Friday, December 12, 2014

What is a Watt ?

Any time we analyze an Energy business, we come across the terms Mega Watt and Giga Watt . So what is actually a “Watt” . Following Post gives technical details of this term.

Watt is the unit of power . It primarily measures the rate of Energy consumed. Thus 1 Watt = 1 joule / second. One Watt is also defined as the current flow of one ampere with voltage 1v.

Ampere : Ampere is the unit of electric current , named after Andre-Marie Ampere of France. One ampere is defined as the current that flows with electric charge of 1 coulomb per second.

Coulomb : It is the fundamental unit of electrical charge , basically it is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of charges , positive or negative charge. Similar charges repel and opposites react. So what creates a positive charge? If an object has an excess of electrons then its negatively charged and is otherwise positively charged or neutral. 1 coulomb = 6.24 x 10 18 electrons charge.

Farad : It measures capacitance of a capacitor which when charged with 1 coulomb of electricity produces a potential difference of 1 volt.

Henry : Is the Unit of Inductance , named after Joseph Henry who discovered Electromagnetic induction independently at about the same time as Michael Faraday. Definition : If the rate of charge of current in a circuit is 1 ampere per second and the resulting Electromotive force (EMF) is 1 volt then the inductance of the circuit is 1 Henry..

Ohm : Ohm named after Greg Simon Ohm , its defined as a resistance between two points of a conductor when a constant potential difference of 1 volt applied to these points produces in the conductor a current of 1 ampere , the conductor not being seat of any Electromagnetic force.

F = (A x S) / V = J / V2 = (W x S) / V2 = C / V = C2 / J = C2 / (N x M)
  =(S2 x C2) / (M2 x kg) = (S4 x A2) / (M2 x kg) = S / Ohm = S2 / H

F = Farad , A : Ampere , V = Volt , C = Coulomb , J = Joule , M = Meter ,
N = Newton , H= Henry , S = Second , W = watt , kg = Kilogram