Download Building Circuits Overview Directions

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Activitydevelop
BuildingCircuits
Whattypesofworkingcircuitsarethere?
Overview
Studentsexperimentwithbatteries,wires,bulbs,andswitchestoassembleseries
andparallelcircuitsandtotestforconductivityinsampleitems.
Forthecompleteactivitywithmediaresources,visit:
http://nationalgeographic.org/activity/building-circuits/
Program
Directions
1.Activatestudents’priorknowledgeaboutelectricity.
Findoutwhatstudentsalreadyknowaboutelectricity.Encouragethemtoidentify
objectsintheroomthatuseelectricity.Ask:Doyouknowhowelectricitytravelsto
powerthesedevices?(Electricitytravelsthroughcircuits.)Ask:Howiselectricity
usedinmorecomplicatedprojects,likepoweringarobot?Explainthatelectricityis
usedtoprovidepowertovariouspartsoftherobot,suchasmovingmechanical
parts,systemsthatprovidecontrolfortherobot(liketheCPU),anddatagatheringcomponents(likesensors).
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×
2.Introducetheconceptofacircuit.
Drawacircleontheboard.Ask:Istheshapeopenorclosed?(Itisclosed.)Now
drawacircularshapethatisnotcomplete,likea“u,”ontheboard.Ask:Isthis
shapeopenorclosed?(Itisopen.)Informstudentsthatinorderforelectricityto
flowandpoweradevice,theremustbeanunbroken,orclosed,pathway.Doa
quickdemonstrationusingtheroom’slights.Flipthelightoffintheclassroom.Tell
studentswhenthelightgoesoff,thecircuitisopenandelectricitycannotreach
thebulbtoproducelight.Referencetheshapespreviouslydrawnontheboard.
Flipthelightbackon.Tellstudentsthecircuitisnowclosedandelectricityisfreeto
travelandilluminatethebulb.
3.Studentsbuildasimplecircuittolightabulbwiththehelpofadiagramand
demonstration.
Telltheclasstheywillnowbuildaclosedsimplecircuittolightabulb.Showthe
classtheseparatepiecestheywilluse:aDcellbattery;theholderfortheDcell
battery;fouralligatorclipleads;a2.5volt,0.2amp,orsmallerbulbswithascrewtypebase;andtwobulbholders.Separatetheclassintoworkinggroupsof2-4
studentsanddistributethepartslistedabovetoeachgroup.Explainthattheir
groupgoalistoworktogethertobuildasimplecircuitthatwilllightthebulb.
Explainthatyouwilldemonstratehowtobuildacircuitandtheywillfollowalong,
butlaterontheywillneedtoworkintheirgroupstobuildacircuitontheirown.
Drawasimplecircuitdiagramontheboard,andlabelandexplainalloftheparts,
usingtheprovideddiagram.Walktheclassthroughbuildingthecircuitusingthe
HowtoBuildaSimpleCircuithandout.
Aftergroupshavesuccessfullylitthebulb,havethemmakealabeledsketchof
thecircuittheybuiltintheirnotebooks.Ask:Whatwouldhappenifaswitchwere
addedtothiscircuit?Provideeachgroupwithasingleknifeswitchandhavethem
updatetheircircuit.Elicitanswersfromstudentsthathelpthemmakeconnections
betweentheclosedcircuittheyjustbuilt,andtheearlierdemonstrationwiththe
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classroomlightthatcreatesanopenandclosedcircuit.Updatethediagramyou
previouslydrewontheboardtoincludeaswitchusingtheSimpleCircuitwith
Switchdiagramprovided.
4.Studentsbuildseriesandparallelcircuitsinsmallgroups.
Askstudentstoremovetheknifeswitchfromtheircircuit,sotheyhaveasimple
circuitagain.Asktheclasstopredictwhatwillhappenifanadditionalbulbisadded
tothesimplecircuit,withoutmakinganyotherchanges.(Again,theknifeswitch
shouldnolongerbeincludedinthecircuit.)Havestudentsrecordtheirpredictions
intheirnotebooks.Asstudentsaremakingpredictions,giveanadditionallightbulb
andbulbholdertoeachgroup.Then,allowgroupstimetoexperimentwithlighting
twobulbsonasinglepathway.Remindgroupsofwhatasingleclosedpathwayis
bydrawingattentionbacktothediagramontheboardandthefirstcircuitthey
built.Facilitateasneeded.UsetheprovidedHowtoBuildaSeriesCircuithandout
thatcontainsadiagramtocheckstudentwork.
