Electrical Energy - Rochester Institute of Technology

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THE TEAK PROJECT: TRAVELING ENGINEERING ACTIVITY KITS Electrical Energy
Partial support for this project was provided by the National Science Foundation's Course, Curriculum, and
Laboratory Improvement (CCLI) program under Award No. 0737462. Any opinions, findings, and conclusions or
recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the
National Science Foundation.
Partial support for this project was provided by the American Society for Heating, Refrigeration, and AirConditioning Engineering (ASHRAE) through a Senior Projects grant. Any opinions findings and conclusions or
recommendations expressed here are those of the author(s) and do not necessarily reflect the views of ASHRAE
The TEAK Project
Rochester Institute of Technology
TEAK
Electrical Energy Lesson Plan
Page 2
ACTIVITY OVERVIEW
Electrical Energy Kit Overview
Students completing this kit will build several types of electrical circuits to learn about electrical energy. They
will explore the differences between series and parallel circuits, make hypotheses about circuit performance, and
take measurements to test their hypotheses.
Activity
Time
Conductor and Insulator
Word Sort
5 min
Circuit Building Activity
30 min
Lesson Extender: Capacitor
Activity
25 min
Description
This activity allows the students to differentiate conductors and
insulators while acknowledging similarities and differences.
This activity allows the students to recreate several different types
of circuits and analyze the effects of the circuit structure on voltage
and current.
Using several different capacitor sizes the students are asked to
determine the effects of an LED on a capacitor. The discharge time
for each capacitor bundle is then used to demonstrate how
capacitors use the energy that has been stored inside of them.
Learning Objectives
By the end of this lesson, students should be able to…
• Understand concepts related to electrical energy, voltage and current
• Understand series and parallel circuits
• Explain the functionality of a resistor
• Understand concepts related to electron flow, atoms and matter
NYS Learning Standards
Standard 4: Energy exists in many forms, and when these forms change energy is conserved.
• Describe a variety of forms of energy (e.g., heat, chemical, light) and the changes that occur in objects
when they interact with those forms of energy.
• Observe the way one form of energy can be transformed into another form of energy present in common
situations (e.g., mechanical to heat energy, mechanical to electrical energy, chemical to heat energy).
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Rochester Institute of Technology
TEAK
Electrical Energy Lesson Plan
Page 3
TABLE OF CONTENTS Instructor Preparation Guide.................................................................................................................................. 4 Pointers for Electrical Energy Kit .......................................................................................................................... 4 Electrical Energy Activity Introduction ................................................................................................................. 6 Background Information......................................................................................................................................... 6 Electricity Group Discussion .................................................................................................................................. 6 Procedure ................................................................................................................................................................ 8 Follow up Discussion ............................................................................................................................................. 8 Learning Objectives ................................................................................................................................................ 9 Materials for Each Group ....................................................................................................................................... 9 Safety Precautions .................................................................................................................................................. 9 Procedure ................................................................................................................................................................ 9 Expected Results................................................................................................................................................... 10 Concluding Discussion ......................................................................................................................................... 10 Electrical Energy – Lesson Extender .................................................................................................................... 11 Capacitors Group Discussion ............................................................................................................................... 11 Learning Objectives .............................................................................................................................................. 13 Materials for Each Group ..................................................................................................................................... 13 Procedure .............................................................................................................................................................. 13 Expected Results................................................................................................................................................... 14 Concluding Discussion ......................................................................................................................................... 14 Trouble-Shooting Guide......................................................................................................................................... 15 Replacement of Parts ............................................................................................................................................ 15 Use of Multi-meters .............................................................................................................................................. 15 Current Activity Handout...................................................................................................................................... 16 Parallel Circuit & Measuring Current Handout ................................................................................................. 17 Capacitor Handout ................................................................................................................................................. 18 Image Sources ......................................................................................................................................................... 19 Extended Resources ................................................................................................................................................ 19 Revisions .................................................................................................................................................................. 19 Signifies Activity
Signifies Group Discussion
The TEAK Project
Rochester Institute of Technology
TEAK
Electrical Energy Lesson Plan
Page 4
INSTRUCTOR PREPARATION GUIDE
Pointers for Electrical Energy Kit
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Make sure you let the students know why they are sorting insulators vs. conductors.
