SUPERVISOR TO ATTACH PROCESSING LABEL HEREVictorian Certificate of Education 2020

STUDENT NUMBER

Letter

SYSTEMS ENGINEERINGWritten examination

Monday 30 November 2020 Reading time: 9.00 am to 9.15 am (15 minutes) Writing time: 9.15 am to 10.45 am (1 hour 30 minutes)

QUESTION AND ANSWER BOOK

Structure of bookSection Number of

questionsNumber of questions

to be answeredNumber of

marks

A 20 20 20B 15 15 80

Total 100

• Studentsarepermittedtobringintotheexaminationroom:pens,pencils,highlighters,erasers,sharpeners,rulersandonescientificcalculator.

• StudentsareNOTpermittedtobringintotheexaminationroom:blanksheetsofpaperand/orcorrectionfluid/tape.

Materials supplied• Questionandanswerbookof28 pages• Detachableinsertofmiscellaneousformulasinthecentrefold• Answersheetformultiple-choicequestions

Instructions• Writeyourstudent numberinthespaceprovidedaboveonthispage.• Checkthatyourname andstudent numberasprintedonyouranswersheetformultiple-choice

questionsarecorrect, andsignyournameinthespaceprovidedtoverifythis.• Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.• AllwrittenresponsesmustbeinEnglish.

At the end of the examination• Placetheanswersheetformultiple-choicequestionsinsidethefrontcoverofthisbook.• Youmaykeepthedetachedinsert.

Students are NOT permitted to bring mobile phones and/or any other unauthorised electronic devices into the examination room.

©VICTORIANCURRICULUMANDASSESSMENTAUTHORITY2020

2020SYSENGEXAM 2

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Question 1Theleverinthediagramshownbelowisusedtoliftaloadof400N.

load = 400 N

1 m3 m

lever

ThemechanicaladvantageoftheleverisA. 4B. 3C. 0.33D. 0.25

Question 2

brown

black

green

gold

Whatisthevalueoftheresistorshowninthediagramabove?A. 1kΩB. 10kΩC. 1MΩD. 100kΩ

SECTION A – Multiple-choice questions

Instructions for Section AAnswerall questionsinpencilontheanswersheetprovidedformultiple-choicequestions.Choosetheresponsethatiscorrect orthatbest answersthequestion.Acorrectanswerscores1;anincorrectanswerscores0.Markswillnotbedeductedforincorrectanswers.Nomarkswillbegivenifmorethanoneansweriscompletedforanyquestion.Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.

3 2020 SYSENG EXAM

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Question 3

2 m

500 NP

The moment of the force F = 500 N about the point P in the diagram shown above isA. 2 N mB. 250 N mC. 500 N mD. 1000 N m

Question 4Which one of the following is a DC motor that moves in discrete steps?A. a dynamoB. an alternatorC. a stepper motorD. a brushless motor

Question 5A schematic diagram for an electronic circuit is shown below.

20 Ω

40 Ω 40 Ω

A1 A2

40 V

The electric current through ammeters A1 and A2 is respectivelyA. IA1

= 1 A and IA2 = 1 A

B. IA1 = 1 A and IA2

= 0.5 A C. IA1

= 0.5 A and IA2 = 0.5 A

D. IA1 = 0.5 A and IA2

= 0.25 A

2020 SYSENG EXAM 4

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Question 6A 4K7 resistor has a gold tolerance band. The expected range for this resistor isA. 3K76 to 5K64B. 4K23 to 5K17C. 4K47 to 4K94D. 4K61 to 4K79

Question 7The circuit below shows four load resistors that are connected to a 9 VAC power supply.

25 Ω20 Ω15 Ω10 Ω9 VAC

Which load resistor will dissipate the largest amount of energy in a 10-minute period?A. 10ΩB. 15ΩC. 20ΩD. 25Ω

Question 8Aschematicdiagramofasimpletransistoramplifiercircuitisshownbelow.

+6 V

input signal

RCR1

R2

RE

VoutputVinput

0 V

Toincreasetheefficiencyofthistransistoramplifiercircuit,whatmustbereduced?A. the size of the input signal VinputB. the size of the output signal VoutputC. thelossesinthetransistoramplifiercircuitD. thelengthoftimethatthetransistoramplifieroperates

5 2020 SYSENG EXAM

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Question 9The main purpose of using a three-dimensional (3D) modelling tool prior to fabricating and assembling the components of an engineering system is toA. ensure that the system is visually appealing.B. ensure compliance with occupational health and safety (OH&S) requirements.C. select the cheapest materials for fabricating components. D. identify potential issues or problems with the system design.