Aftertheyhavesuccessfullybuilttheircircuits,tellstudentsthatthistypeofcircuit
iscalledaseriescircuit.Ithasasinglepathwayfromtheenergysource(battery)
throughaseriesofloads(bulbs)andbacktotheenergysource.Ask:What
happenedwhenasecondlightbulbwasadded?Explainthatthebulbsaredimmer
becausetheadditionalbulbslowstheflowofelectricityinthecircuit,causingthe
lightstodim.Ask:Whatmighthappenwiththeadditionofathirdbulb?Explain
theycouldexpectthebulbstobeevendimmerornotlightatall.Ask:Whatwould
happenifacomponentinthecircuitisdisconnectedorifthereisabrokenbulbin
thiscircuit?(Thecircuitwillbeopenandnoneofthebulbswillwork.)Have
studentsmakealabeledsketchoftheirseriescircuitintheirnotebooksand
recordtheirobservationsaboutbuildingthistypeofcircuit.
Posethefollowingquestiontotheclass:Ifonebulbinyourcircuitwentout,what
wouldbenecessaryinorderfortheotherbulbtoremainlit?Explainthatthe
configurationofthecircuitmustchangesobulbsareonseparateclosed
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pathwayswiththeenergysource.Allowtimeforgroupstoexperimentwith
buildingacircuitthatlightsbothbulbs,withtheadditionalchallengethatonebulb
mustremainlitwhenasinglecomponentisdisconnectedwithinthecircuit.
Facilitateasneeded.UsetheprovidedHowtoBuildaParallelCircuithandoutthat
containsadiagramtocheckstudentwork.
Explainthatthistypeofcircuitiscalledaparallelcircuit,wherebulbsare
connectedonseparatepathways.Eachbulbinaparallelcircuitwillbeequally
bright,butwilldrainthebatteryatanacceleratedrate.Havestudentscompare
andcontrasttheworkingmodelsofparallelcircuitscreatedbyeachgroup.Ask:
Wereallthegroups’parallelcircuitsthesame?Havestudentsmakealabeled
sketchoftheirparallelcircuitintheirnotebooksandrecordtheirobservations
aboutbuildingthistypeofcircuit.
5.Reviewthedifferenttypesofcircuits.
Reviewthesimilaritiesanddifferencesbetweenthefourdifferenttypesofcircuits
thatstudentsdiscussedduringtheactivity:open,closed,series,andparallel.Have
adiscussionabouttheapplicationsofeachtypeofcircuit.
Givestudentstheexampleofstreetlightsbeingconfiguredinparallelcircuits.
Remindthestudentsthatinaparallelcircuit,thecurrenttoeachload,likeabulb,
isseparate,soifonebulbburnsout,theotherswillstillwork.Asktheclass:Why
wouldthisbeuseful?(Becauseifonelightgoesout,therestwillstayon,ensuring
thesafetyofpeopleonthatstreet.)Encouragestudentstoshareother
applicationsineverydaylife.
Modification
Iftherearenotenoughmaterialsfortheseactivitiestobedoneinsmallgroups,
theteachercandothemasdemonstrationsusingstudentvolunteers.
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Modification
Toadaptthisactivityforyoungerstudents,completeactivitysteps1-3,thendo
theExtendingtheLearningsectionoftheactivity.
InformalAssessment
Havestudentsbuildworkingmodelsofseriesandparallelcircuitswithout
instruction.
ExtendingtheLearning
Studentsexaminetheconductivityofobjectsbytestingpredictionsabout
conductorswithintheircircuits.
Ask:Whyiselectricityabletoflowthroughawire?Explainthatwireismadeof
metalandmetalisagoodconductorofelectricity.Asktheclasstopredictwhat
kindsofmaterialstheythinkelectricitywillflowthrougheasilyandwhatmaterials
electricitywillnotflowthrougheasily.
Remindtheclassthatacircuitmustbeclosedforelectricitytoflowcontinuously
throughit.Showtheclassitemsfromaroundtheclassroom,suchasthe
following:apaperclip,apieceofstring,aneraser,arubberband,andapenny.
Invitestudentstopredictwhichitemswillbegoodconductorsandwhichwillnot
begoodconductors.Havestudentsrecordthesepredictionsintheirnotebooks
oronaseparatesheetofpaper.
Usethediagramsheetprovidedtoinstructgroupsinconstructingabrokencircuit
usingthreewires,abulb,andabattery.Havestudentsintroducetheitemsfrom
aroundtheclassroomintothecircuitbyattachinganalligatorclipinthecircuitto
twosidesoftheobject.Ifthebulblights,thentheitemisagoodconductor;ifthe
bulbdoesnotlight,theitemisnotagoodconductor.
