National 4XDOLÛFDWLRQV 2019 - SQA

2m ago
1.42 MB
40 Pages
Last View : 2m ago
Last Download : 1m ago
Upload by : Cannon Runnels

HFOR OFFICIAL USENationalQuali cations2019MarkX823/76/01Engineering ScienceFRIDAY, 17 MAY*X8237601*1:00 PM – 3:30 PMFill in these boxes and read what is printed below.Full name of centreTownForename(s)Date of birthDayMonthSurnameYearNumber of seatScottish candidate numberTotal marks — 110SECTION 1 — 20 marksAttempt ALL questions.SECTION 2 — 90 marksAttempt ALL questions.Show all working and units where appropriate.You should refer to the Higher Engineering Science Data Booklet which you have been given.The number of significant figures expressed in a final answer should be equivalent to the leastsignificant data value given in the question. Answers that have two more figures or one lessfigure than this will be accepted.Write your answers clearly in the spaces provided in this booklet. Additional space for answers isprovided at the end of this booklet. If you use this space you must clearly identify the questionnumber you are attempting.Use blue or black ink.Before leaving the examination room you must give this booklet to theInvigilator; if you do not, you may lose all the marks for this paper. *X823760101*B/PB

MARKSSECTION 1 — 20 marksAttempt ALL questions1.An electronic engineer requires the following circuit as part of a hand-heldproduct. It is to be made using individual integrated circuits (ICs).ABZC(a) Draw a NAND equivalent for the circuit shown above.3(b) Explain why the engineer chose to use the NAND equivalent circuit in theproduct rather than the original circuit.1*X823760102*page 02DO NOTWRITE INTHISMARGIN

MARKS2.A microphone in a recording studio produces a maximum output signal of2 0 mV.DO NOTWRITE INTHISMARGINThe following circuit is used to amplify the signal so that it can be recorded.330 kΩ Vcc 2·0 mV Vcc15 kΩVOUT0V(a) Calculate the output voltage from the op-amp shown above.1*X823760103*page 03[Turn over

MARKS2.(continued)(b) Describe how the gain of the op-amp circuit could be increased.1The mixing desk in the studio needs to combine the signals from a number ofmicrophones and instruments to produce one output signal for the speakers.(c) State the op-amp configuration required to perform this task.*X823760104*page 041DO NOTWRITE INTHISMARGIN

MARKS3.A frame structure is shown below.DO NOTWRITE INTHISMARGIN1·30 mA38 2·25 kNBCalculate the magnitude and indicate the direction of the reaction at B.4*X823760105*page 05[Turn over

4.An air pressure supply system in a car garage will be operated by programmablecontrol. The system must meet the following specification. The system is activated when a user presses a start button The pumping system then switches on The air pressure is monitored by an analogue sensor When the air pressure rises above a set level (100), the pump switches off A light must flash five times to indicate that the air pressure has reachedthe set level The system then resets, ready for the next userInputPinOutput7Pump6LightStart button1Pressure sensor0Part of the same test program is shown below in PBASIC and ARDUINO code.let dirs %11110000symbol pressure b4main: if pin1 1 then mainhigh 7check: readadc 0, pressureif pressure 200 then checklow 7for b3 0 to 5high 6pause 200low 6pause 200next b3goto mainint Pressure 0;int Pressuresensor 0;int Pump 7;int Light 6;int Startbutton 1;void setup(){pinMode (Pressuresensor, INPUT);pinMode (Startbutton, INPUT);pinMode (Pump, OUTPUT);pinMode (Light, OUTPUT);}void loop(){if (Startbutton LOW) {digitalWrite(Pump, HIGH);} else {digitalWrite(Pump, LOW);}Pressure analogRead (Pressuresensor);if (Pressure 200){digitalWrite (Pump, LOW);}for(int counter 0; counter 5;counter counter 1){digitalWrite(Light, HIGH);delay(200);digitalWrite(Light, LOW);delay(200);}}*X823760106*page 06DO NOTWRITE INTHISMARGIN

MARKS4.(continued)There are three faults in the program shown opposite.Identify the lines where the faults are and write the corrected code.2Complete for either PBASIC or ARDUINO.The first fault is shown below.Correction 1 PBASIC main: if pin1 0 then mainCorrection 1 ARDUINO if (Startbutton HIGH) {Correction 2Correction 3[Turn over*X823760107*page 07DO NOTWRITE INTHISMARGIN

