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The following instructional plan is part of a GaDOE collection of Unit Frameworks, Performance Tasks, examples of Student Work, and Teacher Commentary. Many more GaDOE
approved instructional plans are available by using the Search Standards feature located on GeorgiaStandards.Org.
Georgia Performance Standards Framework for Physical Science – GRADE 8
Unit Three Organizer: It’s Electromagnetic
(Approximate Time: 7.5 weeks)
OVERVIEW:
By the eighth grade, students have had limited exposure to the concepts of electricity and magnetism. It is in 8th grade physical science that
most students will first be exposed to chemistry as the source of the energy that makes electricity, as well as the connected nature of
electrical charge and magnetism.
This framework is intended to expose students to the basics of charges, electrical flow through circuits, magnetism, and the integration of
electromagnetic science into technology. The students will make the connection between electricity, magnetism, and technology through
the completion of tasks designed to teach the concepts through hands-on experience. The tasks will take the students from electricity to
magnetism by constructing a simple wet cell and battery system, a simple static electric generator, an electromagnet, and culminating in the
building of two pieces of technology- a simple computer circuit, and an electrical communication device. By actually building these
devices, the students will reinforce classroom instruction and be given an opportunity to demonstrate the level of their understanding of the
concepts.
STANDARDS ADDRESSED IN THIS UNIT
Focus Standard:
S8P5. Students will recognize characteristics of gravity, electricity, and magnetism as major kinds of forces acting in nature.
b. Demonstrate the advantages and disadvantages of series and parallel circuits and how they transfer energy.
c. Investigate and explain that electric currents and magnets can exert force on each other.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 1 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
Supporting Standards:
S8P1. Students will examine the scientific view of the nature of matter.
a. Distinguish between atoms and molecules.
b. Describe the difference between pure substances (elements and compounds) and mixtures.
c. Describe the movement of particles in solids, liquids, gases, and plasmas states.
d. Distinguish between physical and chemical properties of matter as physical (i.e., density, melting point, boiling point) or chemical
(i.e., reactivity, combustibility).
S8P2. Students will be familiar with the forms and transformations of energy.
a. Explain energy transformation in terms of the Law of Conservation of Energy.
b. Explain the relationship between potential and kinetic energy.
c. Compare and contrast the different forms of energy (heat, light, electricity, mechanical motion, sound) and their characteristics.
Habits of the Mind
S8CS1. Students will explore the importance of curiosity, honesty, openness, and skepticism in science and will exhibit these traits in their
own efforts to understand how the world works.
a. Understand the importance of—and keep—honest, clear, and accurate records in science.
b. Understand that hypotheses can be valuable even if they turn out not to be completely accurate.
S8CS2. Students will use standard safety practices for all classroom laboratory and field investigations.
a. Follow correct procedures for use of scientific apparatus.
b. Demonstrate appropriate techniques in all laboratory situations.
c. Follow correct protocol for identifying and reporting safety problems and violations.
S8CS4. Students will use tools and instruments for observing, measuring, and manipulating equipment and materials in scientific
activities utilizing safe laboratory procedures.
a. Use appropriate technology to store and retrieve scientific information in topical, alphabetical, numerical, and keyword files,
and create simple files.
b. Use appropriate tools and units for measuring objects and/or substances.
c. Learn and use standard safety practices when conducting scientific investigations.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 2 of 22
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Georgia Performance Standards Framework for Physical Science – GRADE 8
S8CS5. Students will use the ideas of system, model, change, and scale in exploring scientific and technological matters.
a. Observe and explain how parts can be related to other parts in a system such as the role of simple machines in complex machines.
b. Understand that different models (such as physical replicas, pictures, and analogies) can be used to represent the same thing.
S8CS6. Students will communicate scientific ideas and activities clearly.
a. Write clear, step-by-step instructions for conducting scientific investigations, operating a piece of equipment, or following a procedure.
b. Write for scientific purposes incorporating information from a circle, bar, or line graph, data tables, diagrams, and symbols.
c. Organize scientific information in appropriate tables, charts, and graphs, and identify relationships they reveal.
