Lesson Plan
Course Title: Concepts of Engineering and Technology
Session Title: Basic Electricity and Electronics: Module Two - Basic Electronics
Performance Objective:
After completing this lesson, students will demonstrate their understanding of basic electricity
and electronic fundamentals by completing the Basic Electricity and Electronics: Module Two
Quiz.
Specific Objectives:
The student will be able to:
 Recall the basic theory behind transistor operation
 Recall how basic atomic structure allows us to create controllable electronic devices
 Demonstrate a basic understanding of the binary number system
 Restate how we use transistors to create logic devices
 Apply the fundamentals of binary logic
 Use tools like the truth table to define logical operations
 Convert back and forth from decimal, binary, and hexadecimal
Preparation
TEKS Correlations:
This lesson, as published, correlates to the following TEKS. Any changes/alterations to the
activities may result in the elimination of any or all of the TEKS listed.
Concepts of Engineering and Technology:

130.362 (c)(1)(B)(C)(D)
...identify the inputs, processes, and outputs associated with technological systems;
…describe the difference between open and closed systems;
…describe how technological systems interact to achieve common goals;

130.362 (c)(6)(A)(B)(C)(D)
…identify and describe the fundamental processes needed for a project, including
design and prototype development;
…identify the chemical, mechanical, and physical properties of engineering materials;
…use problem-solving techniques to develop technological solutions;
…use consistent units for all measurements and computations;

130.362 (c)(8)(A)(B)(C)(D)(E)
…describe applications of process control and automation systems;
…describe career opportunities in process control and automation systems;
…apply design concepts to problems in process control and automation systems;
…identify fields related to process control and automation systems; and
…identify emerging issues in process control and automation systems.
Copyright © Texas Education Agency, 2012. All rights reserved.
1
Interdisciplinary Correlations:
Algebra I:

111.32 (b)(1)(A)(B)(C)(D)(E)
…describe independent and dependent quantities in functional relationships;
…gather and record data and use data sets to determine functional relationships
between quantities;
…describe functional relationships for given problem situations and write equations or
inequalities to answer questions arising from the situations;
…represent relationships among quantities using concrete models, tables, graphs,
diagrams, verbal descriptions, equations, and inequalities; and
…interpret and make decisions, predictions, and critical judgments from

111.32 (b)(3)(A)(B)
…use symbols to represent unknowns and variables; and
…look for patterns and represent generalizations algebraically.

111.32 (b)(4)(A)(B)
…find specific function values, simplify polynomial expressions, transform and solve
equations, and factor as necessary in problem situations;
…use the commutative, associative, and distributive properties to simplify algebraic
expressions; and functional relationships.
Integrated Physics and Chemistry:

112.38 (c)(3)(A)(D)(E)
…in all fields of science, analyze, evaluate, and critique scientific explanations by using
empirical evidence, logical reasoning, and experimental and observational testing,
including examining all sides of scientific evidence of those scientific explanations, so as
to encourage critical thinking by the student;
…evaluate the impact of research on scientific thought, society, and the environment;
…describe connections between physics and chemistry and future careers;

112.38 (c)(5)(C)(F)
…demonstrate that moving electric charges produce magnetic forces and moving
magnets produce electric forces;
…evaluate the transfer of electrical energy in series and parallel circuits and conductive
materials;

112.38 (c)(6)(B)(D)
…relate chemical properties of substances to the arrangement of their atoms or
molecules;
…relate the physical and chemical behavior of an element, including bonding and
classification, to its placement on the Periodic Table;
Copyright © Texas Education Agency, 2012. All rights reserved.
2
Teacher Preparation:
Read through the PowerPoint presentation and all supporting documents.
The section on basic electricity has 38 slides, and so should take a week or so to cover.
Transistor circuits require a basic understanding of DC electricity, so you may have to review
some of that material. Make sure students understand Ohm’s Law, and that voltage drops
across resistors allow you to calculate current.
