Summary Notes of Electrical Technology

Summary Notes of

ELECTRICAL
TECHNOLOGY

Zuraida Binti Kamaruddin
Robiah Binti Udin

Suhardi Bin Che Ahmad



Summary Notes of
Electrical Technology

Zuraida Binti Kamaruddin
Robiah Binti Udin

Suhardi Bin Che Ahmad

POLITEKNIK SULTAN IDRIS SHAH
KEMENTERIAN PENGAJIAN TINGGI

ALL RIGHTS RESERVED
Issue 2022

All rights reserved. Any part of this book may not be reproduced, Perpustakaan Negara Malaysia Cataloguing-in-Publication
stored for withdrawal or convertible into any form or by any device Data
whatsoever, whether by electronic, mechanical, refilming and
recording, etc. Without prior written permission of the book writer. Zuraida Kamaruddin, 1978-
Summary Notes of Electrical Technology /
The views or opinions contained in this publication do not necessarily Zuraida Binti Kamaruddin, Robiah Binti Udin,
reflect the policy, policy and erection of books and book writers shall Suhardi Bin Che Ahmad.
not be liable for any loss suffered by any party making action or Mode of access: Internet
residual based on information in this publication. eISBN 978-967-2860-28-0
1. Electrical engineering.
Published by : 2. Electric circuits.
Politeknik Sultan Idris Shah 3. Electronics.
Sg Lang 45100 Sg Air Tawar 4. Government publications--Malaysia.
5. Electronic books.
Selangor I. Robiah Udin, 1967-. II. Suhardi Che Ahmad, 1980-.
III. Title.
03-32806200 621.3

03-32806400

Laman Web : https://psis.mypolycc.edu.my

TABLE OF CONTENTS

I II

ACKNOWLEDGEMENT i ABSTRACT ii
iii v
III IV

TECHNICAL SLANG USED STANDARD
FREQUENTLY IN THE ELECTRICAL UNITS OF
ELECTRICAL INDUSTRY MEASURE

• SHORT NOTES / SUMMARY • SHORT NOTES / SUMMARY
• EXAMPLE • EXAMPLE

V 01

MULTIPLES AND SUB- vii INTRODUCTION TO 1
MULTIPLES ELECTRICAL CIRCUIT

• SHORT NOTES / SUMMARY • SHORT NOTES / SUMMARY
• EXAMPLE • EXAMPLE

TABLE OF CONTENTS

02 03
DC EQUIVALENT CIRCUIT NETWORK THEOREM
21 41
• SHORT NOTES / SUMMARY • SHORT NOTES / SUMMARY 85
• EXAMPLE
• EXAMPLE 123

04 05
CAPACITOR AND INDUCTOR AND
CAPACITANCE 67 INDUCTANCE

• SHORT NOTES / SUMMARY • SHORT NOTES / SUMMARY
• EXAMPLE • EXAMPLE

06 07
MAGNETIC CIRCUIT
ELECTROMAGNETISM QUESTIONS
AND ELECTROMAGNETIC 107

INDUCTION
• SHORT NOTES / SUMMARY
• EXAMPLE

TABLE OF CONTENTS

08 09

ANSWERS 127 REFERENCES 140

10 143

AUTHOR

• ZURAIDA BINTI KAMARUDDIN
• ROBIAH BINTI UDIN
• SUHARDI BIN CHE AHMAD

ACKNOWLEGMENTS

As a servant of Allah SWT, the Most Generous, the Most Forgiving, I
bow to you. As a result of Allah SWT's blessing and Alhamdulillah, we
as authors have been able to put together this ebook : Summary
Notes of Electrical Technology.

Our thanks go out to Sultan Idris Shah Polytechnic for their
assistance. Sultan Idris Shah Polytechnic is supporting this ebook,
giving us the authors the chance to publish an interactive ebook on
technical topics, particularly Electrical Technology. May this ebook
benefit all walks of life. We owe a debt of gratitude to everyone of
our colleagues who shared their knowledge and experience
throughout the course of creating this ebook.

