Guide

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Theironcorebecomesastrong
magnetbecauseitallowselectrical
currenttoflow.
Theironbarsare
attractedtothecoil
Theironbarsarenot
attractedtothecoil
Let'scheckthepicturesbelow!Youcanseethere
ismagneticforcepresentbecauseitmakesthe
ironfilingscreateacirclearoundthemagnet.This
isvisibleproofthatthemagnetattractstheiron
filings.Theforcethatattractstheirontothe
magnetiscalledmagneticforce.
Whenthecoiliscarryinganelectriccurrent,
itattractsironlikeamagnet.Whenthecoilis
notcarryinganelectriccurrent,nothing
happens.
Whenthecoiliscarryinganelectriccurrent,
itattractsironlikeamagnet.Whenthecoilis
notcarryinganelectriccurrent,nothing
happens.
LetthecurrentflowLetthecurrentflow StopthecurrentStopthecurrent
Justlikeabar
magnet,anelectric
magnethas
magneticforce.
B B
C
Nothinghappens Theironbargetspulled
towardtheholeinthecoil
Theironbarisattracted
totheironcore
Nothinghappens Theironbargetspulled
towardtheholeinthecoil
Theironbarisattracted
totheironcore
Results
Whenyouputthecompass
besidetheelectromagnet
asshownbelow,thearrow
ofthecompasspointstoa
definitepoint.
Ifyouflipthebattery
(changethedirectionofcurrent),
thecompass'spoleswillswitch
position.
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Inserttheironcoreintothe
100-turncoil.Movethe
compasstowardtheironcorewhich
iscarryinganelectriccurrent,then
checkwhethertheelectromagnethas
anS-poleandN-poleornot.
Let'schecktheelectromagnet'spoles!
⑥Compass○Theassembledelectromagnet
Afterexperiment,flipthe
batterysothepolesare
reversed,thenmovethecompass
towardtheironcore,asin.
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Thediagramontherightshowsthedirectionof
themagnet'sforce.Thedirectionwhichis
shownonthecompassasaredmarkonthe
arrowiscalledthedirectionofmagneticfield.
Thelineswhichareshownonthecompassas
redmarksonthearrowarecalledmagnetic
fieldlines.Thisisthereasonwhythearrowof
thecompassindicatesadefinitepoint.
Themagneticfieldofanelectromagnetisthe
sameasforabarmagnet.
Unlikebarmagnets,
electromagnetscanchange
thedirectionoftheirpoles.
Whatyouneed
fromthekit:
Experiment
Welearnedtheelectromagnetattractsironwhenitcarriesan
electricalcurrent.DoestheelectromagnethaveanS-poleand
anN-polelikeamagnet?
Results
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Thedirection
ofmagneticfield
Magnetic
fieldlines
Turn
ON!
Enameledwire
Connectionplug
Ironcore
Compass
Batteryholder
Flipthebattery.
N SN S
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Check the pole of electromagnet