GCSE Design and Technology Paper1

GCSE BITESIZE Examinations General Certificate of Secondary Education Design and Technology Systems and Control Technology (Electronics and Mechanisms) Specimen Paper Time Allowed: 2 Hours Maximum marks: 124 • Answer ALL questions • Mark allocations are shown in brackets • Wherever calculations are needed you should show all your working • All dimensions are given in mm unless otherwise stated • You are reminded of the need for good English and clear presentation Question 1 – Sensing circuits Electronic circuits capable of sensing temperature, light levels etc can be extremely useful when designing practical electronic products. 1a) For each of the conditions shown below state a useful product which would work by sensing that condition. (i) Temperature __________________________________ (ii) Light levels ___________________________________ (2 marks) 1b) Choose the correct electronic component from the list below to fill in the missing gaps in the statements that follow. RESISTOR LDR LED CAPACITOR THERMISTOR (i) An increase in temperature will result in less resistance to the current flowing through a _______________________ (ii) A drop in light levels will result in an increase in resistance to the current flowing through an ______________________ (2 marks) 1c) Most electronic sensing circuits are based on the principle of the potential divider. (i) Explain the meaning of the term potential divider. ____________________________________________________________________________________________________________________________________ __________________________________________________________________ (2 marks) (ii) Calculate the output voltage from the potential divider circuit shown below. (2 marks) A GCSE student is developing a moisture sensing product which will be capable of being used in a variety of applications (eg aids for the disabled, market gardening etc). The circuit diagram for the product is shown below: 1d) (i) Explain the function of the transistor (BFY51) in this circuit. ____________________________________________________________________________________________________________________________________ __________________________________________________________________ (2 marks) A partially completed PCB layout is shown below. (NB The board is viewed from its underside). (ii) Complete the layout by adding the four missing tracks and two missing pads. (3 marks) 1e) Health and Safety issues arise when producing circuit boards. Explain some of the potential hazards, and how the Health and Safety risks can be minimised. ____________________________________________________________________________________________________________________________________ __________________________________________________________________ ____________________________________________________________________________________________________________________________________ (4 marks) 1f) Explain how the industrial methods of PCB production differ from those used in school-based projects. ____________________________________________________________________________________________________________________________________ __________________________________________________________________ ____________________________________________________________________________________________________________________________________ __________________________________________________________________ (3 marks) Total for Question 1 20 marks Question 2 – Motor vehicles Motor vehicles contain a wide range of mechanisms in order to perform various required functions. Gears are used in the transmission of power from the engine to the roadwheels. A pair of meshing gears is shown in the diagram below: 2a) (i) State the name given to this type of gear system. Name of gear system __________________________________ (1 mark) (ii) From the information given calculate the gear ratio of the system. ____________________________________________________________________________________________________________________________________ __________________________________________________________________ (2 marks) For space saving reasons gears are often arranged as shown below. 2b) (i) State the name given to this type of gear system. Name of gear system ____________________________________ (1 mark) (ii) Calculate the gear ratio of this system. ____________________________________________________________________________________________________________________________________ __________________________________________________________________ ____________________________________________________________________________________________________________________________________ (5 marks) A handbrake mechanism is shown in the diagram below. 2c) (i) If an effort force of 100 Newtons is applied at Point A calculate the load force at Point B. ____________________________________________________________________________________________________________________________________ __________________________________________________________________ (3 marks) (ii) A steel cable transmits the load force to the rear brakes of the vehicle. In the space below sketch a method of attaching the steel cable to point B of this system. (3 marks) When the vehicle is stopped/parked, the hand brake needs to be able to be locked into position. 2d) Using the diagram below sketch a mechanism which will enable the handbrake lever to be locked into position. (4 marks) 2e) A windscreen wiper motor generates rotary motion which is then converted into the motion required by the wiper blades on the windscreen. (i) State the name of the type of motion which the wiper blades generate on the windscreen. Type of motion __________________________________ (2 marks) (ii) Using the diagram below sketch a mechanism which will enable the rotary motion of the motor to be converted to the required motion of the wiper blades. (3 marks) Total for Question 2 24 marks Question 3 – Child’s toy The photograph below shows a toy car designed for very young children. The toy is constructed in wood and has a paint finish applied. 3a) (i) State the name of a suitable wood/wood-based material from which the toy could be made. ________________________________________ (1 mark) (ii) State two properties required of the paint which would make it a suitable finish for use on this product. Property 1 ______________________________ Property 2 ______________________________ (2 marks) When designing toys for children it is very important to understand the needs/level of development of different age groups. Designers would therefore undertake research and analysis related to the target age group. 3b) Describe the meaning of the term research and analysis as it applies to designing. (i) Research ___________________________________________ (2 marks) (ii) Analysis ___________________________________________________ __________________________________________________________________ __________________________________________________________________ (2 marks) (iii) Name a specific research method which would be likely to yield useful information for the designers of this product. _______________________________________________________ (1 mark) The company producing the toy have decided that they wish to develop it so that it will appeal to a wider age group. They intend to enable the driver to move up and down when the toy is pushed along, and also to use a suitable plastic in the toy’s construction. 3c) In the space below sketch a suitable mechanism which will cause the driver to move up and down when the toy is pushed along. (3 marks) The new version of the toy is to be made of plastic and will be produced by a process of injection moulding. 