Finally, we'd want to thank our family for their constant support,
love, prayers, and encouragement while we worked on this ebook's
development. We want to thank everyone who helped make this
ebook possible, whether they were involved directly or not.

Everyone's support is much appreciated.

i

ABSTRACT

This Summary Notes of Electrical Technology ebook explains the focus
of the overview in summary notes related to Electrical Technology.
The concept of the ebook used is interactive in the form of
infographic elements are included to facilitate all levels of society to
understand Electrical Technology in general. This ebook also
introduces some technical slang that is often used in the industry,
especially involving the electrical industry and units of measurement
of multiples and sub multiples in the measurement of electrical
circuits and electrical equipment. This ebook contains six topics
related to Electrical Technology. Each title in this book describes a
summary note in addition to some examples that are described in
detail for the understanding of all communities. In addition, each
question posed clearly describes the answer to that question. This
makes it easier for the community or certain groups to understand
each question and answer clearly and in detail as well as the
infographic elements to attract the interest of the community and
certain groups to read this interactive technical ebook.

ii

Technical Slang Used Frequently in the Electrical Industry

CIRCUIT 1 PASSIVE NETWORK
2 The term "passive network" refers to a
Any passage in which an electrical current 3
may travel, or is designed to flow, is known 4 system in which no EMF sources are
as a circuit. In a circuit, there are both active present.
and passive components.
ACTIVE NETWORK
LINEAR CIRCUIT
One or more EMF sources are present in an
An Ohm's law-compliant linear circuit is one
in which the parameters do not vary with 5 active network.
voltage or current. The characteristics of a
nonlinear circuit fluctuate in response to BILATERAL CIRCUIT
changes in voltage and current in this circuit.
When current flows in either way, a circuit is
PARAMETER said to be bilateral if its attributes are the

There are many different types of parameters 6 same in both directions. For instance, a
in an electrical circuit (For Example bilateral transmission line is the norm.
Resistance, Capacitance And Inductance).

iii

Technical Slang Used Frequently in the Electrical Industry

UNILATERAL CIRCUIT 1 LOOP
2 The term "loop" is used to refer to a circuit in
Any circuit in which the properties or 3
characteristics change depending on the 4 which each element or node is encountered
direction of operation is referred to as a just once.
unilateral circuit. A diode rectifier, for
instance, can only rectify in one direction. MESH

NODE No additional loop can be found inside the

When two or more circuit components are 5 mesh.
joined together at a node, they form a circuit.
BRANCH
ELECTRONIC COMPONENT
A branch connects two nodes in a network.
The building blocks of any electronic system
and may be used in a variety of industries, 6
including electronics. These are the building
blocks of electronic and electrical circuits. In
order to connect to the circuit, these parts
have at least two terminals. Active, passive,
and electromechanical applications may all
be used to categorise electrical components.

iv

Standard Electrical Units of Measure

Electrical Parameter Measuring Unit Symbol Description
V or E
Voltage Volt I or i Unit of Electrical Potential
R or Ω V=I×R
Current Ampere G or ℧
Unit of Electrical Current
Resistance Ohm C I=V÷R

Conductance Siemen Unit of DC Resistance
R=V÷I
Capacitance Farad
Reciprocal of Resistance
G=1÷R

Unit of Capacitance
C=Q÷V

v

Standard Electrical Units of Measure

Electrical Parameter Measuring Unit Symbol Description
Q
Charge Coulomb Unit of Electrical Charge
L or H Q=C×V
Inductance Henry W
Z Unit of Inductance
Power Watts Hz VL = - L (di/dt)

Impedance Ohm Unit of Power
P = V × I or I2 × R
Frequency Hertz
Unit of AC Resistance
Z2 = R2 + X2

