LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
ELECTROMAGNETICS
LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Electrostatics- electric charges at rest (static electricity)
Involves electric charges, the forces between them, and their behavior in
materials
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LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Charge- in an atom, a positively charged nucleus is surrounded by
electrons
The protons (+) in the nucleus attract the electrons (-), while the
electrons repel each other
This attraction and repulsion behavior gives an object its charge.
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LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Properties of Atom- All electrons are identical, with the same mass and
same quantity of charge
The nucleus is composed of protons (all of which are also identical) and
neutrons (neutral)
Atoms usually have as many electrons as protons, so the atom has a zero
net charge.
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LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Ions- If the total positive charge balances the total negative charge, the
atom is neutral
If a particle is removed from the atom, it becomes an ion
Positive Ion: Has lost one or more electrons and has a net positive
charge
Negative Ion: Has gained one or more electrons and has a net negative
charge
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LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Conductor: Materials which allow electric charge to flow freely
Metals are good conductors because their outer electrons are not bound
tightly
Insulator: Materials which do not allow electric charge to flow freely
(i.e. glass, rubber)
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LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Semiconductor: Materials that can be made to behave as either a
conductor or an insulator of electricity
i.e.) germanium, silicon
Superconductor: Material that has infinite conductivity at low
temperatures so that charge flows through it without resistance
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LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Conservation of Charge
Electrons are never created nor destroyed, but are simply transferred
from one material to another
Electrons are always transferred in whole – they cannot be divided into
fractions of electrons
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LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Coulomb’s Law
The force between two charges depends on the magnitude of the
charges and the distance between them
qq
F=k
1 2
d
2
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Units of charge = Coulomb (C)
k is a proportionality constant called the Coulomb
constant
k = 9,000,000,000
𝑁 𝑚2
or
𝐶
9
𝑁 𝑚2
9
x10
𝐶
9
LICEO DE CAGAYAN UNIVERSITY
Rodolfo N Pelaez Boulevard, Kauswagan, 9000, Cagayan de Oro City
COLLEGE OF ENGINEERING
CIVIL ‖ ELECTRICAL ‖ INDUSTRIAL ‖ COMPUTER ‖ ELECTRONICS ENGINEERING
CHAPTER 1- INTRODUCTION
Example:
Charge of an Electron
-19
qe = -1.6 · 10 C
Charge of a Proton
-19
qp = +1.6 · 10 C
Two electrons are a meter apart. What is the force between
them? What direction is it in?
d = 1m
qp = -1.6*10-19C
9
qe = -1.6*10-19C
2
2
-19
-19
F = (9*10 N*m /C ) (-1.6*10 C)* (-1.6*10
2
(1 m)
F = 2.3*10
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C)
-28
N
10