Systems & Control – Electronics — Paper 3 · IGCSE Design and Technology 0445

8 Fig. 7 shows a battery with a test strip. When the contacts at each end are pressed, a current flows through the strip which then indicates how much charge is left in the battery. Fig. 7 Complete the statement below by adding the correct term from the list. conductive fabricating thermochromic laser The battery tester is an example of … technology. [1]

1 marks

Mark scheme: 8 Thermochromic 1

This question in 0445/31 May/June 2018

8 Fig. 7 shows a battery with a test strip. When the contacts at each end are pressed, a current flows through the strip which then indicates how much charge is left in the battery. Fig. 7 Complete the statement below by adding the correct term from the list. conductive fabricating thermochromic laser The battery tester is an example of … technology. [1]

1 marks

Mark scheme: 8 Thermochromic 1

This question in 0445/33 May/June 2018

8 Name the type of soldering that could be used when joining: (a) electronic components to a circuit board; … [1] (b) nickel silver jewellery. … [1]

2 marks

Mark scheme: 8(a) Soft 1 8(b) Hard or silver 1

This question in 0445/32 Oct/Nov 2018

11 Fig. 9 shows views of a child’s counting toy. When the discs are stacked on the rod, the collar slides down on top of the discs to show the number of discs stacked. Ø5 rod collar 10 9 8 upright 7 discs 6 5 4 base 3 2 1 disc Ø40 × 15 Fig. 9 (a) Fig. 10 shows the base of the counting toy. The base is made from beech. slot 40 × 12 15 centre for hole 150 100 Fig. 10 (i) Give two reasons why beech is commonly used to make children’s toys. 1 … 2 … (ii) Name three marking out tools, other than a pencil, that could be used to mark out the centre for the hole and the slot. 1 … 2 … 3 … [3] (iii) Describe how the slot could be cut out 10 mm deep to take the upright. … … … … … [3] (b) The Ø5 rod is made from non-ferrous metal. (i) Name a suitable non-ferrous metal for the rod. … [1] (ii) Give one reason why a non-ferrous metal could be more suitable than a ferrous metal for the rod. … [1] (c) Use sketches and notes to show how ten identical wooden discs could be made in a school workshop. Show clearly how the holes in each disc could be produced accurately. [5] (d) The discs could also be made from plastic and produced by injection moulding. Give two advantages of using the injection moulding process to produce plastic discs rather than making them from wood. 1 … 2 … [2] (e) Fig. 11 shows a length of beech that will be used to make the four parts of the collar. 25 45 collar 6 Fig. 11 Use sketches and notes to show how the collar could be constructed. Name the tools and equipment used to construct the collar. [4] (f) Describe how CAD/CAM could be used to produce the numbers on the upright. … … … … … … [4]

25 marks

Mark scheme: 11(a)(i) Hardwearing, tough, close grain, does not split easily, good finish, doesn’t chip easily, can be bent to shape, non-toxic, aesthetically pleasing 2 × 1 2 Do NOT accept strong or durable, cheap, easy to work, lightweight 11(a)(ii) 3 marking out tools: steel rule, try square, engineers try square, marking knife, mortise/marking gauges 3 × 1 3 Do NOT accept metalworking tools or any form of felt tip/marker pens 11(a)(iii) Slot cut out: chisel and mallet, mortise machine or drilled holes chiselled out, plunge router, check depth of holes 2 × 1 stages Award 1 mark for technical accuracy 1 3 For example: router or mortise machine =1 + details can = 3 marks 11(b)(i) Brass, aluminium, copper, duralumin, gilding metal 1 11(b)(ii) Can provide an attractive clear finish that does not corrode/rust 1 Accept takes a long time to corrode 11(c) Method 1: Between centres wood turning. Award 0–5 marks for each relevant detail in process including: preparing the wood before setting up, correct set up, use of gouges/scrapers to make round, parting off. Method 2: Make each disc individually by marking out a circle, cutting to shape and finishing on disc sander, hole drilled, method of achieving identical discs 5 × 1 Method 3: Use of hole saw. Accurate sketch of hole saw and mandrel 0–2, fitted into drill 1, wood held securely 1, hole drilled and disc removed 1. 5 Question Answer Marks Guidance 11(d) 2 advantages: quicker process [after mould has been produced], repetitive consistency/accuracy, smoother finish, inherent colours, less waste. 2 × 1 2 Cheaper must be qualified Do NOT accept easier to do 11(e) Lengths marked out 1 Lengths cut 1 Sides joined appropriately: pin and glue, glued butt, mitre, finger, lapped 0–2 4 Do NOT accept dowel 11(f) CAD: used to design the numbers on screen, change font, size, on-screen modelling, data transferred/downloaded to CNC machine. 0–2 CAM: numbers engraved into surface or applied to surface; use of specific machine such as CAMM 1 vinyl cutter or CNC router set up, tool parameters. 0–2 4 Reward answers that demonstrate genuine knowledge of CAD-CAM. Accept laser cutter = 1 mark Details required re set up etc. 4 × 1

