Flow of current through zero potential difference

[soumyajitnag]

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!

 

[swap1996]

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.

 

[soumyajitnag]

but experiments show that a constant current flows through the entire circuit from the very initial moment.any explanation on that part...?

 

[projjal]

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!

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 experiments show that a constant current flows through the entire circuit from the very initial moment.any explanation on that part...?

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, won't have same potential due to small resistance an so there will be a finite potential drop.)