Page 13 - Basics of Electrical, Electronic and Communication

Chapter 1

Basic Concepts in Electrical

Engineering

Basic concepts of electrical engineering are discussed in this chapter.

1.1 Introductory concepts and basic elements

Electric current
Electric current is the rate of flow of electric charges. Electrons are
negatively charged particles and their flow in conductors results in
electric current.
By definition, current i,

dq
i = (1.1)
dt
If Q is the amount of charge flowing through a conductor in T
seconds, then, current I is given by the expression,
Q
I = (1.2)
T
The unit of charge is Coulomb. 1 Coulomb = 6.24 ×10 18 electrons.
The unit of current is Ampere, A. 1 Ampere = 1 Coulomb/sec.

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