References:
Goodheart-Willcox, Electricity and Electronics by Howard H. Gerrish, William E. Dugger, Jr.,
Richard M. Roberts
Cengage Learning Inc./Delmar (2008) Engineering Design and Introduction, by John R. Karsnitz,
John P. Hutchinson, Stephen O’Brien
Use Wikipedia as a resource.
Instructional Aids:
1. Module Two: Basic Electronics PPT presentation
2. Module Two: Basic Electricity and Electronics Terms and Definitions handout for each
student
3. Module Two: Basic Electricity and Electronics Problem worksheet for each student
4. Module Two: Basic Electricity and Electronics quiz for each student
5. Module Two: Basic Electricity and Electronics quiz key
Materials Needed:
Recommended but not required: examples of transistors and diodes.
Equipment Needed:
1. Computer with access to internet
2. Projector
Learner Preparation:
This lesson builds on Basic Electricity and Electronics Module 1 - Electricity.
Transistor circuits require a basic understanding of DC electricity, so you may have to review
some of that material. Make sure students understand Ohm’s Law, and that voltage drops
across resistors allow you to calculate current.
Introduction
Introduction (LSI Quadrant I):
SAY: Different materials have different physical and chemical properties. We all know about
the properties of materials like metals or wood, today we are going to learn about the properties
of a material we do not see naturally, a silicon crystal.
ASK: Does anyone know what we use silicon crystals for? (Transistors and other
Copyright © Texas Education Agency, 2012. All rights reserved.
3
semiconductor materials)
SHOW: The type of silicon crystal we use in transistor is not found naturally, but many other
forms of silicon are very common. Look at a window. The glass uses a common form of silicon
called silicon dioxide. This rock is also made of silicon in the form of silicate minerals.
SAY: Silicon is the eighth most common element found on earth, but it is rarely found in a pure
form. It is most often found in rocks like granite or sandstone, and makes up a lot of the sand
found on beaches.
ASK: Does anyone know what other element silicon is similar to? (carbon, they both have 4
valence electrons).
SHOW: The periodic table of the elements.
ASK: See how carbon and silicon fall in the same column? What is carbon used for?
SAY: Carbon is called an organic material, because it is found in all living organisms. Basic
cellular structure is made out of carbon, and so is found in trees, plants, and the human body.
The same way that carbon makes a structure that living organisms are made of, silicon can
make a physical structure that has many useful properties. Our primary interest is how we use
it to make something called a semiconductor, which are used to make the transistor that is
found in every electronic device.
Outline
Outline (LSI Quadrant II):
Instructors can use the PowerPoint presentation, slides, handouts, and note pages in
conjunction with the following outline.
MI
Outline
Notes to Instructor
I. Doping is the addition of a different type of atom
into the structure created by silicon atoms, the crystal
lattice structure.
A. Arsenic and antimony are the N type dopants
B. Gallium and indium are used as P type dopants
C. Arsenic and gallium are far more common
D. Doping creates the conductivity in a
semiconductor
E. More doping means more impurity atoms, and
gives more conductivity
Begin PowerPoint
presentation Module
Two – Basic
Electronics. Because
this material is new,
take your time and
cover the material
slowly. Try to allow
time for students to
digest the information.
II. The P and N material are created side by side
(not put together) in an photo lithographic process.
http://www.appliedmaterials.com/htmat/animated.html
III. A PN junction is a Diode, which conducts with only
one polarity of voltage applied
A. Positive to the P
B. Negative to the N
C. Used in a rectifier to convert AC voltage to DC
voltage
Continue PowerPoint
presentation.
Copyright © Texas Education Agency, 2012. All rights reserved.
4
.
D. A transistor has 2 junctions and 3 layers, but still
only conducts in one direction
E. A transistor can give what looks like AC out by
varying conduction, with the DC bias voltage
filtered out using a capacitor
IV. You can replace a transistor with a switch and the
circuit works the same way.