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If possible, use the slideshow to explain the terms. If you can’t use the slideshow, make sure you have
another kind of visual - draw on the board, bring in printed sheets of parallel/series circuits etc.
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Try to keep everyone on the same challenge…this way you can help them set up the multi-meters and
make sure they are measuring the correct thing.
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Voltage Setting
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Current Setting
Dial
Dial
Red Probe
Red Probe
Black Probe
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It might be helpful to label the light bulbs on the physical boards
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When measuring the current, the light bulbs will dim
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Electrical Energy Kit Lesson Plan
Page 5
Electrical Energy
DURATION
60 Minutes
CONCEPTS
Electrical Energy
Atoms and Matter
Electron Flow
Series and Parallel Circuits
Voltage and Current
Resistors
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Electrical Energy Kit Lesson Plan
Page 6
ELECTRICAL ENERGY ACTIVITY INTRODUCTION
Background Information
Electricity is a form of energy produced by the movement of electrons. The movement of electrons induces an
electric current from which power can be generated. Current can be sent through wires to produce light, supply
power, or generate heat.
Electricity Group Discussion
(Pose the following questions to the group and let the discussion flow naturally…try to give positive
feedback to each child that contributes to the conversation.)
Q: What do you have at home or school that runs on electricity?
• Toaster
• Microwave
• New Ovens with coils
• Computers
Just to name a few…
Q: Where does electrical energy come from?
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Power plants (coal, nuclear)
Batteries
Portable generators
Q: Do you know any alternative ways of producing electricity that are being developed today?
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Solar
Hydro
Wind
Fuel Cell
Geo-thermal
Q: What kind of job do you think a person would have if they develop new ways of producing energy?
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Engineers and scientists
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TEAK
Electrical Energy Kit Lesson Plan
Page 7
Electrical Circuit
(Draw this circuit on the board to explain positive and negative connections and how they complete a circuit. Also
explain the terms following the diagrams using the diagrams when necessary. Continue with discussion)
Series Circuit Parallel Circuit Terms
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Electron: the negatively charged particle of an atom that is free to move around
Electricity: the form of energy created by movement of electrons
Conductor: a material that allows electricity to move through it easily
Insulator: a material that does not allow electricity to pass through it easily
Source: something that provides the circuit with power i.e. batteries
Resistor: something that dissipates the energy i.e. light bulbs
Voltage: the measure of the force pushing the electrons through a circuit
o Example: if a tank of water were suspended one meter above the ground with a one-centimeter
pipe coming out of the bottom, the water pressure would be similar to the force of a shower. If the
same water tank were suspended 10 meters above the ground, the force of the water would be
much greater, possibly enough to hurt you. (If you jumped from a one-meter diving board, the
force when you hit the water would not be too great. If you jumped from a 10-meter board, the
force would be much greater).
Current: The flow of electrons
o Example: if a water tank has a one centimeter diameter pipe coming out of it, less water can flow
through it compared to the same tank with a 10 centimeter diameter pipe.
Series: In order for the light bulbs to be in series, they have to be connected so the current only has one
way to go. This makes the current the same through each light bulb.
Parallel: In order for the light bulbs or resistors to be in parallel, the positive sides need to be connected
together and the negative sides need to be connected together. This makes the voltage across each resistor
the same.
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Electrical Energy Kit Lesson Plan
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Q: How do you know if the circuit is closed?
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The circuit is closed if current is flowing through all of the components. Think of Christmas lights. If
one bulb goes out the circuit is no longer closed and the entire string goes out, but if all of the bulbs are
on and working properly then current is flowing through the circuit. New style light bulbs have what is
called a third strand cord so that there is always a closed circuit and will still light up even if one bulb
goes out. Third strand cords have three wires instead of two in which the third wire connects all lights to
keep the circuit flowing.
