Basics tips:

·         The simple model of matter is made up of atoms which have positively charged nuclei orbited by negatively charged electrons.Given sufficient energy,an electron can be dislodged(means remove from a fixed position)from its atom.


·         Think of electricity as the flow of energy carried by the movement of electrons dislodged from its atom.


·         An electrical circuit is formed when there is a closed path around which the electron's flow.


·         In electrical circuits, we are interested in the movement of energy from one location to another.


·         Some elements in a circuit supply energy. These are called sources and some elements in a circuit expand energy. These are called Loads(or)Sinks.


·         The total energy supplied is equal to the total energy expanded.


·         We typically measure energy somewhat indirectly energy is measured in Joules(J).Power is energy per unit time. Power is measured in watts(W).A watt is equal to one joule per second.


·         1 w = 1 J/S ;    Ex: A 100 w light bulb expands 100 joules for each second.


·         The number of electrons flowing in a circuit is called "current". It is denoted as 'I' and measured in 'Ampere's(A)'.An Ampere is one coulomb of electrons per second.


·         1 coulomb = 6.24*10^18 electrons.


·         The amount of energy per electron is called voltage .Voltage is denoted as 'V'.It is measured in 'volts'.


·         1 volt = J/c (Joule/coulomb).


·         So to determine the power we take the product of the number of electrons flowing(i.e. current ) and the energy per electron(i.e. voltage) and we should get a measure of power(wattage).


·         simply the product of voltage and current is called power.


·         In units V*A = W (or) (Joule/coulomb)*(coulomb/sec) = (Joule/sec).



 




EmoticonEmoticon