A. An “on” transistor has low resistance and a small
voltage drop across it (collector to emitter), about
1 volt
B. An “off” transistor has high resistance (infinite),
and all the voltage is dropped across it with no
current
C. The base to emitter junction always has about a
.7 (seven tenths) volt drop across it when
forward biased
AND gates and OR
gates are generally the
first logic devices
introduced using a
traditional text, we
introduce the inverter
first because it is one
of the simplest
transistor circuits.
V. The definition of logic is that exactly the same thing
happens with a specified set of inputs.
A. Logic follows specific rules
B. The rules are defined by a truth table
C. Some of the common rules are the AND, OR,
and invert functions
D. These simple functions (gates) are placed
together in circuits that can perform much more
complex functions
E. Important additional logic functions not
discussed in the presentation include
DeMorgans Theorem and the Karnaugh Map.
Distribute and go over
the Terms and
Definition handout.
Some of the
descriptions need
more detail than given
in the presentation,
and the handout tries
to describe things in
simple terms that
students can
understand.
VI. The adder and the memory decoder are two of the
most important circuit functions in a computer. They
are also simple and easy to understand.
A. Most things in a computer perform very simple
operations.
B. Millions of simple operations performed very
quickly provide the power and the versatility of a
computer.
Continue PowerPoint
presentation.
VII. The binary number system and the decimal
number system are very similar.
Continue PowerPoint
presentation.
Copyright © Texas Education Agency, 2012. All rights reserved.
5
A. Each digit has a value that is a multiple of the
previous digit (2 in binary, 10 in decimal)
B. A carry works the same way in both number
systems
C. Hexadecimal is also the same, but with 16
values can be confusing
D. The letter a, b, c, d, e, f are used exactly like
single digit numbers with values 10, 11, 12, 13,
14, 15
Verbal
Linguistic
Logical
Mathematical
Visual
Spatial
Musical
Rhythmic
Bodily
Kinesthetic
Intrapersonal
Interpersonal
Naturalist
Existentialist
Application
Guided Practice (LSI Quadrant III):
Most of the guided practice will come from having you and the students work problems together.
The first problems will involve simple transistor circuits. You can calculate voltage drops across
resistors until you get to transistor saturation, where all of the power supply voltage is dropped
across the collector resistor. You will have many more problems involving decimal to binary,
binary to decimal, and hexadecimal conversions.
Independent Practice (LSI Quadrant III):
Students will work on the Problems worksheet. The teacher should go over problems with the
students first, but then have the students work problems independently. You should be able to
find or make up any number of additional problems for them to work.
Summary
Review (LSI Quadrants I and IV):
Question: What are the two types of doping?
Answer: N and P
Question: How do we created N and P type materials?
Answer: For N, dope with a tetravalent atom (an atom with 5 electrons in the outer shell).
For P, dope with a trivalent atom (an atom with only 3 electrons in the outer shell).
Question: What are the two characteristic of the depletion region?
Answer: A charged region with no current carrying particles.
Question: What are the two characteristics that describe the base region of a transistor?
Copyright © Texas Education Agency, 2012. All rights reserved.
6
Answer: Thin and lightly doped.
Question: Which junction is forward biased in a working transistor? Which junction is normally
reverse biased?
Answer: The base emitter junction is forward biased, the base collector junction is reverse
biased.
Question: What is the truth table for an inverter? An AND gate? An OR gate?
Answer: Given in the presentation.
Evaluation
Informal Assessment (LSI Quadrant III):
Students should write out definitions, and complete Basic Electricity and Electronics - Module
Two: Basic Electronics Problem Worksheet.
Formal Assessment (LSI Quadrant III, IV):
Basic Electricity and Electronics Module Two: Basic Electronics Quiz.