Current Flow
• Everything on the planet wants to be in balance. Because there is a positive side to the source and a
negative side, the electrons from the negative end of the source want to go to the positive end of the
source. This movement of electrons is electrical energy!
Q: Do you think we can build a circuit with string, pencils and some gum?
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An electrical circuit can only be made with objects or materials that electrical current can flow through conductors.
Conductor and Insulator Word Sort Activity –5 Minutes Procedure
Allow groups to sort the given words into two groups to differentiate conductors vs. insulators
Conductors:
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Insulators:
Silver
Copper
Gold
Aluminum
Iron
Steel
Brass
Bronze
Mercury
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Glass
Rubber
Asphalt
Porcelain
Ceramic
Quartz
Plastic
Air
Diamond
Follow up Discussion
Q: Do you see something in common about all the conductors?
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They are all metals
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Electrical Energy Kit Lesson Plan
Page 9
Circuit Activity – 45 Minutes Learning Objectives
By the end of this exercise, students should be able to…
• Build and understand a basic circuit
• Use a multi-meter to measure voltage
Materials for Each Group
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1 Circuit Board
Alligator Clips
1 Multi-meter
3 Light bulbs
Safety Precautions
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Make sure ALL light bulbs are in place before students start constructing circuits.
Procedure
1. Explain the kits before handing them out:
• On the circuit board, the red wire is the positive end of the battery and the black wire is the negative end
of the battery.
• The alligator clips are all the same connecting wire; however the color can be used to organize positive
and negative connections.
• Explain to the students that connecting the two ends of the battery directly will cause the circuit boards to
short circuit (fail).
2. Now, hand out the kits. Instruct the students to take out only the circuit board, three light bulbs, and the
alligator clips. Put everything else back in the box and place it on the floor.
3. Make sure that the students have ALL the light bulbs in place before they start connecting the battery.
4. Pass out the activity handout.
5. Instruct each of the groups to follow the instructions on the handout.
6. When they have finished, discuss their results with them.
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Electrical Energy Kit Lesson Plan
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Expected Results
The students should observe that the current is lowered as more light bulbs are added to the circuit.
Concluding Discussion
Q: What did you notice about the voltage in the series circuits? What about the brightness of the bulbs?
Q: What did you notice about the current in the parallel circuits? What about the brightness of the bulbs?
Q: How did the brightness of the bulbs in the series setup compare to the brightness of the bulbs in the
parallel setup?
Q: Why would you want to use a circuit with components in series/parallel?
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In parallel all of the components have the same voltage
In series all of the components have the same current
Q: Did anyone know something was wrong at any given point? What did you change? How did you know
to change that?
Q: What kind of materials in your home could you use to create another electrical circuit?
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TEAK
Electrical Energy Kit Lesson Plan
Page 11
ELECTRICAL ENERGY – LESSON EXTENDER
Capacitors Group Discussion
(Pose the following questions to the group and let the discussion flow naturally…try to give positive
feedback to each child that contributes to the conversation.)
Q: How does a battery work?
A battery uses a chemical reaction to generate electrical energy. However because a battery creates power
through a chemical process the speed at which it creates energy is limited.
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Q: How can power be stored?
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Power can be stored either in a rechargeable battery or in a capacitor.
Q: What is a capacitor?
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A capacitor is the part of a circuit used to store charge (electrons) for a small amount of time, usually
made of two metal plates separated by insulating material.
A capacitor is similar to a battery. Capacitors and batteries both store energy.
Here are a few differences between batteries and capacitors:
Batteries:
• Make electrical energy
• Give off a small amount of electrical energy at a slow, constant rate
• Not always rechargeable
Capacitors:
• Store electrical energy
• Give off large amount of electrical energy quickly
• Can be charged and discharged over and over
o Think about when you scuff your feet on the floor. This builds up a charge and when you touch a
doorknob the charge releases quickly. You can do this over and over.
In an electronic circuit diagram, a capacitor is shown like this:
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Electrical Energy Kit Lesson Plan
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When you connect a capacitor to a battery, here's what happens:
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The capacitor end that is attached to the negative terminal of the battery accepts electrons.
