a large number of electrons are present in metals. why there is no current in absense of potential a

Asked by  | 10th Aug, 2009, 01:54: PM

Expert Answer:

current flows through a wire or metal when there is potential difference across its terminal.The electrons initially are bound to the metal lattice but not to any individual atom. Even with no external electric field applied, these electrons move about randomly due to thermal energy but, on average, there is zero net current within the metal. Given an imaginary plane through which the wire passes, the number of electrons moving from one side to the other in any period of time is on average equal to the number passing in the opposite direction.

When a metal wire is connected across the two terminals of a DC voltage source such as a battery, the source places an electric potential across its terminal.


Answered by  | 10th Aug, 2009, 02:02: PM

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