N5_Engineering-Science_QP_2023.pdf

N5 FOR OFFICIAL USE National Qualications Mark 2023 X823/75/01 Engineering Science TUES...

N5 FOR OFFICIAL USE National Qualications Mark 2023 X823/75/01 Engineering Science TUESDAY, 16 MAY 1:00 PM – 2:50 PM *X8237501* Fill in these boxes and read what is printed below. Full name of centre Town Forename(s) Surname Number of seat Date of birth Day Month Year Scottish candidate number Total marks — 110 SECTION 1 — 20 marks Attempt ALL questions. SECTION 2 — 90 marks Attempt ALL questions. Show all working and units where appropriate. You should refer to the National 4/5 Engineering Science Data Booklet which you have been given. The number of significant figures expressed in a final answer should be equivalent to the least significant data value given in the question. Answers that have two more figures or one less figure than this will be accepted. Write your answers clearly in the spaces provided in this booklet. Additional space for answers is provided at the end of this booklet. If you use this space you must clearly identify the question number you are attempting. Use blue or black ink. Before leaving the examination room you must give this booklet to the Invigilator; if you do not, you may lose all the marks for this paper. © *X823750101* A/PB  MARKS DO NOT WRITE IN THIS MARGIN SECTION 1 — 20 marks Attempt ALL questions 1. The parts of a doorbell, consisting of a button and speaker, are shown. button speaker (a) Complete the system diagram shown below for the doorbell by adding the missing output. 1 user input doorbell The doorbell operates without the use of feedback. (b) State the type of control that uses feedback. 1 *X823750102* page 02  MARKS DO NOT WRITE IN THIS MARGIN 2. A child’s game is shown. A diagram of the simple gear train inside the game is shown below. input speed 360 revs min−1 output speed 12 revs min−1 Calculate the velocity ratio of this simple gear train. 2 [Turn over *X823750103* page 03  MARKS DO NOT WRITE IN THIS MARGIN 3. A Boolean equation is shown. A B = Z Draw the logic diagram for this Boolean equation. 2 A Z B 4. A sign hanging from a supermarket ceiling is shown. cable A cable B Tinned fruit Tinned fish Tinned soup 18 A free body diagram of the sign is to be drawn. (a) Describe one piece of information that should be included on a free body diagram. 1 *X823750104* page 04  MARKS DO NOT WRITE IN THIS MARGIN 4. (continued) The sign hangs from the ceiling by two cables. Cable A has an original length of 4.5 m and is stretched by 0.0013 m. (b) Calculate the strain in cable A. 2 (c) State the nature of the force in cable A. 1 5. Part of a circuit is shown. V1 120 Ω (a) Calculate the voltage V1 across the 120 Ω resistor when the current flow is 0.0025 A. 2 The 120 Ω resistor is replaced by one with a larger resistance. (b) State the effect on the current if the voltage V1 remains the same. 1 [Turn over *X823750105* page 05  MARKS DO NOT WRITE IN THIS MARGIN 6. A drill uses a 1.5 A, 18 V rated battery. (a) Calculate the electrical energy supplied by the battery when the drill is used for 160 seconds. 2 Grease is used to lubricate the gear system within the drill. (b) Describe a reason for lubricating the gear system. 1 *X823750106* page 06  MARKS DO NOT WRITE IN THIS MARGIN 7. A lamp in a child’s night light will automatically switch on when the room is dark. The incomplete circuit diagram used to control the lamp is shown below. 5V component Y 0V (a) Complete this circuit diagram by adding the symbol for the lamp. 1 (b) State the full name of component Y in this circuit. 1 (c) Indicate, with a cross (X) on the circuit above, where an ammeter would be connected to measure the current flowing to the base connection of the transistor. 