MARKS5.A concurrent force system is shown below.690 NRθ43 64 840 NCalculate the magnitude and angle of the force R required to maintainequilibrium.*X823760108*page 084DO NOTWRITE INTHISMARGIN

MARKS6.The temperature in a room can be set by a signal from a mobile phone ordirectly using a control panel.A heating system monitors the temperature of the room and maintains theset temperature.3Complete the control diagram below for the heating of the ature[Turn over*X823760109*page 09DO NOTWRITE INTHISMARGIN

SECTION 2 — 90 marksMARKSAttempt ALL questions7.A prototype of an electrically powered aeroplane is being developed andtested by a team of engineers.The aeroplane is powered by 22 motor-driven propellers that each supply18 kW.(a) Calculate the rotational speed of each motor if it produces 23 N m oftorque.1When operating at full power the aeroplane is 73% efficient. The aeroplane’sbattery stores 320 MJ when fully charged.(b) Calculate how much time the aeroplane can run at full power before thebattery runs out.*X823760110*page 102DO NOTWRITE INTHISMARGIN

7.(continued)MARKSImproving efficiency is a key task for the engineers who design the aeroplane.(c) Explain one economic and one social impact of improving the efficiencyof the aeroplane.2EconomicSocialWhen the aeroplane lands, the propellers are used to transform its kineticenergy back into electrical energy to recharge the batteries as part of aregenerative braking system.The combined mass of the aeroplane and passengers is 4800 kg and theregenerative braking system is 64% efficient.(d) Calculate the energy recovered if the aeroplane’s velocity changes from95 m s 1 to 25 m s 1.[Turn over*X823760111*page 113DO NOTWRITE INTHISMARGIN

MARKS7.(continued)Bearings are required on the propellers to ensure that they can spin andtransfer kinetic energy to make the aeroplane move.(e) Explain, giving two reasons, why friction needs to be minimised in thebearings.*X823760112*page 122DO NOTWRITE INTHISMARGIN

MARKS7.(continued)DO NOTWRITE INTHISMARGINThe pilot controls the speed of the aeroplane by moving an accelerator lever.A signal is sent from the lever to a microcontroller which, in turn, sends asignal to an op-amp circuit and the motors’ drive systems.The op-amp circuit is shown below. Each pin from the microcontroller gives a5 0 V signal when on.5·0 V0V5·0 V12 kΩRf24 kΩ48 kΩ12 kΩ Vcc 24 kΩ Vcc 4·8 V Vcc VccVOUT0V(f)Calculate the value of the feedback resistor, Rf, when VOUT is 4 8 V.3*X823760113*page 13[Turn over

8.An exercise bike has an electronic monitoring system to tell users if they arepedalling within a set range of speeds.A speed sensor produces an output voltage, Vspeed, in proportion to the speedof the pedals.If the voltage is below the lower limit, a bank of LEDs lights to say, ‘SPEED UP’.If the voltage is above the higher limit, a second bank of LEDs lights to say,‘TAKE IT EASY’.The control circuit is shown below.5·0 V15 kΩ15 kΩVrefAVspeedbank Aop-amp A22 Ω9·0 V2·7 kΩ transistor A 9·0 V 0 V 15 kΩVrefB9·0 Vbank B22 Ω2·7 kΩ 9·0 Vop-amp B0V*X823760114*page 14transistor BDO NOTWRITE INTHISMARGIN

MARKS8.(continued)5·0 V15 kΩ15 kΩVrefAVspeed15 kΩVrefB0VA section of the circuit is shown above.2(a) Calculate the reference voltage VrefA.[Turn over*X823760115*page 15DO NOTWRITE INTHISMARGIN

MARKS8.(continued)A section of the circuit is shown.5·0 Vbank A22 Ωop-amp A9·0 V2·7 kΩ transistor A 9·0 V 0 V(b) (i) Calculate the base current for transistor A when op-amp A issaturated positive. (Assume Vbe is 0 70 V).3Transistor A has a gain (hFE) of 140.(ii) Calculate the collector current when op-amp A is saturated.*X823760116*page 161DO NOTWRITE INTHISMARGIN

MARKS8.(continued)DO NOTWRITE INTHISMARGIN5·0 V15 kΩ15 kΩVrefAVspeedbank Aop-amp A22 Ω9·0 V2·7 kΩ transistor A 9·0 V 0 V 15 kΩVrefB9·0 Vbank B22 Ω2·7 kΩtransistor B 9·0 Vop-amp B0V(c) Describe, with reference to the circuit diagram, what happens to theLEDs as the voltage from the speed sensor (Vspeed) rises from 0 V to 5 0 V.The complete circuit diagram is shown above again for reference.6*X823760117*page 17[Turn over

