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Variation of electric field to produce electric current

  1. Oct 9, 2013 #1
    Theoretically , a change in either electric or magnetic field will cause a current to flow , i am already familiar to Faraday's law of electromagnetic induction , so i tried to search about producing a current using a varying electric field, didn't find anything , i found an interseting apparatus though.
    http://en.wikisource.org/wiki/Alternate_Current_Electrostatic_Induction_Apparatus
    tesla's electrostatic induction apparatus
    My question here is about lenz's law , will this law be applicable here ? I know the law is in case of magnets , but i tried to imagine what will happen if we tried the coil magnet situation where approaching coil to the coil a resisting force will develop , but if we replaced the magnet with an electret ( electrostatic equivalent of permanent magnet), as it approaches the loop the side near the electret will obtain a partial charge opposing to charge of the electret causing it to approach faster.
    In the end of the article tesla wrote "The output of such an apparatus is very small, but some of the effects peculiar to alternating currents of short periods may be observed. The effects, however, cannot be compared with those obtainable with an induction coil which is operated by an alternate current machine of high frequency, some of which were described by me a short while ago." why will the output of such an apparatus was small ? does electric field has smaller influence on electrons than magnetic field?
     
  2. jcsd
  3. Oct 9, 2013 #2
    An electric field will produce a current if there are mobile charges. It's enough to put a conductor in the field and you get a current. A variable field will produce a variable current. But you don't need a variable electric field to have a current or some "exotic" effects.
     
  4. Oct 9, 2013 #3
    i know , but the current will soon stop as it reaches equilibrium , adjusting electronic distributing according to electric field , to keep a current flow , u will need to keep the electric field changing
     
  5. Oct 9, 2013 #4
    How about a resistor connected to a battery? Is the electric field changing in order to keep a constant current?
     
  6. Oct 9, 2013 #5
    You dont understand me, read the article, the thing is : when a + charged object is near a conductor, it will attract electrons , when this object moves relative to the conductor the electrons will move with him, creating current
     
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