Extension
Extension/Enrichment (LSI Quadrant IV):
Have students figure out the truth table for a binary subtractor. Zero minus one involves the
concept of a borrow, which must come from the next higher bit value. Working from the truth
table for a subtractor, students can make up a circuit which performs the subtraction function
The two bit adder can only be used for the least significant bit in an addition. A three bit adder
is far more useful, but more complicated. Have students figure out the truth table for a 3 bit
adder (3 inputs, 2 outputs), then see if they can figure out how to build a circuit that performs the
function. This will show students that many logic gates are needed to perform even a simple
function, and will also show that we need more than the three simple gates introduced so far.
Copyright © Texas Education Agency, 2012. All rights reserved.
7
Basic Electricity and Electronics
Module Two – Terms and Definitions
1. Electrons are particles that orbit the nucleus of an atom.
2. Orbits are grouped into energy bands known as shells.
3. Valence electrons contribute to chemical reactions and bonding.
4. Doping is the process of adding impurities to pure semiconductor material. The
base region in a transistor is thin and heavily doped.
5. Recombination is when an electron falls into a hole.
6. We create an N-type semiconductor by adding pentavalent atoms.
7. The term bias means a DC voltage applied to control the operation of a device.
8. Holes are the space in a covalent bond where a shared electron should be. The
majority carriers in P-type semiconductor material are holes.
9. Cathode is the N region of a diode.
10. The atom becomes an ion when it gains or loses a valence electron.
11. Covalent bonds are where electrons are shared between two atoms.
Atoms within a crystal are held together by covalent bonds.
12. There are two PN junctions in a Bipolar Junction Transistor.
13. The base-emitter junction is the PN junction that is forward biased in
an operating transistor circuit.
Copyright © Texas Education Agency, 2012. All rights reserved.
8
14. The Truth Table is used to illustrate the output for all possible
combinations of inputs.
15. A Boolean equation can be used to mathematically illustrate the
functional operation of a logic gate.
16. A binary digit is called a bit.
17. It takes eight (8) binary bits to represent a 2 digit hexadecimal number.
18. ASCII is the code used to represent letters, symbols, and numbers.
19. The decimal number system has ten possible values.
20. Period is the length of time from one pulse to another.
21. Transistor is the device that is used most often in a TTL circuit.
22. Depletion layer is a charged region depleted of both types of current
carrying particles (electrons and holes).
23. The phrase “totem pole” in a circuit means two transistors in a series
array, the emitter of the top connected to the collector of the bottom.
24. Digital logic is where a circuit or a system follows a defined set of rules. You
get the exact same output based on a defined input every time.
25. Explain the difference between digital and analog: Digital has steps
represented by whole numbers converted to binary. Analog has infinite
values represented by a smooth and continuous curve.
26. Describe an ohmmeter test of a diode: Take two tests with opposite
meter polarity across the diode. One polarity should read low resistance (or .7V),
the other polarity should read infinite resistance. Read once; reverse the leads;
read again.
Copyright © Texas Education Agency, 2012. All rights reserved.
9
Basic Electricity and Electronics
Module Two - Problem Worksheet
1. Convert the decimal number 131 to binary:
2. Convert the binary number 11010101 to decimal:
3. Convert the binary number 11001001 to hexadecimal:
4. Convert the decimal number 758 to hexadecimal:
5. Convert the hexadecimal number B6A to decimal:
6. Give the truth table for an inverter:
7. Give the truth table for an OR gate:
Copyright © Texas Education Agency, 2012. All rights reserved.
10
8. Give the truth table for an AND gate:
9. Give the truth table for two input (A and B) addition:
10. Draw the schematic symbol on an NPN transistor, label the leads, and
indicate the proper polarities for operation:
11. Draw the schematic symbols for the inverter, the OR gate, and the AND
gate:
Copyright © Texas Education Agency, 2012. All rights reserved.