MARKS8.(continued)(d) Describe how the control circuit should be adapted to allow users tochange the speeds that switch on the LED banks.*X823760118*page 182DO NOTWRITE INTHISMARGIN

[Turn over for next questionDO NOT WRITE ON THIS PAGE*X823760119*page 19

9.A team of engineers is asked to design a walkway over a dinosaur exhibit fora natural history museum.An initial design for a walkway over the top of the exhibit is shown below.*X823760120*page 20DO NOTWRITE INTHISMARGIN

MARKS(continued)Tensile test results for three materials considered for use in the walkway areshown in the stress-strain graph below.450material Astress, σ (N mm 2)9.DO NOTWRITE INTHISMARGIN22019260550material Bmaterial Cstrain, ε(a) (i) Describe, with reference to the stress-strain graph, three differentproperties of material B in relation to material A or material C.3(ii) Identify, with reference to the Data Booklet, material A andmaterial C.2Material AMaterial C*X823760121*page 21[Turn over

MARKS9.(continued)A partially completed free body diagram of the design for the walkway isshown.DB60·0 55 65 CA24·2 kN(b) Calculate, using nodal analysis, the magnitude and nature of the forcesin members AB, AC, BC and BD.7Complete the table below.Show all working and final units on the page 3760122*page 22DO NOTWRITE INTHISMARGIN

9.DO NOTWRITE INTHISMARGIN(b) (continued)Space for working*X823760123*page 23[Turn over

MARKS10.A mechanical engineer produced a preliminary design for a pneumatic systemto open and close a dinosaur skeleton’s jaw.The pneumatic cylinder used to move the jaw has an 8·0 mm diameteraluminium alloy piston rod to support a load of 33 2 kN.(a) (i) Calculate the factor of safety applied to the design of the pistonrod.*X823760124*page 244DO NOTWRITE INTHISMARGIN

MARKS10.(a) (continued)(ii) Comment on the appropriateness of the factor of safety of thepiston rod.DO NOTWRITE INTHISMARGIN1The mechanical engineer decides to use a different pneumatic cylinderto support the 33 2 kN load.The piston rod area is 491 mm2 and is made from titanium alloy with alength of 0·78 m.(iii) Calculate the change of length in the piston rod under theseconditions.4*X823760125*page 25[Turn over

MARKS10.(continued)After testing, the pneumatic cylinder is repositioned to move a hinged beamin the jaw of the dinosaur as shown below.The uniformly distributed load of the jaw is 48 4 kN m 1.1·2 m0·90 m0·20 m48·4 kN m 174 FCYLINDER(b) (i) Calculate the magnitude of force FCYLINDER.(ii) Calculate the magnitude and direction of the reaction at the hinge.*X823760126*page 2634DO NOTWRITE INTHISMARGIN

[Turn over for next questionDO NOT WRITE ON THIS PAGE*X823760127*page 27

11.MARKSA proposed design for the operation of a conveyor belt motor has thefollowing specification.1.The motor will not run if emergency stop(A) is high2. The motor will run if a pressure sensor(B) is high and a light sensor(C) islow3.The motor will run if a test switch(D) is high(a) Complete the Boolean equation for when the motor switches on.M When the conveyor belt motor starts it uses pulse width modulation toaccelerate to a set speed.The control sequence for the acceleration of the conveyor belt motor has thefollowing steps. Initially the MARK 4 and the SPACE 2 Each new pulse increases the MARK by 1 The acceleration continues until the MARK reaches 20 The motor turns on The motor will then stop when the emergency stop is high or the overrideswitch is low A brake engages for 3 seconds The sequence repeatsINPUTPINOUTPUT7motor6brakeoverride switch (released 0)1emergency stop (pressed 1)0*X823760128*page 284DO NOTWRITE INTHISMARGIN

MARKS11.(continued)(b) Complete, with reference to the specification and input/output tableshown opposite, the flowchart for the control of the motor.DO NOTWRITE INTHISMARGIN13StartMARK 4 msSPACE 2 msNY*X823760129*page 29[Turn over

