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
    May 28 '18 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
    May 28 '18 at 14:32
  • \$\begingroup\$ Oh, btw these were the capacitors that were used in distributors so smal... \$\endgroup\$
    – Solar Mike
    May 28 '18 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
    May 28 '18 at 14:57

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\$ May 28 '18 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
    May 28 '18 at 15:10
  • \$\begingroup\$ I don't think the question was quantitative. Besides, C/V is not that complicated :) \$\endgroup\$ May 28 '18 at 15:15
  • \$\begingroup\$ Just a little (not more than 1mg) more seriously, imagine throwing a Van Der Graaf generator :D \$\endgroup\$ May 28 '18 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
    May 28 '18 at 15:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.