Unit of Frequency
ƒ=1÷T

vi

Multiples and Sub-multiples

Prefix Symbol Multiplier Power of Ten

Terra T 1,000,000,000,000 1012
Giga G 1,000,000,000 109
Mega M 1,000,000 106
kilo K 1,000 103
none None 1 100

vii

Multiples and Sub-multiples

Prefix Symbol Multiplier Power of Ten

centi c 1/100 10-2
milli m 1/1,000 10-3
micro µ 1/1,000,000 10-6
nano n 1/1,000,000,000 10-9

pico p 1/1,000,000,000,000 10-12

viii

01
Introduction to

Electrical
Technology

1

Introduction to Electrical Circuit

Definition Electrical Switch Circuit
Circuit
In an electrical circuit, the flow of The function of a switch is to
electrons remains uninterrupted 2 connect or disconnect an electric
because it is a closed loop of circuit. Despite the fact that we
conducting material. use switches for a variety of
appliances on a daily basis—
DC Lighting Circuit lights, fans, hair dryers, and
more—we seldom inspect the
Using a DC lighting system, DC connections established within
electricity is sent to the LED DC the switch circuit itself.
load. As a consequence, the
circuit is more trustworthy, more Thermocouple Circuit
consistent, and more efficient
than the conventional method. There are two metal wires, one
Eliminating the AC/DC for sensing and the other for
converters results in a quieter DC reference, which are linked at
circuit and a longer mean time one end (the hot junction) and
between failures. then terminated at a known
temperature at the other end (the
cold junction) to form a
thermocouple circuit (reference
temperature).

Basic Terms of Circuit Diagram

Voltage and Potential Resistance Current
Difference
• Electrical charge flow inside a circuit • The rate at which electrical charge
▪ An electrical charge stores the
may be prevented by a material's moves or flows; expressed in Amperes
potential energy of a power source. ability to impede or block the passage (with an I for intensity), this quantity).
Electrons are "pushed" through a of current. The circuit element which Electrons (the negative atom particles)
conductor by the voltage, and the does this perfectly is called the are "pushed" around a circuit by the
higher the voltage is, the more “Resistor”. voltage source, which causes a
effective it is in "pushing" electrons constant and uniform flow (also
across a specific circuit. • Greek symbol (, Omega) Ohms (k = known as a drift).

▪ Electric current, which moves 103) and Mega-ohms (M = 106) are • In reality, electrons flow from the
prefixes used to represent Kilo-ohms
electrons from one node or point to and Mega-ohms. Consider the fact supply's negative (–ve) terminal to its
another by moving energy, may be that resistance can only be positive in positive (+ve) terminal, but
thought of as a potential energy, value. conventional current flow assumes
which is the effort necessary to that the current flows the other way
transport electrons through a circuit. • Symbol : around to make circuits easier to
understand.
▪ Symbol :
• Symbol :

3

Basic Terms of Circuit Diagram

DC Current (Direct Current) AC Current (Alternating Current)

▪ In comparison to alternating current, direct current is simpler • The periodic shift in direction of charge flow is referred to as an alternating

to grasp. Instead of oscillating back and forth, DC delivers a current. Because the current is reversed, the voltage level is likewise
steady voltage or current that is not affected by external reversed. AC is used to provide electricity to homes, businesses, and other
factors. structures.

▪ There are two methods to make DC : • An alternator is a device that generates alternating current (AC). Alternating
a. Using a "rectifier," which is a device that converts AC to DC, an
current is generated by an unique sort of generator in this gadget.
AC generator with a "commutator" may create direct current.
• A magnetic field creates a current in a wire by spinning it in a magnetic field.
b. Batteries produce DC via a chemical process that occurs
A wind turbine, a steam turbine, running water, or any other method may
within the battery. be used to turn the wire. Alternating voltage and current may be seen on
the wire because the wire rotates and changes magnetic polarity.
▪ Sample Waveform of DC :
▪ Sample Waveform of AC :

4

Construction on a Breadboard

There are metal spring clips on the
breadboard's face underneath each

of the breadboard's holes.

The breadboard's face is covered
with metal spring clips, which
connect leads put into the
breadboard.

Five holes in a vertical column are
connected by a connecting pattern
that connects every five holes in a

horizontal column.

