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A few electricity questions.

  1. Aug 10, 2009 #1

    PrincePhoenix

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    1-When a person gets electrocuted by accident, why can't he remove himself from the wire?
    2-Is there any relation between voltage and the strength of the electromagnetism induced? Not a mathematical relation. Just want to know does a high voltage result in a strong electromagnet?
    3-Does AC induce electromagnetism?
     
  2. jcsd
  3. Aug 10, 2009 #2
    1. Electricity causes muscles to contract. If someone touches a live wire with the palm of his hand, the electricity may cause his hand muscles to contract causing him to grasp the wire and not let go. It is safer to test a wire with the back of your hand.

    2. Electromagnetism is often expressed in terms of Amp-Turns. In other words electromgnetism is proportional to the number of turns in the electromagnet and the number of amps flowing through it. Amps are determined by the voltage divided by the impedance of the electromagnet. So yes, indirectly there is a relation between voltage and amperage. High voltage can result in a strong electromagnet only if the electromagnet has sufficiently low impedance and there is enough amperage available.

    3. The meaning of this question is a little unclear to me. The short answer is yes and so does DC.
     
  4. Aug 10, 2009 #3

    negitron

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    Because he's dead (you don't survive electrocution, by definition.)
     
  5. Aug 10, 2009 #4
    it should ! But if it is Parallelly Combinated then it wont create magnetic field !
     
  6. Aug 10, 2009 #5

    Born2bwire

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    I can't tell if you are being facetious here but any AC signal is an electromagnetic wave, hence they have both electric and magnetic fields.
     
  7. Aug 10, 2009 #6
    I apologise for any kind of mistake ! :((
     
  8. Aug 11, 2009 #7

    PrincePhoenix

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    Thanks for the answers.
     
  9. Aug 11, 2009 #8
    actually bro i was trying to remind BIOT SAVART'S LAW there! [tex]\vec{B}[/tex] = Magnetic field
    [tex]\vartheta[/tex] = l ^ B

    [tex]dB\propto[/tex] [tex]sin\vartheta[/tex]
    and when its parallel and direction is opposite to the flow of electricity (I) [tex]\vartheta[/tex] = 180
    sin 180 = 0 so dB = 0
    correct me bro if i am wrong As i missed the lecture!
     
  10. Aug 11, 2009 #9

    Born2bwire

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    All AC currents are propagated by electromagnetic waves, there will always be both electric and magnetic fields.

    If what you are describing are two parallel wires with one being the return path then there still will be magnetic fields. The only way you could cancel out the fields would be if the wires are colocated in which the superposition of currents would be zero, the trivial case.

    Biot-Savart is not applicable here since it is only valid for time-independent currents.
     
    Last edited: Aug 11, 2009
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