Havestudentsrecordtheirresultsintheirnotebooksorontheirpaper,nextto
theiroriginalpredictions.Ask:Wereyourpredictionsaccurate?Whatobjectsmake
goodconductors,andwhatobjectsmakepoorconductors?Typicallyobjects
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madeofmetalaregoodconductorsandmostnon-metalmaterialsdonotconduct
electricitywell.
Objectives
Subjects&Disciplines
Science
Physicalsciences
Physics
LearningObjectives
Studentswill:
Constructsimple,series,andparallelcircuits
Understandandbeabletoexplainthedifferencebetweenseriesandparallel
circuits
Understandandbeabletoexplainthedifferencebetweenopenandclosed
circuits
TeachingApproach
Learning-for-use
TeachingMethods
Discoverylearning
Experientiallearning
Hands-onlearning
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SkillsSummary
Thisactivitytargetsthefollowingskills:
21stCenturyStudentOutcomes
LearningandInnovationSkills
CommunicationandCollaboration
CreativityandInnovation
CriticalThinkingandProblemSolving
CriticalThinkingSkills
Analyzing
Applying
Creating
Evaluating
Remembering
Understanding
ScienceandEngineeringPractices
Askingquestions(forscience)anddefiningproblems(forengineering)
Developingandusingmodels
Planningandcarryingoutinvestigations
NationalStandards,Principles,andPractices
NationalScienceEducationStandards
•(5-8)StandardA-1:
Abilitiesnecessarytodoscientificinquiry
•(5-8)StandardA-2:
Understandingsaboutscientificinquiry
•(5-8)StandardB-3:
Transferofenergy
•(K-4)StandardA-1:
Abilitiesnecessarytodoscientificinquiry
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•(K-4)StandardA-2:
Understandingsaboutscienceandtechnology
•(K-4)StandardB-1:
Propertiesofobjectsandmaterials
•(K-4)StandardB-3:
Light,heat,electricity,andmagnetism
NextGenerationScienceStandards
•Energy:
4-PS3-2.Makeobservationstoprovideevidencethatenergycanbetransferred
fromplacetoplacebysound,light,heat,andelectriccurrents.
•Energy:
4-PS3-4.Applyscientificideastodesign,test,andrefineadevicethatconverts
energyfromoneformtoanother.
•EngineeringDesign:
3-5-ETS1-2.Generateandcomparemultiplepossiblesolutionstoaproblembased
onhowwelleachislikelytomeetthecriteriaandconstraintsoftheproblem.
•EngineeringDesign:
3-5-ETS1-1.Defineasimpledesignproblemreflectinganeedorawantthat
includesspecifiedcriteriaforsuccessandconstraintsonmaterials,time,orcost.
•EngineeringDesign:
MS-ETS1-1.Definethecriteriaandconstraintsofadesignproblemwithsufficient
precisiontoensureasuccessfulsolution,takingintoaccountrelevantscientific
principlesandpotentialimpactsonpeopleandthenaturalenvironmentthatmay
limitpossiblesolutions.
•EngineeringDesign:
MS-ETS1-2.Evaluatecompetingdesignsolutionsusingasystematicprocessto
determinehowwelltheymeetthecriteriaandconstraintsoftheproblem.
•EngineeringDesign:
MS-ETS1-3.Analyzedatafromteststodeterminesimilaritiesanddifferences
amongseveraldesignsolutionstoidentifythebestcharacteristicsofeachthat
canbecombinedintoanewsolutiontobettermeetthecriteriaforsuccess.
•EngineeringDesign:
3-5-ETS1-3.Planandcarryoutfairtestsinwhichvariablesarecontrolledand
failurepointsareconsideredtoidentifyaspectsofamodelorprototypethatcan
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beimproved.
Preparation
WhatYou’llNeed
MaterialsYouProvide
1Dcellbatteryholderpergroup
1Dcellbatterypergroup
1singleknifeswitchpergroup
2,2.5volt,0.2amp,orsmallerminibulbswithascrew-typebasepergroup
2bulbholdersforminilampbulbspergroup
3alligatorclipleadspergroup
Itemstotestforconductivity:5paperclips,5piecesofstring,5erasers,5
rubberbands,5pennies(1ofeverythingpergroup)
RequiredTechnology
InternetAccess:Required
PhysicalSpace
Classroom
Setup
Setuproomsoitisconduciveforworkingingroupsoftwotofourstudents.
Grouping
Large-groupinstruction
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ResourcesProvided:Handouts&Worksheets
SimpleCircuitDiagram
HowtoBuildaSimpleCircuit
SimpleCircuitwithSwitchDiagram
HowtoBuildaSeriesCircuit
HowtoBuildaParallelCircuit
ExtendingtheLearning:BrokenCircuitSetup
Background&Vocabulary
BackgroundInformation
Electricityisusedtolighthousesandruntelevisions,computersandother
electronicdevices.Electricitycanpowervariousrobotcomponents,suchas
mechanicalplatforms,sensorsystems,controllers,andjoints.