11
Basic Electricity and Electronics
Module Two - Problem Worksheet Key
1. Convert the decimal number 131 to binary:
010000011
2. Convert the binary number 11010101 to decimal:
213
3. Convert the binary number 11001001 to hexadecimal:
C9
4. Convert the decimal number 758 to hexadecimal:
Convert to binary: 001011110110
Group 4 bits each: 0010 1111 0110
=
2F6h
5. Convert the hexadecimal number B6A to decimal:
Convert to binary: 1100 0110 1010
= 2048+1024+64+32+8+2 = 3178
6. Give the truth table for an inverter:
A
X
0
1
1
0
7. Give the truth table for an OR gate:
A
B
Q
0
0
1
1
0
1
0
1
0
1
1
1
Copyright © Texas Education Agency, 2012. All rights reserved.
12
8. Give the truth table for an AND gate:
A
B
Q
0
0
1
1
0
1
0
1
0
0
0
1
9. Give the truth table for two input (A and B) addition:
A
B
Σ
Co
0
0
1
1
0
1
0
1
0
1
1
0
0
0
0
1
10. Draw the schematic symbol on an NPN transistor, label the leads, and
indicate the proper polarities for operation:
Collector (+) (large
pos)
Base
(+)
(smal
l pos)
Emitter (neg, or
ground)
11. Draw the schematic symbols for the inverter, the OR gate, and the AND
gate:
Copyright © Texas Education Agency, 2012. All rights reserved.
13
Basic Electricity and Electronics
Module Two Quiz
1. What type of particle orbits the nucleus of an atom?
a.
b.
c.
d.
Proton
Neutron
Electron
Hole
2. Orbits are grouped into energy bands known as _______?
a.
b.
c.
d.
Electrons
Atoms
Ions
Shells
3. Which electrons contribute to chemical reactions and bonding?
a.
b.
c.
d.
Valence electrons
Free electrons
Semiconductor electrons
Intrinsic electrons
4. The process of adding impurities to pure semiconductor material is called
_________?
a.
b.
c.
d.
Doping
Hole current
Recombination
Conduction
5. Recombination is when :
a.
b.
c.
d.
A crystal is formed
A valence electron becomes a conduction electron
A positive and a negative ion bond together
An electron falls into a hole
6. We create an N-type semiconductor by adding ___________?
a.
b.
c.
d.
Trivalent atoms
P-type atoms
Pentavalent atoms
Holes
Copyright © Texas Education Agency, 2012. All rights reserved.
14
7. The term “bias” means:
a.
b.
c.
d.
The ratio of majority carriers to minority carriers
The amount of current through the pn junction
A DC voltage applied to control the operation of a device
The teacher’s grading scale
8. The majority carriers in P-type semiconductor material are ________?
a.
b.
c.
d.
Electrons
Holes
Silicon
Crystals
9. The N region of a diode is called the ________?
a.
b.
c.
d.
Cathode
Anode
Diode
Depletion region
10. When an atom gains or loses a valence electron, the atom becomes ________?
a.
b.
c.
d.
Covalent
Neutral
A crystal
An ion
11. Atoms within a crystal are held together by
a.
b.
c.
d.
Atomic glue
Subatomic particles
Covalent bonds
Forces of attraction
12. How many PN junctions are there in a Bipolar Junction Transistor?
a:
b:
c:
d:
One
Two
Three
Four
Copyright © Texas Education Agency, 2012. All rights reserved.
15
13. Which PN junction is forward biased in an operating transistor circuit?
a.
b.
c.
d.
The
The
The
The
base-collector junction
collector-emitter junction
base-emitter junction
gate-collector junction
14. The base region in a transistor is:
a.
b.
c.
d.
Thin and lightly doped
Thin and heavily doped
Thick and lightly doped
Thick and heavily doped
15. Which of the following is used to illustrate the output for all possible
combinations of inputs?
a.
b.
c.
d.
NAND gate
Boolean equation
Timing diagram
Truth table
16. What can be used to mathematically illustrate the functional operation of a
logic gate?
a.
b.
c.
d.
Logic probe
Boolean equation
Truth table
Timing diagram
17. A binary digit is called a:
a.
b.
c.
d.
