This document discusses electronic components and materials, focusing on resistors and capacitors. It provides information on: - The basic functions and types of resistors, including fixed resistors like carbon and metal film, as well as variable resistors. It describes how to read resistor color codes and calculate resistance values. - The basic principle of how capacitors store and discharge electric charge based on capacitance, voltage, and dielectric material. It gives the equations for calculating capacitance and energy storage. - Common capacitor types including mica, ceramic, electrolytic, and variable capacitors. It explains how capacitance depends on plate area, distance, and dielectric constant.

1. CHAPTER 5
ELECTRIC COMPONENTS AND MATERIALS
1. Introduction
2. Resistors
3. Capacitors
4. Inductors
5. Electric component testing

2. Electronics Components
Electronic components are basic discrete devices in any electronic system to use in electronics otherwise different associated fields. These
components are basic elements that are used to design electrical and electronic circuits. These components have a minimum of two
terminals which are used to connect to the circuit. The classification of electronic components can be done based on applications like
active, passive, and electromechanical.
In designing an electronic circuit following are taken into consideration:
 Basic electronic components: capacitors, resistors, diodes, transistors, etc.
 Power sources: Signal generators and DC power supplies.
 Measurement and analysis instruments: Cathode Ray Oscilloscope (CRO), multimeters, etc.
Passive components: cannot amplify a signal, and they do not produce mechanical motion.The most common passive electronic
components are resistors, capacitors, and inductors.
Active components can amplify a signal. The most emblematic active components are called transistors. A bipolar-junction transistor
(BJT) functions like a current-controlled current source, and a metal oxide semiconductor field-effect transistor (MOSFET)
functions like a voltage-controlled current source.
Electromechanical components convert electrical energy into mechanical motion, convert mechanical motion into electrical energy, or
facilitate electrical interconnection. The most familiar electromechanical component is the electric motor. Though the functional details of
motors vary widely, almost all of them have the same fundamental purpose: to convert electrical energy into mechanical energy in the
form of rotational motion.
Introduction

3. Bells, Alarms, and Horns.
Loudspeakers.
Microphones.
Geophones.
Hydrophones.
Telegraph Systems.
Telephones.
Vibrators.
Electromechanical components

4. Resistors
• The first use is to limit the flow of current in a circuit.
I = E / R
I = 15 V / 30 Ω
I = 0.5 A
A resistor is an electrical component that limits or regulates the flow of
electrical current in an electronic circuit. Resistors can also be used to
provide a specific voltage for an active device such as a transistor. Resistors
are commonly used to perform two functions in a circuit.

5. • The second use is to produce a voltage divider.
A to B = 1.5 V
A to C = 7.5 V
A to D = 17.5 V
B to C = 6 V
B to D = 16 V
C to D = 10 V

6. Resistor
• A component with 2 leads (connections)
• Its function in a circuit is to control the electric current flow
through the circuit
• The greater the resistance value, the less will be the
current flow
• Resistor value is measured in Ohms (Ω)
• Sometimes in a circuit the symbol for Ohms is not shown:
• 10 Ω may be written as 10R
• 0.1 Ω may be written as 0R1
• 1000 Ω may be written as 1k (1 kilo Ohms)
• The value of the resistor is read using a colour coding
scheme
Appearance
Schematic Symbol

7. The resistor color code can be used to determine the resistor’s ohmic
value and tolerance.

8. Resistor Colour Coding:
Resistance and tolerance colour bands on a resistor.

9. Examples of resistors

10. Resistance and tolerance colour code for resistors.
Resistor Colour Code
1st Band 2nd Band 3rd Band 4th Band
Band Colour
1st Digit 2nd Digit Multiplier Tolerance
Black 0 1
Brown 1 1 10
Red 2 2 100
Orange 3 3 1 000
Yellow 4 4 10 000
Green 5 5 100 000
Blue 6 6 1 000 000
Violet 7 7 10 000 000
Grey 8 8 100 000 000
White 9 9 1 000 000 000
Gold 0.1 ± 5%
Silver 0.01 ± 10%
No tolerance band ± 20%