Question 10Whichoneofthefollowingisanexampleofatechnologicaldevelopmentusedbycoal-firedpowerstationsto reduce their environmental impact?A. burning off captured gasesB. using carbon capture and storageC. using brown coal instead of black coalD. applyingthin-filmsolarphotovoltaictechnology

Question 11The evaluation of a systems engineering solution involves an examination of its features and/or functions. Why is it necessary to conduct an evaluation of a systems engineering solution?A. to ensure that the solution looks goodB. to determine whether the solution will workC. to determine the cost effectiveness of the solutionD. todeterminehowwellthesolutionsatisfiesthedesignbrief

Question 12The forms of renewable energy that would be available in Victoria’s inland regions areA. wind,tidal,wave,hydro-electric.B. solar,hydro-electric,biomass,tidal.C. wind,solar,hydro-electric,biomass.D. solar,geothermal,wave,biomass.

2020 SYSENG EXAM 6

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Question 13Theelectricscootershowninthediagrambelowistravellingtotheright.Whenaccelerating,thewheelexertsaforceontheroad,asshown.

force of wheel on road

direction of movement

Which one of the following shows the direction of the corresponding action–reaction force according to Newton’s third law?

A.

B.

C.

D.

Question 14A shopper needs to go to a store one level up in a shopping centre and is carrying 10 kg of purchased items in a shopping bag. The shopper has three options for going up one level:• alift• asetofstairs• a20mramp

Which one of the following best describes the work that would be done on the shopping bag as the shopper goes up one level in the shopping centre?A. greatest for the stairsB. equal for all optionsC. greatest for the rampD. greatest for the lift

7 2020SYSENGEXAM

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Question 15Anoutputpistonandaninputpistonareconnectedinahydraulicsystem,asshowninthediagrambelow.Theoutputpistonhasadiameterof400mmandtheinputpistonhasadiameterof200mm.

output piston

input piston

200 mm400 mm

Ifaforceof100Nisappliedbytheinputpiston,whatistheforceontheoutputpiston,correcttothenearestnewton?A. 25NB. 50NC. 200ND. 400N

Question 16Thegearsystemshowninthediagrambelowisusedtochangetheplaneofdriveshafts.

ThistypeofgearsystemisknownasaA. bevelgear.B. spurgear.C. wormgear.D. compoundgear.

2020 SYSENG EXAM 8

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Question 17Twopulleys,AandB,areconnectedbyabelt,asshowninthediagrambelow.PulleyAhasadiameterof200mmandPulleyBhasadiameterof300mm.Anadditionalpulley,PulleyC,isusedasatensioner.Pulley C has a diameter of 100 mm.

A B

C

100 mm

300 mm200 mm

IfPulleyArotatesclockwiseat200revolutionsperminute(rpm),inwhatdirectionwillPulleyCrotateandat how many revolutions per minute?A. clockwise at 200 rpmB. clockwise at 400 rpmC. anticlockwise at 200 rpmD. anticlockwise at 400 rpm

Question 18The diagram below shows a rack and pinion gear.

What is the purpose of using a rack and pinion gear?A. changing clockwise motion to anticlockwise motionB. changing linear motion to rotational motionC. increasing torqueD. decreasing torque

9 2020 SYSENG EXAM

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Question 19Safety in the workshop should be a high priority in any engineering workshop. Which of the following lists common workshop safety actions in the correct order to minimise risk?

1st action 2nd action 3rd action 4th action 5th action

A. Identify tools. Identify risks. Use tools. Identify areas for improvement.

Document changes.

B. Use tools. Identify tools. Identify risks. Document changes.

Identify areas for improvement.

C. Document changes.

Identify risks. Use tools. Identify tools. Identify areas for improvement.

D. Identify tools. Identify areas for improvement.

Use tools. Document changes.

Identify risks.

Question 20The energy of water stored in a dam is to be used to generate electricity using a small turbine generator. Which of the following indicates the main energy transformations in the system as electricity is generated?A. electrical mechanical potentialB. kinetic mechanical electrical C. potential kinetic electricalD. kinetic electrical potential

2020SYSENGEXAM 10

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Question 1 (2marks)Figure1isablockdiagramofanautomatedandcontrolledsystem.

