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Flow of current through zero potential difference

  1. May 20, 2013 #1
    there are two points A and C having a finite potential difference.they are connected by a wire of non zero resistance.a current will flow through the wire.the wire is now removed and a third point B is introduced which has an potential equal to A.a wire is taken which connects A,B,C.will a current flow through the wire?detailed explanation please!
  2. jcsd
  3. May 20, 2013 #2
    As there is a finite potential difference between B and C current will flow between them thus changing the potential at B. So current will also flow between A and B till the three points are at equal potential.
    Last edited: May 20, 2013
  4. May 20, 2013 #3
    but experiments show that a constant current flows through the entire circuit from the very initial moment.any explanation on that part.....?
  5. May 20, 2013 #4
    From your question it seems potential at A,B and C are not kept constant .So in that case ,as swap1996 said , current will flow from B to C reducing the potential at B,and so also from A to B until they are at same potential.

    But if the potential at A,B and C are kept constant (say the case when A and C are connected to the terminals of a cell, and A and B are at same potential and there is a resistance between B and C ) then due to the potential difference between B and C ,current will flow from B and C and so same current should flow from A to B.
    (However in the physical situation of above example the points A and B connected by a wire ,say, wont have same potential due to small resistance an so there will be a finite potential drop.)
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