Electromagnetic Theory


Electrostatics

In this chapter we will discuss on the followings:

1.        Coulomb's Law

2.        Electric Field & Electric Flux Density

3.        Gauss's Law with Application

4.        Electrostatic Potential, Equipotential Surfaces

5.        Boundary Conditions for Static Electric Fields

6.        Capacitance and Capacitors

7.        Electrostatic Energy

8.        Laplace's and Poisson's Equations

9.        Uniqueness of Electrostatic Solutions

10.   Method of Images

11.   Solution of Boundary Value Problems in Different Coordinate Systems

 Introduction

 In the previous chapter we have covered the essential mathematical tools needed to study EM fields. We have already mentioned in the previous chapter that electric charge is a fundamental property of matter and charge exist in integral multiple of electronic charge. Electrostatics can be defined as the study of electric charges at rest. Electric fields have their sources in electric charges.

 ( Note: Almost all real electric fields vary to some extent with time. However, for many problems, the field variation is slow and the field may be considered as static. For some other cases spatial distribution is nearly same as for the static case even though the actual field may vary with time. Such cases are termed as quasi-static.)

In this chapter we first study two fundamental laws governing the electrostatic fields, viz, (1) Coulomb's Law and (2) Gauss's Law. Both these law have experimental basis. Coulomb's law is applicable in finding electric field due to any charge distribution, Gauss's law is easier to use when the distribution is symmetrical.