Bit
Byte
Word
Number system
18. How many binary bits does it take to represent a 2-digit hexadecimal number:
a.
b.
c.
d.
2
4
8
16
Copyright © Texas Education Agency, 2012. All rights reserved.
16
19. What code is used to represent letters, symbols, and numbers?
a.
b.
c.
d.
Binary Coded Decimal
Hexadecimal
ASCII
Digital
20. Which number system has ten possible values?
a.
b.
c.
d.
ASCII
Decimal
Binary
Hexadecimal
21. The length of time from one pulse to another is called the:
a.
b.
c.
d.
Frequency
Period
Timing diagram
Hertz
22. Which of the following devices is used most often in a TTL circuit?
a.
b.
c.
d.
Diode
Transistor
Relay
CMOS
23. Convert the decimal number 131 to binary.
24. Convert the binary number 11010101 to decimal.
25. Convert the binary number 11001001 to hexadecimal.
Copyright © Texas Education Agency, 2012. All rights reserved.
17
26. Convert the decimal number 758 to hexadecimal.
27. Convert the hexadecimal number B6A to decimal.
28. Explain the difference between digital and analog.
29. Give the truth table for an inverter.
30. Give the truth table for an OR gate.
Copyright © Texas Education Agency, 2012. All rights reserved.
18
31. Give the truth table for an AND gate.
32. Give the truth table for two input (A and B) addition.
33. Describe an ohmmeter test of a diode.
34. Draw the schematic symbol on an NPN transistor, label the leads, and indicate
the proper polarities for operation.
Copyright © Texas Education Agency, 2012. All rights reserved.
19
35. Draw the schematic symbols for the inverter, the OR gate, and the AND gate.
36. What is a covalent bond?
37. Describe a hole.
38. Describe the characteristics of the depletion layer.
39. What does the phrase “totem pole” in a circuit mean?
40. What is the definition of digital logic?
Copyright © Texas Education Agency, 2012. All rights reserved.
20
Basic Electricity and Electronics
Module Two Quiz Key
1. What type of particle orbits the nucleus of an atom?
e.
f.
g.
h.
Proton
Neutron
Electron
Hole
2. Orbits are grouped into energy bands known as _______?
e.
f.
g.
h.
Electrons
Atoms
Ions
Shells
3. Which electrons contribute to chemical reactions and bonding?
e.
f.
g.
h.
Valence electrons
Free electrons
Semiconductor electrons
Intrinsic electrons
4. The process of adding impurities to pure semiconductor material is called
_________?
e.
f.
g.
h.
Doping
Hole current
Recombination
Conduction
5. Recombination is when :
e.
f.
g.
h.
A crystal is formed
A valence electron becomes a conduction electron
A positive and a negative ion bond together
An electron falls into a hole
6. We create an N-type semiconductor by adding ___________?
e.
f.
g.
h.
Trivalent atoms
P-type atoms
Pentavalent atoms
Holes
Copyright © Texas Education Agency, 2012. All rights reserved.
21
7. The term “bias” means:
e.
f.
g.
h.
The ratio of majority carriers to minority carriers
The amount of current through the pn junction
A DC voltage applied to control the operation of a device
The teacher’s grading scale
8. The majority carriers in P-type semiconductor material are ________?
e.
f.
g.
h.
Electrons
Holes
Silicon
Crystals
9. The N region of a diode is called the ________?
e.
f.
g.
h.
Cathode
Anode
Diode
Depletion region
10. When an atom gains or loses a valence electron, the atom becomes ________?
e.
f.
g.
h.
Covalent
Neutral
A crystal
An ion
11. Atoms within a crystal are held together by
e.
f.
g.
h.
Atomic glue
Subatomic particles
Covalent bonds
Forces of attraction
12. How many PN junctions are there in a Bipolar Junction Transistor?
a:
b:
c:
d:
One
Two
Three
Four
Copyright © Texas Education Agency, 2012. All rights reserved.
22
13. Which PN junction is forward biased in an operating transistor circuit?
e.
f.
g.
h.