1 (d) State the name of the component that could be used to protect the transistor from a large input current. 1 [Turn over *X823750107* page 07  DO NOT WRITE IN THIS MARGIN SECTION 2 — 90 marks Attempt ALL questions 8. A car safety system detects when the driver’s seatbelt is unfastened. seatbelt strap clip and seatbelt sensor The safety system is operated by a microcontroller. Input and output connections to the microcontroller are shown in the table below. Input connections Pin Output connections 7 warning lamp 6 buzzer seatbelt sensor 0 The safety system operates using the following sequence: A warning lamp and a buzzer turn off. When the seatbelt sensor is on, the sequence will return to the start. If the seatbelt sensor is off, the warning lamp will turn on. The buzzer will then turn on and off three times over a total period of 1.8 seconds. The sequence will return to check the seatbelt sensor again. *X823750108* page 08  MARKS DO NOT WRITE IN THIS MARGIN 8. (continued) (a) Complete the flowchart for the sequence shown opposite, with reference to the Data Booklet and input/output connections. Include all pin numbers and delay units in your flowchart. 10 start pin 7 off pin 6 off No Yes *X823750109* page 09 [Turn over  MARKS DO NOT WRITE IN THIS MARGIN 8. (continued) A force applied to the seatbelt strap results in a stress of 15 N mm−2. The seatbelt strap has a cross-sectional area of 48 mm2. (b) Calculate the force applied. 3 *X823750110* page 10 [Turn over for next question DO NOT WRITE ON THIS PAGE *X823750111* page 11 9. A pneumatic circuit is used to arrange bottles ready for packaging in a production DO NOT WRITE IN line. THIS MARGIN The pneumatic circuit used to arrange the bottles is shown below. cylinder A 2 signal from microcontroller 4 1 cylinder B 5 3 *X823750112* page 12  MARKS DO NOT WRITE IN THIS MARGIN 9. (continued) (a) Describe the operation of the circuit shown opposite. 5 When a signal is received from the microcontroller... [Turn over *X823750113* page 13  MARKS DO NOT WRITE IN THIS MARGIN 9. (continued) Air at a pressure of 0.32 N mm−2 is supplied to cylinder B. This results in an outstroking force of 620 N. (b) (i) Calculate the area of the piston. 3 (ii) Calculate the diameter of the piston. 3 *X823750114* page 14  MARKS DO NOT WRITE IN THIS MARGIN 9. (continued) A microcontroller based system is used to detect the bottles. The program used to count six bottles is shown below. line program 1 main: let count = 0 2 check: if input2 is off then check 3 let count = count + 1 4 if count = 6 then label_1 5 goto check 6 label_1: switch on 7 7 pause 500 8 switch off 7 9 goto main (c) State the line number that contains a time delay. 1 An incomplete diagram for the microcontroller based system is shown below. (d) Complete, with reference to the program above, the wiring of the bottle sensor and the transistor to the microcontroller. 2 12 V 5V bottle sensor 0 7 1 6 2 5 3 4 0V signal to pneumatic circuit [Turn over *X823750115* page 15  [BLANK PAGE] DO NOT WRITE ON THIS PAGE *X823750116* page 16  MARKS DO NOT WRITE IN THIS MARGIN 10. A warning sign used on a road is shown. The warning sign uses a number of LEDs powered by solar energy. (a) Describe a task an electronic engineer would complete when designing the warning sign. 1 (b) Describe an economic impact of using LEDs instead of lamps in the warning sign. 1 (c) Explain an impact on the environment of using solar powered LEDs in the warning sign. 2 [Turn over *X823750117* page 17  MARKS DO NOT WRITE IN THIS MARGIN 10. (continued) Part of the circuit used in the warning sign is shown below. 390 Ω 82 Ω 78 Ω 86 Ω (d) (i) Calculate the resistance of the three LEDs in parallel. 3 (ii) Calculate the total resistance of the circuit shown above. 