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Why does electric current always flow from positive to negative?It is said that current...

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kavya--kammana | Student, Grade 12 | (Level 1) Valedictorian

Posted March 30, 2012 at 10:17 PM via web

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Why does electric current always flow from positive to negative?

It is said that current flows from positive terminal to negative terminal....but it is actually the negative electrons flowing to positive as the positive electrons doesn.t move......the why is the direction from +ve to -ve....it should be negative to positive.....please give me the right answer..please..................

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najm1947 | Elementary School Teacher | (Level 1) Valedictorian

Posted March 31, 2012 at 1:58 AM (Answer #1)

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The notion of flow of current from +ve to -ve is based on the concept that positive if some thing where you have something excess and negative is something which is in shortage.  This is however not true in case of an electrolytic cell where +ve terminal lacks electrons and the -ve terminal has excess electrons. Actual situation is described below:

Inside a electrolytic or galvanic cell the electrons flow from the Carbon Rod (anode) to the Zinc  Shell (cathode) and by virtue of that there is shortage of electrons on the anode and it gets a positive charge. On the other hand, electrons accumulate on the cathode and it gets the negative charge. When anode and cathode of the cell are connected by a wire through a lamp, the electrons (current) actually flows through the circuit from cathode (-ve terminal) to anode (+ve terminal) in the wire and lamp and from +ve to negative in the electrolite.

You can see from the above example the actual status of current flow but it has been made a convention to say that the current flows from +ve to -ve terminal. However the factual position is otherwise.

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bandmanjoe | Middle School Teacher | (Level 1) Senior Educator

Posted March 31, 2012 at 12:28 AM (Answer #2)

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The flow of electric current occurs because we have a high potential of electrons gathered at the positive terminal and a low potential of electrons at the negative terminal.  It doesn't have so much to do with the charge associated with each one as it does with the fact you have an inequality between amounts of electrons available.  When you complete the circuit by turning on the switch, the electrons flow naturally from the high potential to the low potential, which is from the positive pole to the negative pole.  Think of it this way:  if you have a stream of water, and you build a dam to hold back the water, you get a buildup, a reserve of water behind the dam.  When you open the floodgate of the dam, you start a "flow" of water from the excess water you have available.  This water quite readily flows to the lower levels in front of the dam, where the water levels are low.  It is the same with the flow of electric current through a circuit.

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