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Does a current flow in a circuit due to voltage (potential difference between the 2 points of the battery) or due to the attraction of unlike charges (e.g. an electron and the positive terminal of the battery).

Also, imagine there is an ideal circuit with a 9V battery with no internal battery resistance, superconducting wires and no resistors. Since V=IR, 9=I(0). What will be the current in this case?

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    \$\begingroup\$ As your equation suggests, the current would be (theoretically) infinite. \$\endgroup\$ Feb 14, 2016 at 11:57
  • \$\begingroup\$ Also, if there is no voltage and resistance, e.g. just a superconducting wire lying around, there should be no current. However, since V=IR and V=0 and R=0, I=anything. Isn't that a paradox \$\endgroup\$ Feb 14, 2016 at 12:02
  • \$\begingroup\$ @RaphaelLow, no paradox. Super conductors don't have "zero reistance" (try putting AC current through them, they blow up). Current in super conductors is a pair electron wave. So with enough physics you can prove that the electrons are either moving or not, but that they had to have something to push them in the first place to move (inertia still holds true). \$\endgroup\$
    – Dave
    Feb 14, 2016 at 12:40
  • \$\begingroup\$ In physics, when our models give infinities, it is usually a sign that the model has broken down and doesn't apply to the conditions considered. In a superconducting ring, a current set up initially will flow forever because the electrons are not scattered; however, there is no potential difference in this case. @Dave's comment that superconductors have finite resistance is not quite correct. There are limits on the current/magnetic flux density for which the superconductive state can exist, however. And infinite currents can't flow in practice because everything has some inductance. \$\endgroup\$ Feb 14, 2016 at 16:15
  • \$\begingroup\$ @OleksandrR. I was more commenting on the fact that you shouldn't consider it to be a perfect conductor, as it isn't. The electrical resistance is "zero" in so much that an electron's velocity is undisturbed (it's inertial state is what it was last left at by an outside force). Past that we get quantum wonders. \$\endgroup\$
    – Dave
    Feb 14, 2016 at 16:54

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There is no difference between the two things you stated. Un-alike charges are attracted due to electric field. Electric fields produce potential differences. Potential differences is what we call Voltage. See, one and the same; we just like using voltages because they are a scalar value versus electric field/attraction which is a vector value (vector calculus is not fun to do to solve simple stuff.)

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Electrical current in a circuit or any conductor in general is due to a potential difference allowing atoms to "pass" electrons to each other, which results in a global trend of moving charged particles in one direction.

What makes a particular element more conductive than another is the ability of the atoms to easily (=without too much external energy needed) free or catch electrons. In macro-size world, it means that to create an electrical current of same value, a good conductor will need less potential difference than a bad conductor (or good dielectric). Hence the notion of "resistance".

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