This question in 0445/31 May/June 2019

11 Fig. 9 shows views of a child’s counting toy. When the discs are stacked on the rod, the collar slides down on top of the discs to show the number of discs stacked. Ø5 rod collar 10 9 8 upright 7 discs 6 5 4 base 3 2 1 disc Ø40 × 15 Fig. 9 (a) Fig. 10 shows the base of the counting toy. The base is made from beech. slot 40 × 12 15 centre for hole 150 100 Fig. 10 (i) Give two reasons why beech is commonly used to make children’s toys. 1 … 2 … (ii) Name three marking out tools, other than a pencil, that could be used to mark out the centre for the hole and the slot. 1 … 2 … 3 … [3] (iii) Describe how the slot could be cut out 10 mm deep to take the upright. … … … … … [3] (b) The Ø5 rod is made from non-ferrous metal. (i) Name a suitable non-ferrous metal for the rod. … [1] (ii) Give one reason why a non-ferrous metal could be more suitable than a ferrous metal for the rod. … [1] (c) Use sketches and notes to show how ten identical wooden discs could be made in a school workshop. Show clearly how the holes in each disc could be produced accurately. [5] (d) The discs could also be made from plastic and produced by injection moulding. Give two advantages of using the injection moulding process to produce plastic discs rather than making them from wood. 1 … 2 … [2] (e) Fig. 11 shows a length of beech that will be used to make the four parts of the collar. 25 45 collar 6 Fig. 11 Use sketches and notes to show how the collar could be constructed. Name the tools and equipment used to construct the collar. [4] (f) Describe how CAD/CAM could be used to produce the numbers on the upright. … … … … … … [4]

25 marks

Mark scheme: 11(a)(i) Hardwearing, tough, close grain, does not split easily, good finish, doesn’t chip easily, can be bent to shape, non-toxic, aesthetically pleasing 2 × 1 2 Do NOT accept strong or durable, cheap, easy to work, lightweight 11(a)(ii) 3 marking out tools: steel rule, try square, engineers try square, marking knife, mortise/marking gauges 3 × 1 3 Do NOT accept metalworking tools or any form of felt tip/marker pens 11(a)(iii) Slot cut out: chisel and mallet, mortise machine or drilled holes chiselled out, plunge router, check depth of holes 2 × 1 stages Award 1 mark for technical accuracy 1 3 For example: router or mortise machine =1 + details can = 3 marks 11(b)(i) Brass, aluminium, copper, duralumin, gilding metal 1 11(b)(ii) Can provide an attractive clear finish that does not corrode/rust 1 Accept takes a long time to corrode 11(c) Method 1: Between centres wood turning. Award 0–5 marks for each relevant detail in process including: preparing the wood before setting up, correct set up, use of gouges/scrapers to make round, parting off. Method 2: Make each disc individually by marking out a circle, cutting to shape and finishing on disc sander, hole drilled, method of achieving identical discs 5 × 1 Method 3: Use of hole saw. Accurate sketch of hole saw and mandrel 0–2, fitted into drill 1, wood held securely 1, hole drilled and disc removed 1. 5 Question Answer Marks Guidance 11(d) 2 advantages: quicker process [after mould has been produced], repetitive consistency/accuracy, smoother finish, inherent colours, less waste. 2 × 1 2 Cheaper must be qualified Do NOT accept easier to do 11(e) Lengths marked out 1 Lengths cut 1 Sides joined appropriately: pin and glue, glued butt, mitre, finger, lapped 0–2 4 Do NOT accept dowel 11(f) CAD: used to design the numbers on screen, change font, size, on-screen modelling, data transferred/downloaded to CNC machine. 0–2 CAM: numbers engraved into surface or applied to surface; use of specific machine such as CAMM 1 vinyl cutter or CNC router set up, tool parameters. 0–2 4 Reward answers that demonstrate genuine knowledge of CAD-CAM. Accept laser cutter = 1 mark Details required re set up etc. 4 × 1