MARKS12.A pneumatic system will be used in a manufacturing process for holdingmaterial in place and then moving it along the production line. The systemdiagram is shown below.valve 5valve 9valve 7valve 8cylinder Acylinder Bvalve 4valve 3valve 6signalfromcontrolcircuitvalve 20Vvalve 1(a) Describe, making reference to the diagram above, the operation of thepneumatic circuit.When valve 1 is actuated,*X823760130*page 307DO NOTWRITE INTHISMARGIN

12.DO NOTWRITE INTHISMARGIN(a) (continued)[Turn over*X823760131*page 31

(continued)A diagram of the control circuit for the solenoid is shown below. The MOSFETswitches on when the gate voltage reaches 3 2 V. This happens when thethermistor is at 85 C.5·0 V12 Vsignal tosolenoid tetype 20V100585325 20 55100temperature ( C)*X823760132*page 326318532 322510Mresistance (Ω)12.DO NOTWRITE INTHISMARGIN

12.(continued)MARKS(b) Calculate, with reference to the graph opposite, the resistance of thefixed resistor to produce a gate voltage of 3·2 V.3The next stage of the manufacturing process requires a drive system.(c) Describe one skill and one piece of knowledge a mechanical engineerrequires to design the drive system.SkillKnowledge[Turn over*X823760133*page 332DO NOTWRITE INTHISMARGIN

MARKS12.(continued)Part of the design involves rotary motion, from a motor, transforming intolinear motion.rackmotorpinionThe pinion gear has 24 teeth and the pitch of the teeth on the rack is 3·0 mm.The rack is required to move 2 75 m in three seconds.(d) Calculate the required speed of the motor.*X823760134*page 343DO NOTWRITE INTHISMARGIN

MARKS12.(continued)Part of the circuit controlling the motor is shown below.12 VMVin0VThe motor has a rating of 12 V and 8 5 W.When the motor is switched on the MOSFET has a resistance of 0 65 Ω.(e) Calculate the MOSFET drain current.[END OF QUESTION PAPER]*X823760135*page 353DO NOTWRITE INTHISMARGIN





[BLANK PAGE]DO NOT WRITE ON THIS PAGEAcknowledgement of copyrightQuestion 2TZIDO SUN/shutterstock.comQuestion 8Julian Rovagnati/shutterstock.comQuestion 9Clari Massimiliano/shutterstock.comQuestion 10Marques/shutterstock.comQuestion 11Vivi-o/*X823760140*page 40

op-amp A 2·7 kΩ 22 Ω bank A transistor A 9·0 V 9·0 V (b) (i)Calculate the base current for transistor A when op-amp A is saturated positive. (Assume V be is 0 70 V). Transistor A has a gain (h FE) of 140. (ii) Calculate the collector current when op-amp A is saturated. 3 1

Related Documents:

SOFTWARE QUALITY ASSURANCE PLAN TEMPLATE TM-SQA-01 V2.0 DECEMBER 16, 2003 Systems Engineering Process Office, Code 212 Space and Naval Warfare Systems Center San Diego 53560 Hull Street San Diego, CA 92152-5001 Approved for public release; distribution is unlimited SQA Plan Template TM-SQA-01 v2.0 12/16/03 ii PREFACE

2018 Accounting Higher Finalised Marking Instructions Scottish Qualifications Authority 2018 The information in this publication may be reproduced to support SQA qualifications only on a non-commercial basis. If it is reproduced, SQA should be clearly acknowledged as the source. If it is to be used for any other purpose, written permission must be obtained from Where .

Businesses putting sustainable practices into actionsmsqa.comApril 21, 2016. Agenda SQA History SQA Winner Benefits Awards Event Eligibility: TDM City Ordinance Compliance Application and Categories Past Winners and Mentors Important Dates. SQA History

2019 Alfa Romeo Giulia 2019 BMW X7 2019 Alfa Romeo Stelvio 2019 BMW Z4 2019 Audi A3 2019 Buick Cascada 2019 Audi A4 2019 Buick Enclave 2019 Audi A5 2019 Buick Encore 2019 Audi A6 2019 Buick Envision 2019 Audi A7 2019 Buick LaCrosse 2019 Audi A8 2019 Buick Regal 2019 Audi Allroad

Section 1 question 1 — Reference to Chocolates of Glenshiel SQA has made every effort to trace the owners of copyright materials in this question paper, and seek permissions. We will be happy to incorporate any missing acknowledgements. Please contact question. Section 1 question 1 — Billion Photos/

Doctorate* Masters* Honours Degree* Ordinary Degree* Higher National Diploma Higher National Certificate . Customer Contact Centre 0345 279 1000 AD7071 The Scottish Credit and Qualifications Framework (SCQF) . and Computing to Care.

