1. Engineering Electromegnetic

2. SUB : Engineering Electromagnetic Topic : Conductors Department : Electronics and communication Name : Parmar Taruna M. Enroll No : 130430111110 Guided By, j.m bhoot

3.  A conductor is something which allows electricity to flow through.  Exam.: Scissors, Paper clip, Aluminum foil,Iron,Steel,Copper.  In Conductors Valence electronics are present.  When an electric field is applied,then these electrons start moving which constitute an electric current.  Conductors are the materials which allow the current to flow very easily. Fig. Energy band diagram for conductors

4.  This is due to the large number of free electrons present in conductors.  Look at the energy band diagram of conductor show fig. for metals like copper, alumina, etc.  There is no “forbidden gap” present between the valence and conductors bands.  Therefor even at room temperature, a large number of free electrons are present and available for conduction.

5.  When a charge Q is placed in an electric field E, it experiences a force  Gives by F=QE. If this charge is an electrons, then Q=-e so that F=-e E. Due to negative sign of elections charge it is clear that the force acting on the electron is in opposite direction to that of eclectic field intensity E. If there is no opposition or resistance to the motion of electron, then the velocity of electron will increase indefinitely with the time t provided the electron field E is constant.

7.  Lets us now consider a conductor placed in a static electric field, as show fig. the free electrons in the conductor moves opposite to the direction line of electric field.  Thus a negative surface charge forms on the boundary accompanied by an equal amount of positive surface charge show in fig.,since the conductor as a whole is neutral. Fig : Effect of Field Conductor

8. * Imagine that you have a solid metal ball or sphere and you place charge inside of it. * How fast this charge arrives at the surface can be calculated using the term relaxation time. * Time taken by charges to travel to the surface is represented by relaxation time. Using the relations,

9.  In electrostatic fields, following principle are applicable to conductors:  Within a Conductor, charge or change density(pv c/ m3) is zero and a surface charge density (ps c/m3) is present on the other surface of the conductor.  The tangential component of external electrical field intensity as well as electric flux density is zero.  The conductor surface is an equipotential surface.  The normal component of electric flux density is equal to surface charge density on the conductor surface.

15. 1.www.wikipedia.in 2.www.google.com 3.www.yahoo.com References