1 *X823750118* page 18  MARKS DO NOT WRITE IN THIS MARGIN 10. (continued) The warning sign is rated at 12 V, 1.8 W. (e) Calculate the current supplied to the warning sign. 3 [Turn over *X823750119* page 19  MARKS DO NOT WRITE IN THIS MARGIN 11. The mountain coaster shown below allows riders to travel downhill in an unpowered carriage. The rider can control the speed of the carriage by using a braking system. carriage track support structure brake lever wheels A number of different engineers were involved during the development and construction of the mountain coaster. (a) (i) Describe a task that a mechanical engineer would carry out during the development of the carriage. 1 (ii) Describe a task that a civil engineer would carry out during the development of the mountain coaster. 1 (iii) Describe a task that an environmental engineer would carry out during the construction of the track. 1 *X823750120* page 20  MARKS DO NOT WRITE IN THIS MARGIN 11. (continued) At the start of the ride, 6.2 m above the ground, the carriage and rider have a combined potential energy of 13 kJ. (b) (i) Calculate the combined mass of the carriage and rider. 3 (ii) Calculate the kinetic energy of the carriage and rider when released and travelling at a velocity of 2.7 m s−1. 2 [Turn over *X823750121* page 21  MARKS DO NOT WRITE IN THIS MARGIN 11. (continued) A structural engineer analyses the forces acting through part of the support structure for the track. A triangle of forces diagram used in the analysis is shown below. scale: 10 mm = 500 N 2600 N 2500 N F (c) Determine, with reference to the triangle of forces diagram, the size of unknown force F. 1 F= N The properties of the four metals considered for the support structure are shown in the table below. Corrosion Metal Durability resistant A no low B yes high C yes low D no high (d) Select the most suitable metal (A–D) from the table above to be used for the support structure and justify your choice. 2 Choice of metal Justification *X823750122* page 22  MARKS DO NOT WRITE IN THIS 12. A washing machine is shown. MARGIN A sub-system diagram showing the control of the water temperature in the washing machine is shown below. system temperature boundary sensor set water output heating actual water control temperature driver element temperature (a) Describe the reason for including a system boundary in a sub-system diagram. 1 (b) Describe, with reference to the sub-system diagram above, the control of the water temperature. 3 The water temperature is set... *X823750123* page 23 [Turn over  MARKS DO NOT WRITE IN THIS MARGIN 12. (continued) A thermistor is used in the temperature sensor. The operating characteristics of six thermistors are shown on the graph below. 10M 8 5 3 2 1M 8 5 3 2 100k 8 5 3 resistance (Ω) 2 10k 8 5 3 2 1k 5 8 5 4 6 3 2 2 1 3 100 8 5 3 2 10 −75 −50 −25 0 25 50 75 100 125150 200 250 300 temperature (°C) (c) State the thermistor number from the graph above that has a resistance of 1 kΩ when the temperature is 30 °C. 1 *X823750124* page 24  MARKS DO NOT WRITE IN THIS MARGIN 12. (continued) (d) Explain why using a low temperature wash cycle can affect climate change. 2 The washing machine’s heating element is tested using 8.6 kg of water. (e) Calculate the heat energy when the water temperature is raised by 15 °C. 2 [Turn over *X823750125* page 25  MARKS DO NOT WRITE IN THIS MARGIN 12. (continued) The logic diagram for part of a circuit used in the washing machine is shown. C A D B Z (f) Complete the truth table for this logic diagram. 