steady current and its topics

• Flow of charge of current per unit time is called current
• Convenction current direction is always opposite to the direction of flow of electrons
• Current density is defined as the ratio of the current to the cross section area
• When the electric field is established between the two ends of the conductor, the free electrons experience a force. The motion of the electrons get accelerated, but the speed of the electrons does not increase continuously. The electrons in the conductor collide and collide again with positive ions of the conductor such that they lose the energy which appear in the form of heat. Altogether this field does not give any acceleration to the motion of the electrons such that constant velocity of electrons is maintained. That constant velocity is called drift velocity.