This question in 0445/33 May/June 2019

12 Fig. 12.1 shows a storage unit with adjustable shelves that will be used in a bathroom. The storage unit is made from acrylic and could be produced in a school workshop by means of hand tools and CAD / CAM. top Ø240 upright height of storage unit 300 mm shelf slot shelf base Fig. 12.1 (a) Give two benefits of using acrylic to make products that will be used in a bathroom. 1 … 2 … [2] (b) State two important items of information that could be obtained by making either a card model or computer-generated model of the storage unit. 1 … 2 … [2] (c) The shelf slots will be cut out of the uprights. Describe how CAD / CAM could be used to produce the shelf slots quickly and accurately. … … … … … … [4] (d) Fig. 12.2 shows how the two uprights slot together to produce the main part of the storage unit. 240 300 5 mm thick slot 150 mm deep Fig. 12.2 Give two benefits, other than speed, of using a scroll saw to cut out the slots. 1 … 2 … [2] (e) Fig. 12.3 shows details of one shelf and a separate edging that will be joined to the front edge of the shelf. waste edging 160 × 15 × 4 110 shelf 4 mm thick 20 Fig. 12.3 (i) Name two hand tools that could be used to produce the shelf. 1 … 2 … [2] (ii) The edging will be made from a length of acrylic. The acrylic will be heated and bent to match the curved front edge of the shelf. Explain why the acrylic would be heated in an oven rather than by a strip heater or line bender. … … … [2] (iii) The edging will be joined to the front edge using acrylic cement. Use sketches and notes to show how the edging could be held securely against the front edge of the shelf while the acrylic cement sets. [4] (iv) State one safety precaution that must be taken when using acrylic cement. … [1] (f) The items stored in the unit could be made easier to access if the unit could be made to rotate. Use sketches and notes to show how an additional base could be used to make the storage unit rotate. Give details of the materials and constructions used. [6]

25 marks

Mark scheme: 12(a) Two benefits: attractive appearance, colours available to ‘match’, resistant to moisture, easy to clean, water resistant 2 × 1 2 Accept any valid benefit Not ‘lightweight’ 12(b) Two items of information: appropriate size/dimensions, will products fit/sufficient space, appearance/aesthetics, CAD modelling allows for on-screen modelling edits including colour, ease of removal of shelves 2 × 1 2 Accept any valid item of information as a result of modelling Accept only one ref. to dimensions 12(c) CAD drawing data transferred to appropriate machine [e.g. laser cutter or equivalent CNC machine], machine parameters set, acrylic positioned on bed of machine, ‘Run’. 0–4 4 Award 0-4 dependent on technical accuracy of relevant individual points. Question Answer Marks Guidance 12(d) Two benefits of using a scroll saw: easy to control, easy to use/control/handle, thin blade, acrylic in flat position during cut and less likely to snap 2 × 1 2 Accept any valid advantage Not ‘accurate’ 12(e)(i) Two hand tools: hacksaw, coping saw, variety of files, piercing saw, tenon saw, junior hacksaw, needle files 2 × 1 2 Do not reward marking out stages 12(e)(ii) A line bender or strip heater only heats a small, specific area 1 An oven heats and softens the whole strip of acrylic 1 2 12(e)(iii) Sketch showing some form of female mould 0–2 Method of clamping across moulds in 2 directions 2 × 1 4 For maximum 2 marks each mould must ‘fit’ contour of front edge of shelf and allow for stable clamping Award 1 mark for use of G cramp or vice when curved part is glued onto the shelf [not edge] 12(e)(iv) Barrier cream, gloves for hands, mask, good ventilation. 1 12(f) Some form of additional ‘base’ 0–2 Method of rotation 0–2 Materials and constructions 0–2 6 Reward practical ideas for a base and the method of rotation