The base-collector junction
The collector-emitter junction
The base-emitter junction
The gate-collector junction
14. The base region in a transistor is:
e.
f.
g.
h.
Thin and lightly doped
Thin and heavily doped
Thick and lightly doped
Thick and heavily doped
15. Which of the following is used to illustrate the output for all possible
combinations of inputs?
e.
f.
g.
h.
NAND gate
Boolean equation
Timing diagram
Truth table
16. What can be used to mathematically illustrate the functional operation of a
logic gate?
e.
f.
g.
h.
Logic probe
Boolean equation
Truth table
Timing diagram
17. A binary digit is called a:
e.
f.
g.
h.
Bit
Byte
Word
Number system
18. How many binary bits does it take to represent a 2-digit hexadecimal number:
e.
f.
g.
h.
2
4
8
16
Copyright © Texas Education Agency, 2012. All rights reserved.
23
19. What code is used to represent letters, symbols, and numbers?
e.
f.
g.
h.
Binary Coded Decimal
Hexadecimal
ASCII
Digital
20. Which number system has ten possible values?
e.
f.
g.
h.
ASCII
Decimal
Binary
Hexadecimal
21. The length of time from one pulse to another is called the:
e.
f.
g.
h.
Frequency
Period
Timing diagram
Hertz
22. Which of the following devices is used most often in a TTL circuit?
e.
f.
g.
h.
Diode
Transistor
Relay
CMOS
23. Convert the decimal number 131 to binary.
010000011
24. Convert the binary number 11010101 to decimal.
213
Copyright © Texas Education Agency, 2012. All rights reserved.
24
25. Convert the binary number 11001001 to hexadecimal.
C9
26. Convert the decimal number 758 to hexadecimal.
Convert to binary: 001011110110
Group 4 bits each: 0010 1111 0110
=
2F6h
27. Convert the hexadecimal number B6A to decimal.
Convert to binary: 1100 0110 1010
= 2048+1024+64+32+8+2 = 3178
28. Explain the difference between digital and analog.
Digital has steps represented by whole numbers converted to binary.
Analog has infinite values represented by a smooth and continuous
Curve.
29. Give the truth table for an inverter.
A
X
0
1
1
0
Copyright © Texas Education Agency, 2012. All rights reserved.
25
30. Give the truth table for an OR gate.
A
B
Q
0
0
1
1
0
1
0
1
0
1
1
1
31. Give the truth table for an AND gate.
A
B
Q
0
0
1
1
0
1
0
1
0
0
0
1
32. Give the truth table for two input (A and B) addition.
A
B
Σ
Co
0
0
1
1
0
1
0
1
0
1
1
0
0
0
0
1
Copyright © Texas Education Agency, 2012. All rights reserved.
26
33. Describe an ohmmeter test of a diode.
Take two tests with opposite meter polarity across the diode. One
polarity should read low resistance (or .7V), the other polarity should
read infinite resistance. Read once, reverse the leads, read again.
34. Draw the schematic symbol on an NPN transistor, label the leads, and indicate
the proper polarities for operation.
Collectror (+) (large
pos)
Base
(+)
(smal
l pos)
Emitter (neg, or
ground)
35. Draw the schematic symbols for the inverter, the OR gate, and the AND gate.
36. What is a covalent bond?
Where electrons are shared between two atoms.
Copyright © Texas Education Agency, 2012. All rights reserved.
27
37. Describe a hole.
A space in a covalent bond where a shared electron should be.
38. Describe the characteristics of the depletion layer.
A charged region depleted of both types of current carrying particles
(electrons and holes).
39. What does the phrase “totem pole” in a circuit mean?
Two transistors in a series array, the emitter of the top connected to
the collector of the bottom.
40. What is the definition of digital logic?
Where a circuit or a system follows a defined set of rules. You get the
exact same output based on a defined input every time.
Copyright © Texas Education Agency, 2012. All rights reserved.
28