Figure 1

Usingthelistoftermsbelow,completetheblockdiagrambywritingtheappropriatetermineachoftheboxesprovided.

input feedback system output

SECTION B

Instructions for Section BAnswerall questionsinthespacesprovided.Allcalculationsmustshowappropriateformulasandworking.Whereananswerboxisprovided,writeyourfinalanswerinthebox.Ifananswerboxhasaunitprintedinit,giveyouranswerinthatunit.Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.

11 2020SYSENGEXAM

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Question 2 (6marks)Anelectricmotor,M,isusedtopullaloadonaninclinedplane,asshowninFigure2.

M

T B

A

3 m

4 m

Figure 2

a. TherequiredmechanicalworktomovetheloadfrompointAtopointBis3000J.

Calculatetheforce,T,requiredbytheelectricmotortopulltheloadfrompointAtopointB. Showyourworking. 2marks

N

b. Theelectricalenergyusedbytheelectricmotortolifttheloadis3192J.

CalculatetheefficiencyofmovingtheloadfrompointAtopointB.Giveyouranswercorrecttothenearestwholenumber.Showyourworking. 2marks

%

c. Calculatethemassoftheloadusingg=10ms−2.Showyourworking.Usethefollowingformula. 2marks

force=mass×accelerationduetogravity

kg

2020 SYSENG EXAM 12

SECTION B – Question 3 – continued

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Question 3 (10 marks)Figure 3 shows a schematic diagram for an electric circuit. The voltage of the power supply is 30 VDC,andtheresistorsR1,R2andR3areall60Ω.Initiallytheswitch,S,isopen.

A1 A2

V30 VDC R1 = 60 Ω

R2 = 60 Ω S

R3 = 60 Ω

Figure 3

a. Calculatetheexpectedreadingsonthevoltmeter,V,andtheammeters,A1 and A2. Show your working. 4 marks

Voltmeter V V

Ammeter A1 A Ammeter A2 A

b. Afteraperiodofcorrectfunctioning,acomponentinthecircuitdevelopsafault.Duetothisfault,thereadingonvoltmeterVbecomes30VandthereadingonammeterA1 becomes 0 A.

Identify the faulty component. Give your reasoning. 3 marks

13 2020SYSENGEXAM

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c. Afterreplacingthefaultycomponent,theswitchisclosed.

WhatisthepowerdissipatedbyresistorR1withtheswitchclosed?Showyourworking. 3marks

W

2020SYSENGEXAM 14

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Question 4 (3marks)Inthetablebelow,drawtheelectric/electronicsymbolforeachofthecomponentslisted.

Component Electric/electronic symbol

battery

PNPtransistor

variableDCpowersupply

capacitor

light-emittingdiode(LED)

light-dependentresistor(LDR)

15 2020SYSENGEXAM

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Question 5 (4marks)Asolarenergystoragesystemprovidespowerforanightlight,asshowninFigure4.Thestoragesystemreliesonacapacitor,X,tostorecharge.

night lightX

solar panel

Figure 4

a. Describethetypeofcapacitorthatwouldbebestsuitedtothisapplication.Giveyourreasoning. 2marks

b. Whatisthepurposeoftheresistorconnectedinseriestothelightsource?Giveyourreasoning. 2marks

2020SYSENGEXAM 16

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Question 6(7marks)ThecoolingunitofasmallrefrigeratoriscontrolledbyathermistorusingthecircuitshowninFigure5.

12 VDC

thermistor

variableresistor

Voutput

Figure 5

a. Explainthefunctionofthevariableresistor. 2marks

b. OnFigure5,indicatewhereanammetershouldbelocatedtomeasurethecurrentflowingthroughthethermistor. 1mark

c. Ifthevariableresistorissetat1kΩandVoutput=4V,calculatethepowerconsumedbythevariableresistor.Showyourworking.Youmustincludetheunit. 4marks

17 2020SYSENGEXAM

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Question 7 (6marks)Benhasdesignedandbuiltascaledversionofarescuerobotforretrievinginjuredchildren.Hisprojectusesawinchsubsystemthatisconnectedtoa12VDC-poweredmotorviaachainandsprocketmechanism.ThisrescuerobotisshowninFigure6.

winch

motor

Figure 6

a. ExplainwhyBenshoulddesignandmodeltherescuerobot’ssubsystem. 2marks

b. ProposeoneappropriatediagnostictestthatBenshouldconsiderforthemotorisedchainandsprocketmechanism.Giveyourreasoning. 2marks

c. Evaluationisanimportantpartofthesystemsengineeringprocess.

i. WhyisitimportantforBentoevaluatehisrescuerobotsubsystem? 1mark

ii. WhenshouldBenevaluatehisrescuerobotsubsystem? 1mark

2020 SYSENG EXAM 18

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Question 8 (5 marks)Figure 7 shows a typical wind farm used to generate renewable energy.