3 A B C D Z 0 0 0 1 1 0 1 1 The truth table for another logic circuit in the washing machine is shown below. F G H Y 0 0 0 0 0 0 1 0 0 1 0 0 0 1 1 0 1 0 0 0 1 0 1 1 1 1 0 1 1 1 1 0 (g) Complete the Boolean equation for output Y in terms of inputs F, G and H. 3 Y= *X823750126* page 26 [Turn over for next question DO NOT WRITE ON THIS PAGE *X823750127* page 27  MARKS DO NOT WRITE IN THIS MARGIN 13. A combine harvester used to gather crops is shown below. reel cutter bar (a) State the type of motion shown above at the: 2 reel cutter bar A simplified diagram for the combine harvester is shown. 32 kN 82 kN 2.4 m 1.8 m 2.6 m RA RB front wheel back wheel *X823750128* page 28  MARKS DO NOT WRITE IN THIS MARGIN 13. (continued) (b) (i) Calculate the reaction force RA by taking moments about RB. 3 (ii) Calculate the reaction force RB. 2 [Turn over *X823750129* page 29  MARKS DO NOT WRITE IN THIS MARGIN 13. (continued) Part of a drive mechanism used in the combine harvester is shown. input 3750 revs min−1 gear B gear A 50 teeth 10 teeth gear C gear D 12 teeth output 250 revs min−1 (c) Calculate the number of teeth on gear D. 4 *X823750130* page 30  MARKS DO NOT WRITE IN THIS MARGIN 13. (continued) The combine harvester uses a Global Positioning System (GPS) when cutting the crop. This is an established technology. An emerging technology is one that is new and still to be tried commercially within a product or system. (d) Explain a possible impact of an emerging technology which you are familiar with. 2 Emerging technology Impact [Turn over *X823750131* page 31  MARKS DO NOT WRITE IN THIS MARGIN 14. A laminator is used to cover a sheet of paper in a plastic sleeve. The plastic sleeve is heated by the laminator as it passes through. The circuit used to indicate when the laminator is at the correct temperature is shown below. input sub-system +V Vs −t° red Vin green 0V (a) Describe the operation of the input sub-system as the temperature increases. Make reference to the resistance of the thermistor and the voltage Vin. 2 As the temperature increases... *X823750132* page 32  MARKS DO NOT WRITE IN THIS MARGIN 14. (continued) The input sub-system is shown below. 5.0 V −t° 1.7 kΩ 1.9 V 0V (b) Calculate the resistance of the thermistor for the condition shown above. 4 (c) Describe, with reference to the circuit shown opposite, the effect on the red LED and the green LED when the transistor first activates the relay. 2 When the transistor activates the relay... *X823750133* page 33 [Turn over  MARKS DO NOT WRITE IN THIS MARGIN 14. (continued) A possible modification to the circuit is to include an audible alert when the laminator is at the correct temperature. (d) Draw, in the circuit below, the symbol for a buzzer connected in parallel with the green LED. 2 +V red green *X823750134* page 34  MARKS DO NOT WRITE IN THIS MARGIN 14. (continued) An electronic engineer used computer simulation to test the modified circuit. (e) Describe an advantage of using computer simulation compared to building a circuit for testing purposes. 1 A large reduction in speed is required for a feed roller to slowly move the plastic sleeve and paper through the laminator. (f) Explain why a compound gear train is more suitable than a simple gear train to create this large reduction in speed in the laminator. 2 [END OF QUESTION PAPER] *X823750135* page 35  MARKS DO NOT WRITE IN THIS MARGIN ADDITIONAL SPACE FOR ANSWERS *X823750136* page 36  MARKS DO NOT WRITE IN THIS MARGIN ADDITIONAL SPACE FOR ANSWERS *X823750137* page 37  [BLANK PAGE] DO NOT WRITE ON THIS PAGE *X823750138* page 38  [BLANK PAGE] DO NOT WRITE ON THIS PAGE *X823750139* page 39  [BLANK PAGE] DO NOT WRITE ON THIS PAGE Acknowledgement of copyright Question 6 Cordless drill: doomu/shutterstock.com Question 9 Bottle machine: Alexander Tolstykh/shutterstock.com Question 11 Coaster: ELEPHOTOS/shutterstock.com Question 12 Washing machine: AmaPhoto/shutterstock.com Question 13 Harvester: Adazhiy Dmytro/shutterstock.com Question 14 Laminator: Anton Starikov/shutterstock.com *X823750140* page 40