Electricityisprovidedbyenergysourcessuchasgeneratorsorbatteries.
Generatorsconvertmechanicalenergyintoelectricity,andbatteriesconvert
chemicalenergyintoelectricity.
Electriccurrentistheflowormovementofelectrons(negativelycharged
particles).Highercurrentmeansmoreelectronsareflowingthroughacircuit.
Resistanceisameasureofhowdifficultitisforelectricitytoflow.Voltageishow
muchenergytheelectronshaveandissometimesdescribedashowhardtheyare
being“pushed.”Current,resistance,andvoltagearerelated:Thecurrent(in
amperes)inasimplecircuitisequaltothevoltage(involts)dividedbythe
resistance(inohms).
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Electricalconductorslikecopper,othermetals,andionicsolutions(likesaltwater)
arematerialsthatallowelectronstomovefreelythroughthem.Electricalinsulators
aredifficultforelectronstomovethrough.Aresistorreducesorlimitstheflowof
electrons(dimmerswitchesonlampscontainresistors).Acapacitorcontains
conductorsseparatedbyinsulators,andcanstoreelectriccharge,evenout
current,orreleasethechargeveryrapidly(asforacameraflash).
Aconductingloopiscalledacircuit.Circuitshavethreeessentialcomponents;a
conductivepathway(suchasacopperwire),anenergysource(suchasabattery
orgenerator),andaload(suchasalightbulboraheatingelementinatoaster).
Aclosedcircuitisanunbrokenpathwayandallowscurrenttoflow.Acircuitmust
beclosedinordertopoweralightbulborotherload.Anopencircuitisabroken
pathwaythatdoesnotallowcurrenttoflow.Anopencircuitcannotprovide
electricitytotheload.Aswitchisawaytoopenandcloseacircuit,byeither
allowingorstoppingtheflowofelectrons.Thewallswitchinmanyclassroomsand
homescontainsastripofmetalthatcontactsthecircuitinthe“on”position,
causingthelighttocomeon;whentheswitchisinthe“off”position,thecircuitis
broken,turningthelightoff.
Inaseriescircuit,aseriesofbulbsorotherloadsareconnectedinasingle
pathwaysoelectricityflowsthrougheachone.Withasinglepathway,ifawireis
cut,aswitchisopened,oraloadceasestowork,allloadswithinthecircuitwill
ceasetoworkbecausethepathhasbeeninterrupted.
Inaparallelcircuit,therearetwoormorepathwaysthroughwhichelectricitycan
flow.Thebulbsorotherloadsondifferentpathwaysinthiscircuitaresaidtobe
paralleltooneanother.Ifabulbinaparallelcircuitburnsout,electricitywillstill
flowtootherbulbsonotherpathways,allowingthebulbstocontinuetolight.
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PriorKnowledge
[]
RecommendedPriorActivities
None
Vocabulary
Term
battery
circuit
closed
circuit
Partof
Definition
Speech
devicecontainingoneormoreelectriccellswhichstore
noun chemicalenergythatcanbeconvertedintoelectricalpower.
noun
noun
completepathwaythroughwhichelectricityflows.
continuouspathwaythroughwhichelectricitycanflow.
conductive
pathway noun
courseofanelectricalcircuit.
electric
current
flowofelectricity,orchargedparticles,throughaconductor.
electricity
electron
noun
noun
noun
setofphysicalphenomenaassociatedwiththepresenceand
flowofelectriccharge.
negativelychargedsubatomicparticle.
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Term
energy
source
load
open
circuit
parallel
circuit
Partof
Definition
Speech
locationinwhichtheenergyresource(oil,coal,gas,wind,etc.)
noun isconvertedintoelectricalenergy.
noun
noun
noun
componentwithinacircuitthattransformselectricityintoa
differentformofenergysuchaslight,heat,orsound.
incompletepathwaythatprohibitsthefreeflowofelectricity.
pathway(closedcircuit)inwhichtheelectricalcurrentisdivided
intotwoormoreparallelpathsandreturnsthroughonepath.
Iftheloadsinthiscircuitarebulbsandoneblowsout,thereis
stillelectricityflowingtotheotherloads.
series
circuit
switch
noun
noun
electricalpathwaywherealltheloadsareconnectedin
sequence,formingasinglepathwaythroughwhichelectricity
canflow.
devicethatallowsanelectricalcircuittobeopenedorclosed.
ForFurtherExploration
Video
TechTopics:Electricity
Funder
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