2021 4E Pure Phy 6091 Preliminary Examination - Paper 3 (QP)

Name:…………………………………………….. Indexno:……… Class:…………… NGEEANNSECONDARYSCHOOL O PRELIMINARYEXAMINATION PUREPHYSICS 6091/03 PAPER3 17August2021 1h50min READTHESEINSTRUCTIONSFIRSTWriteyourname,classandindexnumberonalltheworkyouhandin.Writeindarkblueorblackpen.YoumayuseaHBpencilforanydiagramsorgraphs.Donotusestaples,paperclips,glueorcorrectionfluid. SectionAandBAnswer allquestions.Youwillbeallowedtoworkwiththeapparatusforamaximumof55minutesforeachsection.Youareexpectedtorecordallyourobservationsassoonastheyaremade. Candidates are reminded that all quantitative answers shouldincludeappropriateunits.Theuseofanapprovedscientificcalculatorisexpected,whereappropriate.Candidatesareadvisedtoshowalltheirworkinginaclearandorderlymanner, asmoremarksareawardedfor sounduseofPhysicsthanforcorrectanswers. Attheendoftheexamination,fastenallyourworksecurelytogether.Thenumberofmarksisgiveninbrackets[ ]attheendofeachquestionorpartquestion. Checkedbystudent:_____________________Date:__________________ Thisdocumentconsistsof12printedpages(includingthiscoverpage).

2 SectionA(20marks) 1 Inthisexperiment youwill measurethetimetakentoraisethetemperatureof water byaBunsenBurner. Youareprovidedwith:● A250mlbeaker,● athermometer,● a250mlmeasuringcylinder,● astand,bossandclamp,● astopwatch,● aBunsenBurner,● atripodwithwiregauze.(a) Fig1.1hasbeensetupforyou. Usingthemeasuringcylinder,take150mlofwaterandpouritintothebeaker.Thedensityofwateris1.0g/cm 3 .Notethat1.0ml=1.0cm 3 ,recordthemassmofthewaterinkilogram. m=………………………………(b) Notethetemperatureθ1 ofthewater. θ1 =………………………………[1] (c) UsingtheBunsenBurner,lightupthenon-luminousflame(withair-holefullyopenedandmaximumgassupply).Placeitunderneaththetripodstand,heatthebeakerofwaterandstartyourstopwatch.Heatthewaterfor1minute. Waitforafewminutesandrecordthehighest steadytemperatureθ2 reachedbythewater. θ2 =………………………………[1](d) TheheatenergyQ0 givenoutbytheBunsenBurnerisP.twherePisthepoweroftheBunsenBurner,tisthedurationofheatinginseconds.TheheatgainedbythewaterisQ1 =mcΔθ,wheremisthemassofthewaterinthebeakerinkg, c=4200JK -1 kg -1 andΔθ=θ2 -θ1 .QL istheheatlosttothesurrounding.NAS/2021/Prelim/4E/Physics/03/6091

3 Q0 =Q1 +QL P.t=m.c. Δθ+QL CalculatethevalueofQL intermsofPwiththecorrectunit. QL =……………………………..[2] (e) Plan Theequationin(d)canbere-arrangedtotheform Δθ=[P/(m.c)].t–[QL /(m.c)] UsingthesameapparatusprovidedinFig1.1,plananexperimenttoinvestigatetheaboverelationship.Theapparatusprovidedarenotexhaustive,youmayincludemoreapparatusinyourplan. Yourplanshouldinclude● alistofthequantitiesthatremainconstant,● adescriptionofhowyouwouldperformtheexperiment,● asuitabletableinwhichtodisplayyourmeasurementsandcalculatedvalues(youdonotneedtoenteranydataintothetable),● astatementofthegraphyouwouldplottotesttherelationship,● anexplanationofhowPandQL arefoundfromthegraph,● stateonekeysourceoferrorintheexperimentandhowdoyouovercomeit.…………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… ……………………………