Did you know,
another name of
5 breadboard?

Series Circuit Construction on a Breadboard

6

Parallel Circuit Construction on a Breadboard

7

Active and Passive Component

Diode Resistor

Transistor Capacitor

Integrated Inductor
Circuit
etc
etc
Passive Component
Active Component
8

Active and Passive Component

Basic Active Component Passive Component

Nature of source Active components deliver power or Passive elements utilizes power or
energy to the circuit. energy from the circuit.

Example Diode, Transistors, SCR, Resistor, Capacitor,
Integrated Circuit, etc. Inductor, etc.

Function of the Energy-producing devices that Equipment for storing electricity or
component generate voltage or current. current as a kind of energy.

Power Gain They are capable of They are incapable of
providing power gain. providing power gain.

Flow of current Active components can Passive components cannot
control the flow of current. control the flow of current.

Requirement of Operational requirements need the use They don't need to rely on any outside
external source of an external source. resources to carry out their tasks.

Nature of energy As a source of energy, Passive components use energy as a
active components. result of their passive nature.

9

Difference Between Cell and Battery

Single-cell devices are used to transform Typically, a battery consists of a collection
chemical energy into electric power. of cells.

A cell may be classified as a reserve, wet, Cell Battery A battery may be main or secondary,
or dry cell based on the kind of depending on whether or not it can be
10
electrolytes it contains. The molten salt recharged.
type is also included in the cell.
Batteries are often made up of a large
It is common for cells to be light and number of cells, which makes them heavier
compact since they contain just one unit.
and more cumbersome.
For a shorter length of time, a cell provides
electricity. Powerful batteries may be used for a long
time.
The majority of the time, a cell is employed
for simpler activities that use less energy. The majority of the time, a battery is
It is utilised in slamps, clocks, lights, etc. reserved for more taxing duties. There are
several applications for this component:
The majority of the time, cells may be inverters, automotive inverters, and more.
found for a reasonable price.
Batteries are a lot more expensive than they
used to be.

Batteries Connected

in Series Connection = +
in series + ⋯ +

Symbol : E Same e.m.f value
=
Schematic
Symbol of Cell n = no of cells

11 Circuit Types

Batteries Connected

in Parallel Connection = =
in parallel = ⋯ =

Symbol : E e.m.f =
electromotive

force

Schematic Circuit Types
Symbol of Cell

12

Ideal and Real Battery

01 02

Contain Contain e.m.f., E

e.m.f., E and internal

resister, rint

03 04

E Ideal = E E real = E – (I x rint)

Internal resistance of a battery is increased by series connection cells, but it is decreased by parallel
connection cells. A genuine battery's terminal output voltage is the same as the e.m.f. voltage with no load,

but it lowers somewhat in full load for the terminal output voltage.

13

Total Internal Resistance of
Different Cell Connection

Series VS Parallel

Cell Connections Cell Connections

Internal Resistance, r int Internal Resistance, r int
11
= 1 + 2 + 3 + ⋯ + =
= = 1 1 1 1
1 + 2 + 3 + ⋯+
n = no of

e.m.f., E =
n = no of
= 1 + 2 + ⋯ + e.m.f., E

14 = 1 = 2 = ⋯ =

Example 1 : Series Connection

. . . .

e.m.f., E 02 Internal resistance
= + +
01
=1K+1K+1K
= + +
= . + . + . =
= .
@ = x n
@ = n = x 3
= . x 3
= . =

Did you know,
why E x n and r x n ?

15

Example 2 : Series Connection

. . . .

e.m.f., E

01

= + +
= . + . + .
=

Internal resistance

02 = + +

= 1 K + 200 Ω + 1 K
= .

16

Example 3 : Parallel Connection.

. . . .

02 Internal resistance, = , =

S1 = + + @ =

= + 200 + 200 = x 3

= Ω = Ω

S2 = + + @ =
= + 200 + 200 = x 3

= Ω = Ω

= + = +


=



= Ω

e.m.f., E

01 = + + @ = 1 2 = 600 600
= . + . + . 1 + 2 600 + 600

= . @ = Ω

= + +
= . + . + .