The capacitor end that is attached to the positive battery terminal loses electrons to the battery.
Because one side of the capacitor now has more than the other there is a difference. This difference is
called voltage.
Think of the capacitor as a dam. And the battery as a river. More and more water builds up on one side,
and on the other side there is no more water. The dam can only hold as much water as the river has. And
once the dam is open the water flows through on its own.
Once charged the capacitor has the same voltage as the power source that was charging it.
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Rochester Institute of Technology
TEAK
Electrical Energy Kit Lesson Plan
Page 13
Capacitor Activity – 30 Minutes Learning Objectives
By the end of this exercise, students should be able to…
• Understand the difference between capacitors and batteries
• Practice making circuits
• Learn about another common item in circuits, besides batteries and light bulbs.
Materials for Each Group
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1 Circuit Board
Alligator Clips
3 Capacitor Bundles
1 Resistor
1 clear LED light
Procedure
1. Instruct the students to take out only the circuit board, capacitors, resistor, LED light, and the alligator
clips. Put everything else back in the box and place it on the floor.
2. Pass out the activity handout.
3. Instruct each of the groups to follow the instructions on the handout.
4. When they have finished, discuss their results with them.
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Electrical Energy Kit Lesson Plan
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Expected Results
The students should observe that the larger the capacitor bundles are, the longer the LED light will stay lit.
Concluding Discussion
Q: Which capacitor allowed the LED to stay lit the longest? Why did that happen?
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The biggest capacitor - it can store more electrical energy and use that energy over a longer period of
time.
Q: What did you notice about the current in the parallel circuits? What about the brightness of the bulbs?
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Capacitors: For larger power/short duration applications
Batteries: For slow consistent discharge
Q: Think of your parents’ car. Many things are run off electricity in a car. If you thought about the turn
signals versus the headlights, which one would you need a capacitor for?
• Turn signals – short flashes of light that are repeated, large amount of energy needed to make the light
turn on
Q: Can you think of anything that would use a capacitor?
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Surround Sound Speaker connections
Turn on/off switches
Flashes on cameras
Computers (storing information)
Defibrillator – the machine doctors use to stimulate a stopped heart
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Electrical Energy Kit Lesson Plan
Page 15
TROUBLE-SHOOTING GUIDE
Replacement of Parts
Many circuit components will deteriorate over time, which may lead to failures. Specific problems may include:
battery packs shorting, plastic melting, LEDs no longer working due to excess current being applied, inability of
capacitors to hold electricity due to incorrect charging, and so on. If any of these occur, replacement parts may be
found in the plastic bag.
Use of Multi-meters
For proper operation, make sure of the following:
• Leads are plugged in to the correct ports
• The knob is turned to “DCV 20”
• The pointed ends are being pressed onto a positive and negative end
• A 9-volt battery (inside the multi-meter) may need to be replaced
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Electrical Energy Kit Lesson Plan
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CURRENT ACTIVITY HANDOUT
Before using any alligator clips, put ALL three light bulbs in place
Series Circuits & Measuring Voltage
1. Construct a closed series circuit as shown in Circuit A.
**Note: the red wire is the positive end of the battery and the black wire is the negative end of the
battery
Circuit A
Circuit C
Circuit B
2. Measure and record the voltage across light bulb 1 by placing the tips of each lead from the
multi-meter on the wing nuts on either side of the light bulb.
3. Construct a closed series circuit as shown in Circuit B.
4. Measure and record the voltage across light bulb 1 and then light bulb 2.
5. Construct a closed series circuit as shown in Circuit C.
6. Measure and record the voltage across light bulb 1, light bulb 2 then light bulb 3.
Voltage (V)
Circuit A
Circuit B
Circuit C
Light Bulb 1
Light Bulb 2
Light Bulb 3
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Electrical Energy Kit Lesson Plan
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PARALLEL CIRCUIT & MEASURING CURRENT HANDOUT
1. Construct a closed parallel circuit as shown in Circuit X.
Circuit X
Circuit Y
Circuit Z
2. Measure and record the current through light bulb 1
a. Unclip the red alligator clip from light bulb 1 and clip it to the red lead of the multimeter.
b. Place the tip of the black lead from the multi-meter to the nut you unclipped the red
alligator clip from.