11. Example a) Determine the nominal value and tolerance for the
resistor below.
b) What is the minimum resistance value this resistor
can actually have?
c) What is the maximum resistance value this resistor
can actually have?
Solution:
___ ___  10    ____ %
Resistor nominal value = 39105
= 3,900,000
= 3.9M.
Orange =3
3
White =9
9
Green =5
5
Silver = 10%
10
Tolerance = 10%

12. Solution: continued
 Minimum resistance value:
nominal value – nominal value * tolerance:










M
M
M
M
M
51
.
3
39
.
0
9
.
3
1
.
0
*
9
.
3
9
.
3
 Maximum resistance value:
nominal value + nominal value * tolerance:










M
M
M
M
M
29
.
4
39
.
0
9
.
3
1
.
0
*
9
.
3
9
.
3

13. Types of Resistors
Resistors are made in many forms but all belong in either of two groups:
Fixed resistors – are made of metal films, high-resistance wire or
carbon composition.
Variable resistors – have a terminal resistance that can be varied by
turning a dial, knob, screw, or anything else appropriate for the
application.

14. Fixed resistors have only one ohmic value, which cannot be changed or
adjusted. One type of fixed resistor is the composition carbon resistor.

15. Carbon resistors are very popular for most applications because
they are inexpensive and readily available in standard sizes and
wattages.
½ Watt 1 Watt 2 Watt

16. Metal film resistors are another type of fixed resistor. These resistors are
superior to carbon resistors because their ohmic value does not change
with age and they have improved tolerance.

17. Wire-wound resistors are fixed resistors that are made by winding a piece
of resistive wire around a ceramic core. These are used when a high
power rating is required.
A 10 , 10 W wire-wound resistor

18. Variable resistors can change their value over a specific range. A
potentiometer is a variable resistor with three terminals. A rheostat has
only two terminals.
A potentiometer
A rheostat.

19. Exceeding the power rating causes damage to a resistor.
The of a resistor is the specification given with a resistor that serves to tell the maximum
amount of power that the resistor can withstand.
Thus, if a resistor has a power rating of ¼ Watts, ¼ Watts is the maximum amount of
power that should be fed into the resistor.
Resistor power rating

20. Schematic symbols are used to represent various types of
fixed resistors.

21. Review:
1. Resistors are used in two main applications: as voltage dividers and to
limit the flow of current in a circuit.
2. The value of fixed resistors cannot be changed.
3. There are several types of fixed resistors such as composition carbon,
metal film, and wire-wound.
4. Carbon resistors change their resistance with age or if overheated.
5. Metal film resistors never change their value, but are more expensive than
carbon resistors.
6. The advantage of wire-wound resistors is their high power ratings.

22. Review:
7. Resistors often have bands of color to indicate their resistance value and
tolerance.
8. Resistors are produced in standard values. The number of values between 0
and 100 Ω is determined by the tolerance.
9. Variable resistors can change their value within the limit of their full value.
10. A potentiometer is a variable resistor used as a voltage divider.

23. The Capacitor
Capacitors are one of the fundamental passive components. In its most basic form, it
is composed of two plates separated by a dielectric. The ability to store charge is the
definition of capacitance.
Dielectric
Conductors

24. Dielectric
Plates
Leads
Electrons
B
A




+
+
+
+


+
+
+
+

Initially uncharged
+ 
B
A
VS
+
+
+
+
+
+
+
+
+
+
+











Fully charged
B
A
VS

+

+

+

+

+

+

+

+

+

+

+
Source removed
The charging process…
A capacitor with stored charge can act as a temporary battery.