= .

= = = .

17

Example 5 : Parallel Connection

, Ω .

Internal resistance, = ,

S1 02 = , = ,

S2 = + = + = Ω
= + = + = Ω
= + = +

S3 = + + = + +
+



= + +
( + ) +
01 e.m.f., E = = = = = ( + )

= +  = + + = + +
= + =  − . =
 . = + = + +
= +
= + .  = + − = + −
 − =
= +  − = =
= +  =
= = Ω

18

Example 5 :

1. Calculate the total e.m.f. and total internal resistance of the following circuit below.
2. The battery has a total internal resistance of 100 mΩ and a total e.m.f. of 12V. Suppose that all of the cells

that make up the battery are linked in parallel and have a resistance of 10 Ω a piece. The battery is made
up of about how many cells. These cells′ connections should be shown in a diagram.

e.m.f., E

1 = = = = = =

Internal resistance

= + + + + = + + + +


= =


= . Ω

2 100 cells
=

@ . =
= 100

=

19

Example 6 :

There are four cells in a series−parallel battery, which is made by connecting two series groups of two cells
each, and then connecting those two parallel groups. Calculate the total emf and total resistance of the
battery assuming each cell has a 3 V emf and 0.55 Ω internal resistance.

e.m.f., E

1 = + = + =

= + = + =
= = =

Internal resistance

2 = + = . + . = . Ω

= + = . + . = . Ω

= 1 2 = 1.1 1.1 = . Ω
1 + 2 1.1 + 1.1

20

02
DC Equivalent

Circuit 02

21

Electric Circuit

Complete Electric Circuit Open Circuit

It is a closed-end connection Electric There is no current flowing 03
that allows current to flow through the circuit since 04
from the source all the way there is open circuit (switch
through to the sink and back is open).

01 again. Voltage supply (V), A conductor with no
electric current (I), and resistance value will cause
resistance are all required in a short at the load. Because
the circuit (R). of this, the flow of current
through the system is
There are no voltage sources Circuit greater. Fuse burns in most
short-circuit situations.
or load resistance in this
Short Circuit
02 circuit, hence it's classified as
an open circuit. Non-complete
circuits will not allow for

current flow, even if the

circuits are perfectly

balanced. Non-complete

circuits come in two varieties:

Short and open circuits.

Non Complete Electric Circuit

22

Simple Circuit

Schematic Diagram and
Real Circuit

Battery that is Battery Resistor Current produces by
connected in series the battery from
Ohm’s Law :
with resistor as a I = V/R
load.
Circuit
Knowing the Connection :
current, can simply
Series
determine the Connection.
voltage drop from

Ohm’s Law :
V = IR

23

Resistance and Resistivity

Resistance Resistivity

Definition The property of a Definition It is described as a
material that makes it material's ability to
Formula & difficult for electrons to Formula & withstand a certain
Unit move through it. Unit amount of force.


= Ω = Ω.

Various Length, cross-section area Various Temperature.
Factors of conductor and Factors

temperature.

Did you know,

What sizes do resistors

come in?

24

Example 1 : Resistance and resistivity

1. Calculate the resistance of a 10 m long conductor if it has cross sectional area of 5 2 and
resistivity of 0.6 10−5 Ω-m.

ANS :
0.6 10−5 10

= = 5 10−6 = Ω

2. What would be the resistivity pf 4 m length of conductor wire if its resistance is 1 kΩ and the

cross-sectional area is 1 mm².

ANS :

1 103 1 10−6 Ω
= = 4 = µ

3. A 5 m long wire possesses a radius of 1 mm and resistivity of 0.8 10−4 Ω/m. Calculate the

resistance of the wire.

