Electric current 


  • The  flow of free electrons (or charge) in a definite direction is called electric current.


  • The flow of electric current you can show in below diagram....                                                              


  • The copper strip has large number of free electrons. When electric pressure voltage is applied, the free electron being negatively charged start moving towards the positive terminal around the circuit.

                     
  • This directed slow of electrons is called electric current.


  • Conventionally, the direction of the electric current is taken along the direction of motion of positive charges. When current is caused by electrons (e.g. in metals), the direction of current is opposite to the direction of electrons flow.


  • Important point:-  in relative scale the spacing between they nucleus and wellness electron is vast. If a copper atom could be magnified until the electrons were as large as coins , the valance electrons would be several kilometers away from the nucleus. This relatively large distances dictates that valence electron is only weakly attached to the nucleus.