Source:PremierofVictoria(website),‘Araratwindfarmpoweringahead’, mediarelease,27June2017;©StateofVictoria

Figure 7

a. What type of current would the wind turbines shown in Figure 7 typically produce? 1 mark

b. Identify twofeaturesofthewindturbinethatcouldbemodifiedtoimproveitsefficiency. 2 marks

c. Explain one way in which computer simulation software can assist engineers in the design of wind turbine blades. 2 marks

19 2020SYSENGEXAM

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Question 9 (3marks)Aroboticpoolcleanerhasapowerratingof2000Wandthemotorissuppliedfromthemainpowersupplyusingatransformer.Fourprocesses,includingoneunknownprocess,runbytheroboticpoolcleanerarelistedinthetablebelowwiththeirrespectivepowerconsumptions.

Robotic pool cleaner process Power consumption

motordrive 1000W

waterpump 650W

soundfromthemotorortransformer 45W

unknown 305W

a. Suggestonepossibleroboticpoolcleanerprocessfortheunknownprocesslistedinthetableabove. 1mark

b. Calculatetheoverallefficiencyoftheroboticpoolcleanersystemifthemotordriveandthewaterpumpareconsideredusefulprocesses.Showyourworking. 2marks

%

2020 SYSENG EXAM 20

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Question 10 (6 marks)Figure 8 shows part of a simple steering system using a worm drive and levers to change the direction of the front wheels on a car.

drop arm

to steering rack

spur gear

to steering wheel housing

worm drive

Figure 8

a. State one advantage of using the worm drive as the initial input to the steering system. 1 mark

b. Ifthespurgearhadsevenworkingteeth,withonlyonetoothmeshingwiththewormdriveatanytime,whatisthegearboxratio? 1 mark

21 2020SYSENGEXAM

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c. ThesteeringmechanismshowninFigure9aissimplifiedintothelevershowninFigure9b.

100 mm

250 mm

point A

spur gear

worm drive

100 mm

250 mm

point A

pivot pointF = 200 N

Figure 9a Figure 9b

Whenthedriverofthecarturnsthesteeringwheel,theforceexertedonthespurgearis 200N,asshowninFigure9b.

CalculatetheforceatpointAonthesteeringarm.Showyourworking.Youmustincludetheunit. 4marks

2020SYSENGEXAM 22

SECTION B – Question 11 –continued

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Question 11 (5marks)Jemmahasdesignedasmallelectricmotor-drivencaraspartofaschoolprojecttoinvestigatedrivemechanisms.Shehasusedarubberbandbeltdrivesystemtoconnectthemotortothewheels,asshowninFigure10.

motor

rubber bandbelt drive

Figure 10

a. Whatisoneadvantageofusingarubberbandbeltdrivesystemforasmallelectric motor-drivencar? 1mark

23 2020SYSENGEXAM

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Aclose-upoftherubberbandbeltdrivesystemisshowninamodifiedset-upinFigure11.Thespeedofthewheelis40revolutionsperminute(rpm).

75 mm

wheel

motor Ø 5 mm

Figure 11

b. UsetheinformationgiveninFigure11toanswerthefollowingquestions.

i. Calculatetheexpectedspeedofthesmallelectricmotor-drivencarinmetresperminute.Showyourworking. 2marks

mmin–1

ii. Convertyouranswerfrompart b.i.tometrespersecond.Showyourworking. 1mark

ms–1

c. Jemmawouldlikethesmallelectricmotor-drivencartobeabletoreachahighermaximumspeed.

SuggestonechangeJemmacouldmaketohercartoachievethis. 1mark

2020SYSENGEXAM 24

SECTION B – Question 12 –continued

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Question 12 (7marks)Figure12showsacross-sectionalfrontviewofasewingmachine.Thesewingmachineusesabelttoconnectthemotortothedrivewheel,asshown.

drive wheel

belt

motor wheelmotor

drive shaft

crankshaft

needle bar

needle

A

Figure 12

a. Describetheroleoffrictionbetweenthebeltandthedrivewheel. 2marks

b. Themotorwheelhasadiameterof20mm.Thedrivewheelhasadiameterof180mm.

