Electric current is the movement of electric charge in a conductor in one direction due to the influence of external forces. Because naturally in a material or substance, the erratic movement of cargo direction. Electric charge can be either an electron, ion or keduanya.Arus electricity can occur with media solids, liquids, and gases. As you already know, that the electric charge is measured in coulombs (C), where 1 Coulomb is equal to the amount of cargo by a 6.24 x 10 18 electrons, and the charge of an electron is e = 1.602 x 10 -19 Coulomb.
One Coulomb is a matter of a number of electrons passing through the conductor sauatu every second, while the constant current flow rate at one ampere. Electric current in a conductor is a directional movement of electrons number from one end to the other. The number of electrons in the Coulomb equal to 6.24 x 10 18 electron fruit. The flow of one Coulomb per second equals one ampere. It’s like a water flow rate in gallons per minute.
Coulomb measure the amount of electrons. Amper measuring the rate of flow of electric current. Amper not measure the electron. But Amper has a relationship with Coulomb 1/1. It means that if there is 10 amperes flows through the same point in one second with 10 Coulomb. From the above explanation can be defined that the unit of electric current is coulomb per second. However, the unit of electric current that is commonly used is the ampere, where one coulomb per second = one ampere or I = Q / t where I is the epitome of an electric current.
The units of ampere electric current is taken from the name of Andre Marie Ampere (1775-1836).
Figure 1.15 Electric Current in Electrical Conductor
The movement of electrons on an object during a certain period of time will lead to an energy which is then referred to as an electric current. Suppose that in a conductor, if
– N is the number of free electrons in each cubic meter of conductor
– V is the velocity of axial perge-friend electrons in meters / second
– A is the cross sectional area of the lawyer-conductivity
– E is the magnitude of the charge of each electron.
Then the volume conductor traversed by the movement of electrons in a time dt is: vAdt and the number of electrons moving in the volume are:
nvAdt
So the magnitude of the charge that penetrate the conductor cross-section in a time dt is
dq = nvAedt.
Definition of electric current (I) is the amount of charge per unit time, so:
Definition of current density is the amount of flow per unit cross-sectional area, so:
Suppose,
J = 1,55.106 A / m2
n = 10 29 for copper
e = 1,62.10 -19 C
then y = 9,7.10 -5 m / s