Physics

RevisitingBooklet

Name:

7.MagnetismandElectromagnetism

MagnestismandElectromagnetism

Topics:

• Polesofamagnet

• Magneticfields• Electromagnetism

• Flemingslefthandrule(HTonly)

• Electricmotors(HTonly)

• Loudspeakers(HTonly)(Tripleonly)

• Inducedpotential(HTonly)

• Usesofthegeneratoreffect(HTonly)

• Microphones(HTonly)

• Transformers(HTonly)

PolesofaMagnet

DefineapermanentmagnetAmaterialthatis_________magnetic,makingitsown___________force.DefineaninducedmagnetWhenclosetoa__________thematerialactslikeamagnetWhenthemagnetleaves,thematerialisnot_____________anymoreDefinethepoleofamagnetApoleofamagnetiswherethemagneticfieldis_______________Completethetabletoshowtheobservationsthatwouldbemadeifthepolesoftwomagnetswerebroughttogether North SouthNorth South Repel

MagneticfieldsDefineamagneticfieldusingthekeywords:Region,magneticmaterials,wires,currents,force.Drawthemagneticfieldlinesaroundthemagnetbelow.Annotate:• Thepoles• Thedirectionofthefield• Thestrongestpartsofthefield

DescribehowacompassworksUsingtheimagedescribehowacompasscanbeusedtodrawthefieldlinesofabarmagnet

Electromagnetism

Amagneticfieldisproducedbycurrentflowingthroughawire.Drawthefieldlinesaroundasinglewireandawirewrappedinacoilaroundacoredtoformasolenoid.CurrentcarryingwireSolenoidDemonstrationofElectromagnetismUsingtheimagedescribehowelectromagnetismcanbedemonstrated.State3factorsthatwouldchangethestrengthofthemagneticfield

Current

(Tripleonly)YouwillbeshowncircuitswithelectromagnetsandaskedtoexplainhowtheyworkLookatthepicturebelow.Explainhowelectromagnetismisusedtomakethebellring

FLHR(HTONLY)DescribehowthedirectionofforcefromamagneticfieldcanbeascertainedusingFleming’slefthandrule.Labelthehandbelow(4pointstocover)

Statethethreefactorsthataffecttheforceactingonaconductorinamagneticfield1)2)3)Combinetheseequationstocreateanequationfortheforceactingonaconductorinamagneticfield.Defineallquantitiesandstatetheunitsforeach.

ElectricMotors(HTONLY)

Usingthediagramaboveexplainhowamagneticfieldisusedtocauseacurrentcarryingwiretospin

Loudspeakers(HTONLY)

Usingthediagramaboveexplainhowamagneticfieldisusedinaloudspeaker

InducedPotential(HTONLY)

Ifanelectricalconductormoves_________toamagneticfieldorifthereisachangeinthemagneticfieldarounda__________,a_____________________isinducedacrosstheendsoftheconductor.Iftheconductorispartofa___________circuit,acurrentisinducedintheconductor.Thisiscalledthe_____________________.Aninducedcurrentgeneratesa__________________thatopposestheoriginalchange,eitherthemovementoftheconductororthechangeinmagneticfield.

Conductor,Potentialdifference,CompleteRelative,Magnetic

FieldGeneratoreffect

1. Usingthefillinthegapsstatethetwowaysapotentialdifferencecanbeinducedacrosstheendsofaconductor

1.2.2. WhattwofactorswillaffectthesizeoftheinducedP.d?

1.2.3. Whatwillhappentothedirectionofthecurrentifthedirectionofthemagneticfieldisreversed?

4. Describeonesituationinvolvingthegeneratoreffect.Drawadiagraminyouranswe

Usesofthegeneratoreffect(HTonly)Readpg305oftheGCSEAQAtextbook1) Drawadiagramandexplainhowanalternatorworks.Foreachsketchagraphofpotentialdifferenceagainsttime.

2) Drawadiagramandexplainhowadynamoworks

Microphones

Usingthediagramaboveexplainhowamagneticfieldisusedinamicrophone.

Transformers

1) Statethefunctionofatransformer

2) Whatmaterialisatransformerusuallymadefromandwhy?

3) Thefollowingequationisgiveninthephysicsdatasheet.Definewhatismeantbyeachtermused.

4) WhatistheratioofVptoVsfor

a) Astepuptransformer

b) Astepdowntransformer5) Thefollowingequationisgiveninthephysicsdatasheet.Definewhatismeantbyeachtermused.

6) Whatquantityisgivenbypotentialdifferencexcurrent?

7) Usetheaboveequationtoexplainwhyelectricitytransmittedoverlargedistancesisgivenahigherpotentialdifferencebyastepuptransformer.