3. Construct a closed parallel circuit as shown in Circuit Y.
4. Measure and record the current through light bulb 1, and then light bulb 2.
a. To measure through light bulb 1 refer to step 2
b. To measure through light bulb 2
i. Unclip the red alligator clip from light bulb 2 and clip it to the red lead of the
multi-meter.
ii. Place the tip of the black lead from the multi-meter to the nut you unclipped the
red alligator clip from.
5. Construct a closed parallel circuit as shown in Circuit Z.
6. Measure and record the current across light bulb 1, light bulb 2, and then light bulb 3.
a. To measure through light bulb 1 refer to step 2
b. To measure through light bulb 2 refer to step 4b
c. To measure through light bulb 3
i. Unclip the red alligator clip from light bulb 3 and clip it to the red lead of the
multi-meter.
ii. Place the tip of the black lead from the multi-meter to the nut you unclipped the
red alligator clip from.
Current (A)
Circuit X
Circuit Y
Circuit Z
Light Bulb 1
Light Bulb 2
Light Bulb 3
** If you have extra time, measure the voltage across each light bulb in circuit Z and make an
observation **
Extra Challenge: Series and Parallel Circuit
See if your group can create a circuit that is both parallel and series. How can you test your circuit to see
if it is both parallel and series? Make a sketch on a separate piece of paper.
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Electrical Energy Kit Lesson Plan
Page 18
CAPACITOR HANDOUT
To charge the capacitor:
1. Using alligator clips, connect the battery to the capacitor, creating a complete circuit. The red side of the
capacitor (positive) should match the red side of the battery. Keep the circuit connected for at least 20
seconds to fully charge your capacitor. Disconnect from battery.
To use the capacitor:
2. Using alligator clips, connect the positive side of the capacitor (red) to one end of the resistor (needed to
regulate the power from the capacitor so the light doesn’t burn out).
3. Connect the negative side of the capacitor (black) to the red wire of the LED.
4. Have one member of your group cup their hands around the light and prepare to count out loud how many
seconds it stays lit up.
5. Have another group member connect the other end of the light to the other end of the resistor. The
completed circuit will look kind of like this:
6.
7.
8.
9.
Record the number of seconds in the chart below.
Remove the capacitor from the circuit and recharge it.
Using steps 1-6, perform the experiment twice for each capacitor bundle.
Calculate the values for the last column.
Bundles:
Trial #1
Trial #2
Average
(#1 + #2) ÷ 2
Dark Blue Capacitor
Dark Blue with 2 Light Blue Capacitors
3 Dark Blue Capacitors
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Electrical Energy Kit Lesson Plan
Page 19
IMAGE SOURCES
[1] BBC. A Complete Circuit. 2013. JPEG file.
http://www.bbc.co.uk/bitesize/ks3/science/energy_electricity_forces/energy_transfer_storage/revision/3/
[2] Brain, Marshall and Bryant, Charles W. How Capacitors Work. 2007. JPEG file.
http://www.howstuffworks.com/capacitor1.htm
EXTENDED RESOURCES
New York State Standards
http://www.emsc.nysed.gov/ciai/mst/pub/mststa4.pdf
http://stateaid.nysed.gov/scripts/sa/pi_find.idc
Introduction to DC Circuits
http://www.play-hookey.com/dc_theory/
Introduction to Capacitors
http://www.facstaff.bucknell.edu/mastascu/eLessonsHTML/LC/Capac1.htm
Exploring Science and Technology
http://www.ftexploring.com
http://electronics.howstuffworks.com/capacitor1.htm
REVISIONS
Date
Changes Made
Changes Made By
9/10/09
-Updated capacitor section (lesson plan &
handout)
Heather Godlewski
4/9/13
Updated format and edited for grammar and
syntax mistakes
Todd Jackson
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