Electric current and quantity of electricity

Every atom is composed of protons, neutrons and electrons. The protons bears positive electrical charge, there is no electrical charge on the neutrons. Both protons and neutrons are contained within the nucleus which is in the center of the item. Electrons are not found in the nucleus, which bears a minute negatively electrical charge.

 Atoms of different materials are different from wachother by having different numbers of protons, neutrons and electrons. An atom would be electrically balanced if it has an equal number of protons and electrons, as we know that the positive and negative charges cancel each other out. When there are more than 2 electrons in an atom the electrons are arranged into shells and these shells are at various distances from the nucleus.

Powerful forces of attraction bound all the atoms together, these forces exist between the nucleus and its electrons. Electrons revolving in the outer shell of an atom, are attracted to their nucleus not as that powerfully like electrons whose shells are nearer the nucleus. An atom may lose an electron; the atom, after losing electron the atom called an ion, is not now electrically balanced, but is positively charged and is thus able to attract an electron to itself from another atom.

Free Electron is one that moves from one atom to another atom and such random motion can continue for indefinite period of time. However, if we apply electric pressure or voltage across any material there is a large tendency for electrons to move in a particular direction. Such a free movement of free electrons is refers to as drift, and this preliminarily constitutes an electric current flow. Thus current is the rate of movement of charge. OR Flow of electrons is called Electric Current.

There is a material known as Conductor which contains electrons that are loosely attached to the nucleus and has the ability to easily move through the material from one atom to another. Insulators are those materials whose electrons are held firmly to their nucleus.

The coulomb C is the unit which is used to measure the quantity of electrical charge Q (where 1coulomb=6.24×1018 electrons). If the drift of electrons in a conductor takes place at the rate of one coulomb per second the resulting current is said to be a current of one ampere. Thus, 1 ampere=1 coulomb per second or 1 A=1 C/s Hence, 1 coulomb=1 ampere second or 1 C=1 As Generally, if I is the current in amperes and t the time in seconds during which the current flows, then I ×t represents the quantity of electrical charge in coulombs, i.e. quantity of electrical charge transferred,