This question in 0445/32 May/June 2021

12 Fig. 12.1 shows a wall-mounted cycle rack made from mild steel. 150 backplate 3 mm thick 250 support rod Ø8 mm 600 A R25 90 Fig. 12.1 (a) State three items of research that a designer would need to consider when designing the cycle rack. 1 … 2 … 3 … [3] (b) Fig. 12.2 shows the backplate with centres marked where holes will be drilled to take the Ø8 support rods. centre for hole to be drilled 20 20 Fig. 12.2 (i) Table 12.1 shows three marking out tools that could be used to mark out the centres shown in Fig. 12.2. Complete Table 12.1 by naming the marking out tools shown. Table 12.1 Marking out tool Name of marking out tool [3] (ii) A centre punch would be used to make an indentation in the surface of the backplate so that the holes could be drilled accurately. Use sketches and notes to show a design for a jig that would locate the positions for the centre punch without the use of the marking out tools. Include the name of the material used to make the jig and state one important size. [5] (c) Fig. 12.3 shows a bending jig that could be used when bending the support rods to the shape shown at A in Fig. 12.1. Ø10 holes Ø50 mild steel rod mild steel plate 250 200 Ø10 mild steel pins Fig. 12.3 (i) Show the positions of the support rod and three Ø10 mild steel pins on Fig. 12.4, to produce bend A. Ø8 mild steel support rod Fig. 12.4 [3] (ii) State one benefit of heating the mild steel support rod before bending it to shape. … [1] (d) Fig. 12.5 shows an item of equipment that could be used when brazing the support rods to the backplate. Fig. 12.5 (i) Name the item of equipment shown in Fig. 12.5. … [1] (ii) Name two abrasives that could be used to clean the mild steel support rods before they are brazed. 1 … 2 … [2] (iii) Flux will be applied to the joints before brazing. State the purpose of the flux. … [1] (e) The cycle rack will have an applied painted finish. State two other suitable types of finish that could be applied to the cycle rack. 1 … 2 … [2] (f) Fig. 12.6 shows an exploded view of a modification to the design of the cycle rack shown in Fig. 12.1. The support rods and backplate have been replaced with 15 mm thick plywood. 70 back 15 mm thick plywood side 250 600 Ø8 mild steel rod Fig. 12.6 Fig. 12.7 shows one side of the cycle rack and a box that will be fitted to the side. The box will store items of equipment used for cycle maintenance. position of box 9 mm thick plywood box 430 × 100 × 70 Fig. 12.7 Use sketches and notes to show how the box could be fastened to the side of the cycle rack but could be removed quickly and easily to access the equipment. Include details of the materials and fittings used. [4]

25 marks

Mark scheme: 12(a) 3 items of research: type of cycle, tyre sizes, wheel diameter, weight of 3 Accept any valid items of research cycle, ease of access, where it is placed, method of attachment to wall, materials Do not reward height and length of bike 12(b)(i) Scriber, engineers square, try square, odd-leg/jenny calipers 3 12(b)(ii) ‘Plate’ or sheet with hole/s positioned accurately 1 5 Accept one whole sheet or corner jig Plate located against 1 edge 2 Plate located against 1 edge and 1 side 3 Important size: For example 250 × 150, 20 × Appropriate named material 1 20 or thickness of material for jig Important size 1 12(c)(i) 3 Award 1 mark for each correctly positioned pin 3 × 1 12(c)(ii) Heating softens the metal and makes it easier to bend, malleable 1 Accept prevents steel from ‘cracking’ 12(d)(i) Blowtorch, propane torch, gas torch, brazing torch 1 12(d)(ii) Emery cloth, wet and dry [silicon carbide paper], steel/wire wool 2 × 1 2 12(d)(iii) Flux keeps the joint clean, free from oxides, to allow the brazing rod to flow 1 12(e) Dip-coated, electroplated, plastic coated, oil/chemical blacking, powder 2 coating, galvanised 12(f) Method of attachment: use of screws/clips/magnets 0–2 4 Method enables quick removal 1 Technical accuracy: materials and fittings 1

This question in 0445/33 May/June 2022

5 Fig. 5.1 shows an electronic digital micrometer. 0.06065 Fig. 5.1 Describe one specific use for the electronic digital micrometer. … … [2]

2 marks

Mark scheme: 5 ‘Measure’ stated 1 2 Reward answers that apply the Description: e.g. diameter, thickness of object stated 1 description to a specific use: e.g. depth, thickness or length of an object

