Page 28 - Basic Electrical Engineering

available in nature are, therefore, transformed into electrical energy and then
transmitted to places where electricity is to be used for doing some work.
Electrical engineering, therefore, has become a discipline, a branch of study

which deals with generation, transmission, distribution, and utilization of
electricity.

Electronics engineering is an offshoot of electrical engineering, which
deals with the theory and use of electronic devices in which electrons are

transported through vacuum, gas, or semiconductors. The motion of electrons
in electronic devices like diodes, transistors, thyristors, etc. are controlled by

electric fields. Modern computers and digital communication systems are
advances of electronics. Introduction of very large scale integrated (VLSI)
circuits has led to the miniaturization of all electronic systems.

Electrical and electronic engineering are, therefore, very exciting fields of
study. A person who is unaware of the contribution of these fields of

engineering and the basic concepts underlying the advancement, will only
have to blame himself or herself for not taking any initiative in knowing the

unknown.
In this chapter, we will introduce some basic concepts, laws, and principles

which the students might have studied in physics. However, since these form
the basis of understanding of the other chapters in this book, it will be good
to study them again.

1.2 ATOMIC STRUCTURE AND ELECTRIC CHARGE

Several theories have been developed to explain the nature of electricity. The
modern electron theory of matter, propounded by scientists Sir Earnest

Rutherford and Niel Bohr considers every matter as electrical in nature.
According to this atomic theory, every element is made up of atoms which

are neutral in nature. The atom contains particles of electricity called
electrons and protons. The number of electrons in an atom is equal to the

number of protons.
The nucleus of an atom contains protons and neutrons. The neutrons carry

no charge. The protons carry positive charge. The electrons revolve round the
nucleus in elliptical orbits like the planets around the sun. The electrons carry