S8CS6. Students will question scientific claims and arguments effectively.
a. Support statements with facts found in books, articles, and databases, and identify the sources used.
b. Identify when comparisons might not be fair because some conditions are different.
The Nature of Science
S8CS8. Students will be familiar with the characteristics of scientific knowledge and how it is achieved.
Students will apply the following to scientific concepts:
a. When similar investigations give different results, the scientific challenge is to judge whether the differences are trivial or significant,
which often requires further study. Even with similar results, scientists may wait until an investigation has been repeated many times
before accepting the results as meaningful.
b. When new experimental results are inconsistent with an existing, well-established theory, scientists may pursue further experimentation
to determine whether the results are flawed or the theory requires modification.
c. As prevailing theories are challenged by new information, scientific knowledge may change.
S8CS9. Students will understand the features of the process of scientific inquiry.
Students will apply the following to inquiry learning practices:
a. Investigations are conducted for different reasons, which include exploring new phenomena, confirming previous results, testing how
well a theory predicts, and comparing different theories. Scientific investigations usually involve collecting evidence, reasoning,
devising hypotheses, and formulating explanations to make sense of collected evidence.
b. Scientific investigations usually involve collecting evidence, reasoning, devising hypotheses, and formulating explanations to make
sense of collected evidence.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 3 of 22
Copyright 2007 © All Rights Reserved
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Georgia Performance Standards Framework for Physical Science – GRADE 8
c. Scientific experiments investigate the effect of one variable on another. All other variables are kept constant.
d. Scientists often collaborate to design research. To prevent this bias, scientists conduct independent studies of the same questions.
e. Accurate record keeping, data sharing, and replication of results are essential for maintaining an investigator’s credibility with other
scientists and society.
f. Scientists use technology and mathematics to enhance the process of scientific inquiry.
ENDURING UNDERSTANDINGS
Electricity is a general term used to refer to the presence and/or flow of electrical charges. It is usually associated with the movement or
position of those charges.
Static electricity is the attractive force between oppositely charged objects due to a buildup of negative charges. Static electricity is nonmoving charges.
A wet cell or dry cell can be used to produce electricity through a chemical reaction.
A battery is a series of electrical cells.
Insulators are poor conductors and resist charge movement while conductors are poor insulators and tend to allow charges to easily move.
Closed circuits allow current flow while open circuits do not have an unbroken path for current movement.
A series circuit contains only one path for electricity to flow, while a parallel circuit contains more than one path. Parallel circuits are an
advantage in that bulbs in parallel will still work if one of the burns out.
Magnets can induce electric current and electric current can produce a magnetic field.
Magnets can be used to make electricity when needed.
Electricity can be used to make a magnet when needed.
Electromagnets are used in electric motors to transform electrical energy to mechanical energy.
Generators convert mechanical energy to electrical energy.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 4 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
ESSENTIAL QUESTIONS:
How is electricity produced and used?
What are the advantages and disadvantages of series and parallel circuits?
How are insulators and conductors used in the movement of charges?
How is static electricity different from “regular” electricity?
How are parallel and series circuits different and how are they alike?
What are the differences between permanent magnets and electromagnets?
What are the factors that affect the strength of electromagnets?
How are electric motors related to electric generators?
In what ways are electromagnets used in modern technology?
How are electricity and magnetism used in modern technology?
CONCEPTS:
Nature of electricity and charge
Nature of electric current
Differences between direct and alternating current
Uses of conductors and insulators in circuits
Advantages and disadvantages of series and parallel circuits
Nature of magnetism
Use of electricity to generate a magnetic field
Use of magnets in creating motors and generators
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 5 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
LANGUAGE:
Battery
Cell
Circuit
Closed Circuit
Conductor
Current
Dry Cell
Electrical Charge
Electric Field
Electrical Force
Electric Motor
Electricity
Electromagnet
Generator
Induction
Insulator
Magnet
Magnetic Field
Open Circuit
Parallel Circuit
MISCONCEPTIONS
Electricity is only moving charges.
Electrical charge results from the movement of positive and negative
charges.
Electricity moves like water through a pipe.
