Now, we will try to understand the concept of electric current
For that, we will first try to visualize the basic structure of atom of a metallic conductor
Basic nature of metal is that, its atom consists of loosely bonded electrons in its outermost cell
This electron is so loosely bonded with the parent atom that anytime due to a tiny energy
it may detach from the parent atom. This electron is called free electron
A free electron randomly moves here and there inside the metal. Again, when it gets vacant orbit in other atom, it may associate with that atom but
does not stay there permanently, means after some time it may again detach from that atom also
In this way, free electron is detached from atom and after moving randomly inside the
metal body, it associates with another atom and again is detached from there
A metal has plenty of these free electrons inside it even at room temperature
Now, if this metal conductor is connected across a voltage source, these free electrons
come under an electric field and an electric force acts on them
As the electrons are electronegative, they will be accelerated towards the positive end
of the conductor. As a result, these free electrons drift towards the positive end of the metal conductor
As these electrons have negative electrical charge, there is a flow of negative charge
towards the positive end of the metal conductor. The flow of negative charge from negative to positive terminal of the conductor can
be alternatively assumed as flow of positive charge from positive to negative terminal
of the conductor. And the rate of flow of positive charge in respect of time from higher potential terminal
i.e. positive terminal to lower potential terminal or negative terminal of a conductor
is defined as electric current. So hope we get a clear concept of electric current through a metal conductor
Thank you