This question in 0445/32 Oct/Nov 2022

5 Fig. 5.1 shows an electrical plug with a length of electrical cable covered with plastic. electrical cable plug casing Fig. 5.1 (a) Name a specific thermoplastic that could be used to cover the electrical cable. … [1] (b) Name a specific thermosetting plastic that could be used for the plug casing. … [1] (c) State one property of plastic that makes it suitable for electrical fittings. … [1]

3 marks

Mark scheme: 5(a) PVC 1 5(b) Urea formaldehyde, ABS 1 5(c) Insulator, does not conduct electricity, easily moulded 1

This question in 0445/31 May/June 2024

11 Fig. 11.1 shows views of an incomplete design for a trophy. The trophy has three main parts made from the following materials: • front part – 5 mm thick acrylic • middle part – 2 mm thick brass • back part – 12 mm thick mahogany. 200 D&T D&T Award 2024 Award 2024 130 Fig. 11.1 (a) State two specification points a designer would have considered when designing the trophy. The trophy must: 1 … 2 … [2] (b) Fig. 11.2 shows a template that could be used to mark out the shape of one of the parts of the trophy. waste template Fig. 11.2 (i) State one benefit of using a template to mark out the shape of one of the parts of the trophy. … [1] (ii) Use sketches and notes to show how the shape could be cut out from either acrylic or mahogany and the edges made smooth. Name all the tools and equipment used. Chosen material … [4] (iii) Acrylic and brass are materials that can be self-finished. Explain what is meant by the term ‘self-finished’. … … … [2] (c) Holes will be drilled in the three parts of the trophy to allow the Ø5 rod to pass through. Give two reasons why sheet material must be clamped securely before holes are drilled through the material. 1 … 2 … [2] (d) Fig. 11.3 shows details of the caps, spacers and rod that are used to keep the three parts of the trophy held securely in position. cap Ø15 × 10 mm thick spacer Ø10 × 10 mm long screw thread rod Ø5 cap cap spacers material: aluminium Fig. 11.3 Use sketches and notes to show how the Ø5 screw thread could be cut either inside the cap or on the rod. Give details of all the tools and equipment used. [4] (e) Describe, in detail, how the words ‘D&T Award 2024’ could be engraved into the surface of the acrylic using CAD / CAM. … … … … … … [4] (f) Use sketches and notes to show a design for a base onto which the trophy could be mounted. Give details of all materials and constructions used. [4] (g) Explain why mahogany could be considered the most sustainable of the three materials used for the trophy. … … … [2]

25 marks

Mark scheme: 11(a) Any two specification points: attractive, represents D&T ‘theme’, stable as a freestanding award, title of award bold and clear, no sharp edges, fit in a person’s hand, colourful [2x1] 2 Accept any other valid points Do not accept lightweight. Do not accept durable. 11(b)(i) Speed, accuracy, easy to mark out ‘unusual’ shapes [1] 1 Accept any other valid benefits 11(b)(ii) Cut out acrylic and mahogany: Hegner saw, scroll saw, band saw, coping saw [1] Held securely: use of woodworkers, engineers vice, G cramp [1] Edges made smooth: combination of files, glasspaper, wet and dry [silicon carbide] paper [1] Quality of communication: [1] 4 Award 1 mark for ‘Held securely’ if Hegner saw, scroll saw, band saw is used to cut as this method is held by hands and is not clamped in position. 11(b)(iii) Materials that are prepared for but do not require an applied finish [1] Their appearance is enhanced by cleaning and polishing [1] 2 11(c) To prevent the sheet from ‘snagging’, spinning and cracking To prevent the underside of the sheet from splintering as the drill passes through the sheet To ensure that the hole is drilled in the correct position, accurate [2x1] 2 Accept references to personal safety Question Answer Marks Guidance 11(d) Both the cap and the rod: held in a vice [1] Die or tap named [1] Die or tap drawn [1] Technique used to cut threads [1] 4 Use of a centre lathe named only [1 mark] 11(e) Any four stages: design letters using software, transfer data to CNC machine, set up acrylic work piece in machine, set tool parameters to engrave letters [4x1] 4 Accept any valid stages. Accept imbalance between CAD and CAM. Do not reward laser cutter ‘on its own’. 11(f) Practical idea [1] Constructional details: making the ‘stand’ + joining the trophy to it [0–2] Named materials appropriate [1] 4 11(g) Mahogany trees can be replaced/replanted [1] Brass and acrylic are finite resources [1] 2

This question in 0445/33 May/June 2024