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Recharging and discharging.

  1. Dec 13, 2014 #1
    Electrons naturally flow from lower to higher potential but inside a battery electrons flow against their nature so that's why their potential energy increases that's what EMF is(energy given per coulomb)right?EMF is always of source i.e battery. And battery such as galvanic cell does so by using chemical energy.right?And this is called charging .And then electron spends all these energy throughout the circuit while crossing resistance and at last returns to battery again with all potential energy used up.This process is called discharging .right?
     
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  3. Dec 13, 2014 #2

    NascentOxygen

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    Staff: Mentor

    This chemical reaction that gives rise to the EMF is not referred to here as charging. You could call it galvanic action, or an oxidation reaction that liberates electrons.

    Charging (also known as recharging) occurs when the reversible reaction in a secondary cell proceeds under the application of an externally-sourced current.

    One small but important quibble is that the electrons originating in the cell don't zip around the circuit to quickly return to the positive terminal. They meander along at a surprisingly slow average speed, jostling and pushing ahead of them some of the electrons already present in the conductive wires. A particular electron that leaves the negative terminal may never make it back to the positive terminal; an electron from one of the wires may happily take its place instead.
     
    Last edited: Dec 13, 2014
  4. Dec 13, 2014 #3
    ok just don't take it as recharging and discharging but is this difference between EMF and PD(Voltage)?
    Electrons naturally flow from lower to higher potential but inside a battery electrons flow against their nature so that's why their potential energy increases that's what EMF is(energy given per coulomb)
    .And then electron spends all these energy throughout the circuit while crossing resistance .Whenever they(electrons)cross any resistance their potential energy decreases so this causes potential difference between two points across the resistance.
    So source such as battery provides energy in the form of EMF and then this energy is being used while crossing resistance which results in potential difference.
     
  5. Dec 13, 2014 #4

    NascentOxygen

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    EMF is a term usually applied to the voltage generated by a battery, alternator, PV solar cell, electric eel, thunderstorm cloud, etc. PD is a general term you can use anywhere.
     
  6. Dec 13, 2014 #5
    What about my post 3 is it right?
     
  7. Dec 13, 2014 #6

    NascentOxygen

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    Yes.

    While we'll often represent current as flowing through a battery to complete the circuit's electrical loop, remember in a chemical cell it is ions that are migrating through the solutions, not free electrons.
     
  8. Dec 13, 2014 #7
    Thanks a lot.You cleared all my doubt.
     
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