25. Capacitance is the ratio of charge to voltage
Q
C
V

Rearranging, the amount of charge on a capacitor is determined by the size of the
capacitor (C) and the voltage (V).
Q CV

If a 22mF capacitor is connected to a 10 V source, the charge is
Capacitance
220 mC

26. An analogy:
Imagine you store rubber bands in a bottle that is
nearly full.
You could store more rubber bands (like charge
or Q) in a bigger bottle (capacitance or C) or if
you push them in with more force (voltage or V).
Thus,
Q CV


27. A capacitor stores energy in the form of an electric field that is established by
the opposite charges on the two plates. The energy of a charged capacitor is
given by the equation
2
2
1
CV
W 
where
W = the energy in joules
C = the capacitance in farads
V = the voltage in volts

28. The capacitance of a capacitor depends on three physical
characteristics.
12
8.85 10 F/m r A
C
d

  
   
 
C is directly proportional to
and the plate area.
the relative dielectric constant
C is inversely proportional to
the distance between the plates

29. 12
8.85 10 F/m r A
C
d

  
   
 
Find the capacitance of a 4.0 cm diameter sensor immersed in oil if the
plates are separated by 0.25 mm.
The plate area is
The distance between the plates is
  
3 2
12
3
4.0 1.26 10 m
8.85 10 F/m
0.25 10 m
C



 

 
  
 

 
178 pF
 
2 2 3 2
π 0.02 m 1.26 10 m
A r  
   

30. Voltage and current are always 90o out of phase. For this reason, no true
power is dissipated by a capacitor, because stored energy is returned to the
circuit.
The rate at which a capacitor stores or returns energy is called reactive
power. The unit for reactive power is the VAR (volt-ampere reactive).
Energy is stored by the capacitor during a portion of the ac cycle and
returned to the source during another portion of the cycle.
Power in a capacitor

31. Capacitor types
Mica
Mica
Foil
Foil
Mica
Foil
Foil
Mica
Foil
Mica capacitors are small with high working voltage. The working voltage is the
voltage limit that cannot be exceeded.

32. Ceramic disk
Solder
Lead wire soldered
to silver electrode
Ceramic
dielectric
Dipped phenolic coating
Silv er electrodes deposited on
top and bottom of ceramic disk
Ceramic disks are small nonpolarized capacitors They have
relatively high capacitance due to high er.

33. Electrolytic (two types)
Symbol for any electrolytic capacitor
Al electrolytic
+
_
Ta electrolytic
Electrolytic capacitors have very high capacitance but they are not as precise as
other types and tend to have more leakage current. Electrolytic types are
polarized.

34. Variable
Variable capacitors typically have small capacitance values and are
usually adjusted manually.
A solid-state device that is used as a variable capacitor is the varactor
diode; it is adjusted with an electrical signal. Symbols for the capacitor: (a) fixed;
(b) variable.

35. Capacitor labeling
Capacitors use several labeling methods. Small capacitors values are frequently
stamped on them such as .001 or .01, which have units of microfarads.
+
+
+
+
V
TT
VT
T
4
7
M
F
.022
Electrolytic capacitors have larger values, so are read as mF. The unit is usually
stamped as mF, but some older ones may be shown as MF or MMF (MMF is the same
as pf (pico-farads)).

36. A label such as 103 or 104 is read as 10x103 (10,000 pF) or 10x104 (100,000
pF) respectively. (Third digit is the multiplier.)
When values are marked as 330 or 6800, the units are picofarads.
What is the value of each capacitor? Both are 2200 pF.
222 2200

43. The ferromagnetic materials are those
substances which exhibit strong magnetism in
the same direction of the field, when a
magnetic field is applied to it.

48. Or Eddy currents are loops of electrical current induced within conductors by a
changing magnetic field in the conductor according to Faraday’s law of
induction. Eddy currents flow in closed loops within conductors, in planes
perpendicular to the magnetic field.

50. A choke, also known as an
inductor, is used to block higher-
frequency while passing direct
current (DC) and lower-
frequencies of alternating
current (AC) in an electrical
circuit.

51. VARIABLE INDUCTORS
Variable inductor products are coil products that allow the inductance to be easily
varied by changing the position of the ferrite core in a threaded structure.
The interior is covered by a metal case that is magnetically shielded, while a resin
molded structure protects the windings with a high degree of reliability.