Calculatetherotationspeedofthemotorwheelforthedrivewheeltospinat150rpm.Showyourworking. 2marks

rpm

25 2020SYSENGEXAM

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c. Figure13showsacross-sectionalviewlookingfrompointAinFigure12directlyatthecrankshaft.

linear bearings

needle

drive shaft

crankshaft

needle bar

sewing foot

Figure 13

UsingtheadditionalinformationprovidedinFigure13,explainhowtherotationalmovementofthemotoristransformedintothereciprocatingmotionofthesewingneedle. 3marks

2020SYSENGEXAM 26

SECTION B – Question 13 –continued

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Question 13 (8marks)Charlieisdeliveringalargeheavyboxusingatiptruckwithatraythatcanbetiltedatanangle,asshowninFigure14.Whenunloadingthebox,heobservesthattheboxdoesnotstartmovinguntilthetrayistiltedatacertainangle,A.AsthetrayisraisedabovetheangleA,theboxslidesdownwards.

Ahydraulic ram

tray

pivot

box

Figure 14

a. Whatclassofleveristhetiptruck’stray? 1mark

b. AttheangleA,theboxstartstomove.

UsingNewton’slaws,explainwhythishappens. 3marks

27 2020SYSENGEXAM

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c. Thetiptruckusesahydraulicsystemtoraisethetray,asshowninFigure15.

Ø 50 mm

Ø 250 mm

hydraulic ram

6000 N

Figure 15

Toliftthetrayandthebox,thepistonmustexertaforceof6000Nontheundersideofthetray.

CalculatethepressureneededintheshadedareaofFigure15tocreatethe6000Nforcerequired.Showyourworking. 2marks

kPa

d. Figure16showsthehydraulicraminthefullyextendedposition.TworegionsoftherodarelabelledpointBandpointC.

hydraulic ramB

C

Figure 16

Fourtypesofstressaregivenbelow.

tension compression torsion shear

Fromtheoptionsgiven,selectthetypeofstressonpointBandonpointC,andwriteyouranswersintheboxesprovidedinFigure16. 2marks

2020SYSENGEXAM 28

END OF QUESTION AND ANSWER BOOK

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Question 14 (3marks)Input-process-output(IPO)diagramscanbeusedtobreakdownanysystemintosmallerpartsforanalysis.IPOdiagramsallowtheidentificationoftheinputsandoutputsofasystemandanyprocessesthattakeplace.

CompletetheIPOdiagraminFigure17foracordlessdrillmotorsystembywritingappropriatelabelsintheboxesprovided.

Figure 17

Question 15 (5marks)ThenumberofelectricvehiclesonAustralianroadsiscurrentlylowerthaninotherdevelopedcountries,butthenumberisexpectedtogrowascheapermodelsarriveandmorecharginginfrastructureisbuilt.

EvaluatethepotentialbenefitsandchallengesofusingelectricvehiclesinAustraliaintermsofeconomicandenvironmentalsustainability.

SYSTEMS ENGINEERING

Written examination

FORMULA SHEET

Instructions

Please remove from the centre of this book during reading time.This formula sheet is provided for your reference.

© VICTORIAN CURRICULUM AND ASSESSMENT AUTHORITY 2020

SYSENG EXAM 2

THIS pAGE IS bLANk

3 SYSENG EXAM

END OF FORMULA SHEET

Systems Engineering formulas

gear ratio final = gear ratio 1 × gear ratio 2 efficiency = output energyinput energy

× 100%

gear ratio = number of teeth on driven gearnumber of teeth on driver gear efficiencyTotal = efficiency1 × efficiency2

gear A rpmgear B rpm

number of teeth gear Bnumber of teeth

= gear A mechanical advantage load

effort=

pulley A rpmpulley B rpm

radius of pulley Bradius of pulle

=yy A force = pressure × area

voltage = current × resistance torque = force × distance

power = voltage × current frequency = 1period

area of circle = r2 ( = 3.14) speed = distancetime

circumference of circle = 2r

resistors in series Rt = R1 + R2 + R3 + … capacitors in series1

C= 1

C+ 1

C1

Ct 1 2 3+

…

resistors in parallel 1 1 1 1

2 3R R R Rt 1= + +

… capacitors in parallel Ct = C1 + C2 + C3 + …

two resistors in parallel R R RR Rt = +

×1 2

1 2

Colour codes

Colour Value Colour Value

black 0 blue 6

brown 1 violet 7

red 2 grey 8

orange 3 white 9

yellow 4 gold 5%

green 5 silver 10%