past papers by years visit the SQA website at The questions marked PP are practice papers produced by Visit the website for 100’s of free video lessons for National 5 and Higher Maths. The answers and worked solutions in these documents have been collated from a

HONOUR BOARD VOLUNTEERS 2019 - CURRENT David Staniforth Boorowa 2019 Bruce Gruber Boorowa 2019 Lindsay Cosgrove Boorowa 2019 Dennis Osborne Boorowa 2019 John Cook Boorowa 2019 Sue Cook Boorowa 2019 Mick Hughes Boorowa 2019 Daryl Heath Boorowa 2019 Lesley Heath Boorowa 2019 Russell Good Boorowa 2019 John Peterson Boorowa 2019 Heather Bottomley Boorowa 2019 James Armstrong Boorowa 2019

The Advanced Higher Biology question paper brief on the following page gives the structure of the SQA question paper , and the range of marks allocated to scientific problem-solving skills and knowledge and understanding. It gives the abbreviated codes for the knowledge and skills that are assessed. The question paper brief is a useful starting point to ensure that your questions have the .

The term Electrical Engineering in the context of this document covers the range of subjects traditionally included in SQA Higher Nationals in Electrical Engineering, namely power, plant and electrical installation. The title Electrical Engineering is intended to provide candidates, lecturers, Higher Education, employers and

2012 Geography Higher Paper 1 Finalised Marking Instructions Scottish Qualifications Authority 2012 The information in this publication may be reproduced to support SQA qualifications only on a non-commercial basis. If it is to be used for any other purposes written permission must be obtained from SQA’s NQ Delivery: Exam Operations.

2013 Geography Higher Paper 1 Finalised Marking Instructions Scottish Qualifications Authority 2013 The information in this publication may be reproduced to support SQA qualifications only on a non-commercial basis. If it is to be used for any other purposes written permission must be obtained from SQA’s NQ Assessment team.

2013 Accounting Higher - Solutions Finalised Marking Instructions Scottish Qualifications Authority 2013 The information in this publication may be reproduced to support SQA qualifications only on a non-commercial basis. If it is to be used for any other purposes written permission must be obtained from SQA’s NQ Delivery: Exam Operations.

SQA’s Skills Framework: Skills for Learning, Skills for Life and Skills for Work and draw from the following main skills areas: 1 Literacy 1.1 Reading 1.2 Writing 1.3 Listening and talking 5 Thinking skills 5.3 Applying 5.4 Analysing and evaluating Teachers and lecturers must build these skill

SKABT09B6 (SQA Unit Code - F9KM 04) Carry out waxing services SKABT09B6 Carry out waxing services 2 Performance criteria You must be able to: P1 maintain safe and effective methods of working when waxing by P1.1 preparing the work environment to meet legal, hygiene and industry Code of P

26 feet, nails and pads 27 ear condition 28 mouth, teeth and gums 29 skin and coat 30 internal and external parasites 31 eyes 32 genital and mammory area 33 anal glands 34 weight and condition score. LANAnC47- SQA Unit Code HA85 04 Assess and plan dog grooming work LANAnC

FT/CMMI/SUP/CMP 2.1 11/19 SUPPORT CM Audits and CM Reporting START Identify the types of audit to perform in the project (Baseline Audit or CM Audit) Baseline Audit perform by the Reviewer. CM Audit perform by SQA. SQA conducts the Phase End CM Audit base on CM Checklist and send QA report to PM. END CM

Differentiation Past Papers Unit 1 Outcome 3 1. Differentiate 2 3 p x with respect to x. A. 6 p x B. 3 2 3 p x4 C. 4 3 3 p x2 D. 2 3 3 p x2 2 Key Outcome Grade Facility Disc. Calculator Content Source D 1.3 C 0.83 0.38 NC C2, C3 HSN 091 PSfrag replacements Ox y [SQA] 2. Given f(x) 3x2(2x 1), nd f0( 1). 3 PSfrag replacements O x y [SQA] 3.

Higher Mathematics GCCStraightLine [SQA] 1. [SQA] 2. Find the size of the angle a that the line joining the points A(0, 1) and B(3 3,2) makes with the positive direction

the SQA (Scottish Qualifications Authority) academic system, and have completed all relevant short courses? If the answer is YES: you should be in possession of a SQA - HNC Nautical Science Part 1 certificate and it is likely that you completed it under the now ended Group Award Number G8F5 15.