ANS :
= Πr2 = Π x (1)2= 3.142 mm2 = . −
0.8 10−4 5
= = 3.142 10−6 = . Ω

25

Ohm’s Law Triangle

Unit for
Ohm’s Law

VOLTAGE CURRENT RESISTANCE
26

Resistor in Series and Parallel Circuit

R1 TOTAL CIRCUIT TOTAL V R1 R2 R3
R2 RESISTANCE RESISTANCE

V CURRENT CURRENT = + +
R3 TOTAL TOTAL
VOLTAGE
= + + IT = V/RT & IT = V/RT & TOTAL
IT = IR1 = IR2 = IR3 IT = IR1 + IR2 + IR3
VOLTAGE VT = VRI = VR2 = VR3
TOTAL

VT = VRI + VR2 + VR3

27

VDR vs CDR

01 Circuit CDR Current Divider Rule IR2
-Parallel Circuit-
V1 V2
01 Circuit
E
IR1

V3 02 IR1, IR2, IR3 (Based circuit above)

02 V1, V2, V3 (Based circuit above) IR1 = X
V1 = ( ) x +

+ + IR2 = X
+
V2 = ( ) x
VDR Did you know,
+ + What the formula CDR for
28
V3 = ( ) x three resistors?

+ +

Voltage Divider Rule
-Series Circuit-

Example 2 : Series Circuit

, , , = Ω,
= Ω, = Ω =

ANS : 4. VR3

1. Total Resistance, RT

= + + = = = = .
= + +
IR1 =
= Ω IT = . Ω

2. Total Current, IT = V/RT VR3 IR2 = 9.6 V

@

= = Using VDR,

=
= 0.48 A + +

3. IR1 and IR2
= + +

= = = . = = .


29

Example 3 : Series Circuit

, , , = Ω,
= Ω, = Ω =

ANS :

1. Total Resistance, RT 4. VR3

= + + = = = = .
= + +
IR1 IR2 =
= Ω IT VR3 = . Ω

2. Total Current, IT = V/RT = 4.8 V
@

Using VDR,

= = =
+ +

= 0.48 A
= + +
3. IR1 and IR2

= = = .
= = .

30

Example 4 : Parallel Circuit

, , , = , = Ω,
= Ω = Ω

ANS : 3. IR1 and IR2

1. Total Resistance, RT

= + + = = = = ,

=
+ + = = =

= IR1 IR3
VR2 = = = .


= Ω

2. Total Current, IT = V/RT 3. VR2

= = = = = =
=

= A

31

Example 5 : Parallel Circuit

, , , = , = Ω,
= Ω = Ω

ANS :

1. Total Resistance, RT 3. IR2 and IR3

= + + = = = = ,

=
+ + = = = .

=
= = = .

VR3
= Ω
4. VR3
2. Total Current, IT = V/RT

= = = = = =
=

= A

32

Example 6 : Series - Parallel Circuit

, , , = Ω,
= Ω, = Ω, = Ω =

ANS : 2. Total Current, IS = VS/RT

1. Total Resistance, RT

= = = =
+ .
IR2
VR1 = 0.65 A @ 650x − @ 650 mA
= = . Ω
IR4

VR3

3. IR2 and IR4

= = = .
= .

= + +
= + + .

= . Ω

33

Example 6 : (Continue) Series - Parallel Circuit

, , ,
= Ω, = Ω, = Ω, = Ω =

3. IR2 and IR4 4. VR1 and VR3
(IR2 using CDR), IR2=0.65 A
= X - CDR
+
= + X

= + .
IR2
= + . VR1
= . = .
IR4
= . = . VR3 =
= . Ω
4. VR1 and VR3 Did you know,
why VR3 = VR4 ? = 4.4 V
= = = .
= 34 @
= . Ω
= 6.5 V =
= . Ω

= 4.3 V
= ≈ . @ .

Example 7 : Series - Parallel Circuit

,

ANS : = X
+ +
1. IR1 and IR2

= + + .
= + = + = Ω

= + = + =
= . =
= Ω IR1 IR2
VR2
= = 2. VR3
35
E = = + =
= . A
Using VDR,
Using CDR
=
= + X +
+ + @ =
=
+ = +
= + + .
= 40 V
= =
= . = .