetic field close to 1 wire relative to the other. \$\endgroup\$
    – Andy aka
    Commented May 28, 2018 at 15:10
  • \$\begingroup\$ I don't think the question was quantitative. Besides, C/V is not that complicated :) \$\endgroup\$
    – user76844
    Commented May 28, 2018 at 15:15
  • \$\begingroup\$ Just a little (not more than 1mg) more seriously, imagine throwing a Van Der Graaf generator :D \$\endgroup\$
    – user76844
    Commented May 28, 2018 at 15:19
  • \$\begingroup\$ Throwing a VDGG doesn't sound trivial but if you did throw it and also spun it you would likely create an nice EM wave at the spin frequency. \$\endgroup\$
    – Andy aka
    Commented May 28, 2018 at 15:29

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