A cell is the same as a battery.
Batteries store electricity.
Permanent Magnet
Poles
Series Circuit
Static Electricity
Switch
Technology
Transformer
Volt
Voltage
Wet Cell
PROPER CONCEPTIONS
Electricity describes the charges that result from the movement or
positions of electrical charges.
Under normal circumstances, positive charges cannot leave an atom.
Only the negative charges are able to move.
Water flows as a result of gravity. Electricity, being negatively charged,
moves away from like charged objects and towards oppositely charged
ones. Additionally, the charges require a complete path to flow.
A cell is a single unit that produces electrical current through a chemical
reaction. A battery is two or more cells connected in series or parallel
circuits.
A cell or battery may produce electricity from chemicals contained
within. Some contain chemical processes that are reversible by
recharging them.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 6 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
Wire must be coiled to produce a magnetic field.
Wire must be coiled around and iron core to produce a magnet.
Any wire carrying an electric current generates a magnetic field. Coiling
the wire increases the field to allow it to be more easily detected.
Coiled wire, or any wire carrying an electric current produces a magnetic
field. Adding an iron core strengthens and focuses the field.
EVIDENCE OF LEARNING:
Culminating Activity:
GRASPS
GOAL: You are working for a government agency that is responsible for encryption and code breaking. Your challenge is to design and build
two pieces of technology that incorporate electricity and magnetism. The first is a simple computer using electrical circuits to compute a simple
arithmetic problem and to arrive at an answer displayed by an output device. The second is to design a communication device and communicate
your findings to your team members in code.
ROLE: You are an engineer leading a team made up of your colleagues. You as the team leader will help design and build your devices and
communicate with your team members. It is up to you as a team to work well together to design and build the devices, along with your coding
system to complete the mission.
AUDIENCE: Your team members are depending upon you to solve the problem and communicate the vital information. Watching you will be
spies, such as other teams, as well as your teacher.
SCENARIO: The devices you build will be examples of technology- the use of scientific knowledge in applications that serve a purpose.
Your devices should be tested and refined and be fully functional in the end. Your team is competing with other teams (spies) to be the first to
complete the design and build of these critical devices and to complete the mission.
PRODUCT: The design of your devices will include many components of the fields of electricity and magnetism. Besides displaying your
functional devices, you will produce written reports that include detailed drawings of the parts of the devices and explanations of their
functions. You will also make your code available to your teacher, the director of your agency.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 7 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
RUBRIC FOR CULMINATING ACTIVITY
Evidence of Scientific
Understanding: Computing
Device
Exceeds Expectations
4 points
The student clearly exhibits
understanding of electrical circuits
and components in project work
and clearly explains same in
written report. There is evidence of
thorough understanding of all parts
and workings of the device.
Evidence of Scientific
Understanding:
Communication Device
Student demonstrates a thorough
understanding of the circuits and
components of the device,
including explanations of why each
part is necessary. The student also
explains the coding system and
demonstrates understanding of
same.
Organization and Analysis
Student written report clearly
shows how devices were developed
and how and why each component
is included to aid in function.
Report shows how each device
functions and includes the
descriptions of input and output to
computer and the coding system
developed for communication.
Meets Expectations
3 points
The student attempts to explain
how and in what manner electricity
flows through the device but may
not completely explain all
components in class or in writing.
The student does not exhibit
thorough understanding of how the
device computes and displays data.
Student demonstrates basic
knowledge of the communication
device, but may not thoroughly
explain how and why various
components are necessary.
Knowledge of coding system is
evident, but may not be at expert
level.
Does Not Meet Expectations
2 points
The student did not explain how
and in what manner electricity
flows through device circuits and
does not exhibit evidence of
understanding of the components
of the device.
Student does not thoroughly
explain the functions of the device
or the reasons for inclusion of the
components. Evidence does not
exist that the student understands
or has mastered the code system.
Student recording, organization and Student recording, organization and
analysis of the devices and their
analysis of the devices is not
development are included in the
complete in written report.
written report. Results of functions
are discussed minimally.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 8 of 22
Copyright 2007 © All Rights Reserved
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Georgia Performance Standards Framework for Physical Science – GRADE 8
Effort and Participation
Active student participation was
evident throughout the activity.
