Question

a large number of free electrons are present in metals yet no current flow in the absence of electric potential across it . explain the statement with reason.

Answer 1

Without potential difference,the electrons do not flow in the same direction,instead they flow randomly thus cancelling out charges as one goes forward then at the same time one may go backward and cancel it out.

Answer 2

Electrons flow only when there is potential difference. It flows from lower potential to higher potential ( ie from - to +). Potential difference provides acceleration to the electrons which appears in the form of kinetic energy.

The flow of something takes place only if there is difference between two points

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