Student interacted with team
members and others in a respectful
and productive manner.
Student participation was evident
throughout the activity, but lacked
enthusiasm. Student interactions
were respectful and not
counterproductive.
UNIT RESOURCES
Electricity
http://atschool.eduweb.co.uk/trinity/elec2.html
http://www.kented.org.uk/ngfl/subjects/science/qca/usingelectricity.htm
http://www.energy.ca.gov/education/projects/projects-html/lightning.html
http://www.eskimo.com/~billb/amateur/coilgen.html
http://encarta.msn.com/find/Concise.asp?z=1&pg=2&ti=03AEF000
http://www.miamisci.org/af/sln/frankenstein/fruity.html
Magnetism
http://image.gsfc.nasa.gov/poetry/
http://psrc.aapt.org/
Motors/Generators
http://www.eskimo.com/~billb/amateur/coilgen.html
http://www.exploratorium.edu/snacks/stripped_down_motor.html
Technology
http://www.eecs.umich.edu/mathscience/funexperiments/agesubject/lessons/appliances.html
http://psrc.aapt.org/
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 9 of 22
Copyright 2007 © All Rights Reserved
Student did not participate or work
in each aspect of this exploration
and failed to interact with team
members in a positive and
encouraging manner.
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
Culminating Activity- Electricity and Magnetism in Technology
Standards (Content and Characteristics):
S8P5. Students will recognize characteristics of gravity, electricity, and magnetism as major kinds of forces acting in nature
S8P2. Students will be familiar with the forms and transformations of energy.
S8CS1. Students will explore the importance of curiosity, honesty, openness, and skepticism in science and will exhibit these traits in their
own efforts to understand how the world works.
S8CS2. Students will use standard safety practices for all classroom laboratory and field investigations.
S8CS4. Students will use tools and instruments for observing, measuring, and manipulating equipment and materials in scientific activities
utilizing safe laboratory procedures.
S8CS5. Students will use the ideas of system, model, change, and scale in exploring scientific and technological matters.
S8CS6. Students will communicate scientific ideas and activities clearly.
S8CS8. Students will be familiar with the characteristics of scientific knowledge and how it is achieved.
S8CS9. Students will understand the features of the process of scientific inquiry.
Enduring Understanding:
Electricity is a general term used to refer to the presence and/or flow of electrical charges. It is usually associated with the movement or
position of those charges.
Insulators are poor conductors and resist charge movement while conductors are poor insulators and tend to allow charges to easily move.
Closed circuits allow current flow while open circuits do not have an unbroken path for current movement.
A series circuit contains only one path for electricity to flow, while a parallel circuit contains more than one path. Parallel circuits are an
advantage in that bulbs in parallel will still work if one of the burns out.
Magnets can induce electric current and electric current can produce a magnetic field.
Magnets can be used to make electricity when needed.
Electricity can be used to make a magnet when needed.
Electromagnets are used in electric motors to transform electrical energy to mechanical energy.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 10 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
Essential Questions:
What are the advantages and disadvantages of series and parallel circuits?
How are insulators and conductors used in the movement of charges?
How are parallel and series circuits different and how are they alike?
What are the differences between permanent magnets and electromagnets?
What are the factors that affect the strength of electromagnets?
In what ways are electromagnets used in modern technology?
How are electricity and magnetism used in modern technology?
ADMINISTRATION PROCEDURES
Outcome /
Performance
Expectations:
Each student or team will design and create two pieces of technology incorporating electricity, circuits, and
possibly magnetism. The two devices will consist of a simple computer circuit for completing math
calculations using the digits 0 and 1. The second device will be a simple communicator using electrical
circuits and switches to light bulbs and/or ring bells to communicate via code (a telegraph) as well as a code
system by which to communicate via the device.
General Teacher
Instructions:
PART ONE- Simple Computer
Build a circuit using 2 dry cell flashlight batteries, wire, clips, switches, and bulbs as shown below.
You may want to have the students build one circuit with a switch labeled “1” and “0” to begin with, and ask
them to think of ways to use this circuit in conjunction with other circuits to do math problems. This adds an
inquiry element to the activity and will open the door to some surprising ideas from students.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 11 of 22
Copyright 2007 © All Rights Reserved
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Georgia Performance Standards Framework for Physical Science – GRADE 8
Single circuit:
Battery holder
cell
cell
On = “1”
On/off switch
Labeled “0” and “1”
Off = “0”
Flashlight
bulb
In the single circuit above, when the switch is in the “0” or off position, the bulb does not glow= 0 bulbs.
When the switch is in the “1” or on position, the bulb glows= 1 bulb.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 12 of 22
Copyright 2007 © All Rights Reserved
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Georgia Performance Standards Framework for Physical Science – GRADE 8
Battery holder
Double Circuit (computer) :
cell
cell
On = “1”
Off = “0”
On/off switch
Labeled “0” and “1”
Flashlight
bulb
On = “1”
Flashlight
bulb
On/off switch
Labeled “0” and “1”
Off = “0”
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 13 of 22
Copyright 2007 © All Rights Reserved
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Georgia Performance Standards Framework for Physical Science – GRADE 8
In the computer above, the switches are the input devices and the bulbs are the output devices. The student
enters binary data (0 or 1) via the switches. When both switches are in the “0” or off positions, there are 0
bulbs lit. When either switch is in the “1” or on position and the other is in the “0” or off position, 1 bulb is
lit. When both switches are in the “1” or on positions, 2 bulbs are lit.
Students can add more circuits and even devise ways of altering the input data. Advanced students could
potentially research binary language and build eight circuits to input eight digit binary code.
PART TWO- communicator
Students can either obtain or build a momentary switch. A momentary switch is a switch that must be held in
the on position and goes back to off when released. There are several inexpensive types of momentary
switches that can be purchased, such as a cheap doorbell button switch. The other option is to have the
students build their own.
To build a momentary switch, each student or group will use two ice cream sticks (craft sticks), bare copper
wire, a toothpick, and a rubber band. They should assemble the switch as shown below.
Wrap bare copper around two ice cream sticks as shown here:
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 14 of 22
Copyright 2007 © All Rights Reserved
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Georgia Performance Standards Framework for Physical Science – GRADE 8
Position the two sticks as shown here with extra wire trailing to the ends
Place a toothpick or other round object between the sticks and put a rubber band tightly around both sticks on
the opposite side of the toothpick as shown below. The wire wrapped around the other ends of the sticks
should only touch when the student presses on the switch and holds the two sticks together. When released,
the rubber band pulls the opposite ends together breaking the connection of the wires.
Press here to make switch connect circuit
toothpick
Rubber band
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 15 of 22
Copyright 2007 © All Rights Reserved
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Georgia Performance Standards Framework for Physical Science – GRADE 8
Using the momentary switch, students should assemble a circuit as shown below, using 2 flashlight batteries,
a battery holder, wire and clips, and flashlight bulbs and holders.
Battery holder
cell
cell
Flashlight
bulb
Momentary switch
By pressing and letting go of the switch, students cause the bulb to on and off. Holding the switch longer allows
the bulb to stay on longer. Students can design their own coding system using alternating on and off flashes and
by alternating the amount of time the bulb stays lit. Students may also begin by using actual Morse code as used
in telegraphs in the 1800’s. Once the students are familiar with coding, they may devise interesting code systems
of their own.
This system can be altered by substituting a bell or electromagnet doorbell in place of the flashlight bulb and
holder. Then it becomes an auditory communication device using alternating ringing and not ringing of the bell.
Given enough wire, the student can also build blinds so that one person cannot see the other, or move to another
part of the classroom and communicate using their devices.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 16 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
Materials Needed:
PART ONE- Simple Computer
Per student or group:
2 Flashlight bulbs
2 bulb holders
2 flashlight batteries
1 Battery holder
2 switches- preferably toggle or household switches with a clearly defined on/off setting
8-10 strands of insulated wire 6 inches in length, preferably with alligator clip connectors on each end.
(More of all the above if students are allowed to go further with this task)
PART TWO- communicator
Safety Precautions:
For the switch:
2 ice cream sticks
1 toothpick
1 rubber band
2 pieces of bare copper wire about 8 inched each
For the rest of the circuit:
2 flashlight batteries
1 battery holder
1 flashlight bulb and holder
6 strands of insulated wire 6 inches in length, preferably with alligator clip connectors on each end.
1 DC electric bell
There is almost no danger from electricity in this task. Be sure the flashlight batteries are new and in good
condition. Old batteries can leak acid and corrode metal and burn skin.
There is a potential for broken glass if the flashlight bulbs are dropped or crushed.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 17 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
Task with Student
Directions:
PART ONE- Simple Computer
Obtain the following materials
2 Flashlight bulbs
2 bulb holders
2 flashlight batteries
1 Battery holder
2 switches
8 strands of wire
Begin by building a simple circuit as shown in the diagram below.
(Be sure to label the switch with a “0” in the off position and a “1” in the on position)
Battery holder
cell
cell
On = “1”
On/off switch
Labeled “0” and “1”
Off = “0”
Flashlight
bulb
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 18 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
What happens when the switch is turned to the “0” position? ____________________
What happens when the switch is turned to the “1” position? ____________________
Think of ways to put this circuit to use and plan a way to add to it to complete math problems using this
simple computer. Design a plan for your computer on paper before you begin to build it by adding to the
above design. (Your computer should use at least two circuits)
In addition to your paper design, also create a data table that shows all switches and what your predictions
are for each combination of switch settings and what the actual results are after you build it.
PART TWO - communicator
Obtain the following materials:
For the switch:
2 ice cream sticks
1 toothpick
1 rubber band
2 pieces of bare copper wire about 8 inched each
For the rest of the circuit:
2 flashlight batteries
1 battery holder
1 flashlight bulb and holder
6 strands of insulated wire 6 inches in length, preferably with alligator clip connectors on each end.
1 DC electric bell
Electromagnetic doorbell
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 19 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
Build a momentary switch. If a switch is purchased, skip these steps.
Wrap bare copper around two ice cream sticks as shown here:
Position the two sticks as shown here with extra wire trailing to the ends
Place a toothpick or other round object between the sticks and put a rubber band tightly around both sticks on
the opposite side of the toothpick as shown below. The wire wrapped around the other ends of the sticks
should only touch when the student presses on the switch and holds the two sticks together. When released,
the rubber band pulls the opposite ends together breaking the connection of the wires.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 20 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
Press here to make switch connect circuit
toothpick
Rubber band
Using the momentary switch, students should assemble a circuit as shown below, using 2 flashlight batteries,
a battery holder, wire and clips, and flashlight bulbs and holders.
Battery holder
cell
cell
Flashlight
bulb
Momentary switch
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 21 of 22
Copyright 2007 © All Rights Reserved
One Stop Shop For Educators
Georgia Performance Standards Framework for Physical Science – GRADE 8
By pressing and letting go of the switch, students cause the bulb to on and off. Holding the switch longer
allows the bulb to stay on longer.
Using Morse Code, send messages to your lab partner and have them translate what you are sending.
Develop your own coding system on paper, and practice using the system to send messages to your partner.
Resources:
Substitute the DC bell or electromagnetic doorbell for the flashlight bulb and holder and the use the
communicator to send and receive messages.
http://mistupid.com/computers/binaryconv.htm
http://www.roubaixinteractive.com/PlayGround/Binary_Conversion/Binary_To_Text.asp
http://dept-info.labri.u-bordeaux.fr/~strandh/Teaching/AMP/Common/Strandh-Tutorial/Dir.html
http://www3.wittenberg.edu/bshelburne/Comp150/LogicGatesCircuits.html
Homework /
Extension:
Have students research binary code and other code languages.
Have students research computers and how they function.
Have students research message coding.
Georgia Department of Education
Kathy Cox, State Superintendent of Schools
Physical Science  GRADE 8  It’s Electromagnetic
July 2008  Page 22 of 22
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