3d) (i) Name a suitable plastic for this toy. ___________________________________________ (2 marks) (ii) State two reasons why plastic is a very good material for use in this toy. Reason 1 __________________________________ Reason 2 __________________________________ (2 marks) (iii) Describe, with the aid of a diagram, how a typical injection moulding process works. ____________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________ (4 marks) Designers and manufacturers have to balance a range of issues when developing products. 3e) Using the three headings below, explain the environmental considerations which are important at these stages of a product’s life. (i) Source of raw materials __________________________________________ __________________________________________________________________ __________________________________________________________________ (ii) Manufacturing _________________________________________________ __________________________________________________________________ __________________________________________________________________ (iii) End of use ____________________________________________________ __________________________________________________________________ __________________________________________________________________ (6 marks) Total for Question 3 25 marksQuestion 4 – Model traffic lights A local nursery wishes to raise their children’s awareness of road safety by using a set of model traffic lights. The nursery requires that the design specification for the model must include the following two requirements: 􀂃 Safe to use 􀂃 Easy for children to operate 4a) State two other specification requirements for such a model. (i) Requirement 1 _______________________________ (1 mark) (ii) Requirement 2 _______________________________ (1 mark) The nursery has asked a GCSE student to design the model. The student’s first task was to ensure that the lights would be turned on in the correct sequence ie RED -RED/AMBER -GREEN -AMBER then RED again etc. 4b) Complete the table below in order for it to be a record of the correct sequence of lights: RED AMBERGREEN1 􀁺 2 􀁺 􀁺 3 4 5 􀁺 (2 marks) The student’s first idea is that the lights could be turned on and off by using cams and microswitches as shown in the diagram below: 4c) State two advantages and two disadvantages of using such a mechanical system. (i) Advantage 1 ___________________________________ Advantage 2 ___________________________________ (2 marks) (ii) Disadvantage 1_________________________________ Disadvantage 2 _________________________________ (2 marks) The incomplete circuit diagram for the lamps and microswitches is shown below. 4d) Complete the diagram. (3 marks) After consideration the student has decided to use an electronic means of sequencing the lights. The intended system will work from 1Hz clock pulses which generate a regular sequence of 10 outputs from an IC4017. Part of the circuit diagram for the sequencer IC4017 is shown below. Note that outputs 1-4 are connected to the red lamp, output 5 to the red and amber lamps etc in order for all 10 outputs to give the full sequence of lights. 4e) (i) Name the component which is situated next to the output pins of the IC. Name of component _________________________________ (2 marks) (ii) Explain the function of this particular component in the circuit. Function of component named above _____________________________________ ___________________________________________________________________ (3 marks) 4f) On testing the circuit the student found that LEDs would work when connected to the outputs of the IC but not the lamps. (i) Explain why the lamps did not work. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (3 marks) (ii) In the space below sketch some alterations to the circuit which would be needed in order for the lamps to be driven from the IC outputs. (6 marks) Total for Question 4 25 marks Question 5 – Disco lights A disc jockey is seeking to improve the staging of his discos by positioning a set of 24v dc flashing lights at the front of his sound deck. He has decided that he will begin by having five differently coloured boxed lights as shown in the diagram below. The design of these light boxes is modular, so that more can be added when required. Each module is secured to the adjoining module by two small bolts which pass through holes drilled in the side of each box. The material used for each box is acrylic and during manufacture the fixing holes were drilled by a CAM machine. 5a) (i) Give one reason why acrylic is a suitable material for this application. Acrylic is suitable ___________________________________________________ __________________________________________________________________ (1 mark) (ii) State what you understand by the initials CAM. CAM stands for ____________________________________________________ (1 mark) (iii) Give two reasons why CAM was used for drilling the fixing holes in the side of each box. Reason 1 __________________________________________________________ Reason 2 __________________________________________________________ (2 marks) The electronic system which turns the lights on and off is driven by a PIC (Peripheral Interface Controller). 5b) (i) Explain the meaning of the term Peripheral Interface Controller. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ (2 marks) (ii) An example of a PIC is the IC16F84 which comes in an 18pin DIL package. State what you understand by the initials DIL. DIL stands for _________________________________________________ (1 mark) The IC16F84 has 13 pins which can be used as inputs or outputs, however only five outputs are required in this application (one for each of the coloured disco lights). Each output from the IC requires a suitable interface (eg relay) with its 24v coloured bulb. 5c) (i) State why such an interface is necessary. Reason ____________________________________________________________ __________________________________________________________________ (2 marks) (ii) Add a suitable interface to the diagram below for one of the outputs to the 24v bulb. (4 marks) 5d) Suggest an additional feature to the design which could be controlled by another output/outputs from the PIC. Suggestion _________________________________________________________ ____________________________________________________________________________________________________________________________________ (2 Marks) Total for Question 5 15 Marks Question 6 – Potato processing facility In order to supply a nationwide supermarket chain, a potato processing facility is being planned. The system plan below shows the main processes which the facility will need to carry out. INPUT PROCESSESOUTPUT Potatoes arrive in bulk from farms. Cleaned. Graded. Packaged. Boxed. Product is despatched to supermarket distribution centre. In order to supply the supermarkets with enough product, the scale of production will need to be very large. 6a) Explain the term “scale of production”. Scale of Production ___________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (1 mark) If this very large scale production is to be efficient the four main processes to be undertaken within the facility must be arranged in a suitable way. A floor plan of the proposed building is shown below. 6b) Indicate on the above floor plan where you think each of the four processes should be undertaken in order to achieve maximum efficiency of production. (2 marks) The potatoes will be graded into the following three general sizes: • Large (Baking Potatoes) • Medium (General Purpose) • Small (Salad Potatoes) 6c) Explain, with the aid of annotated sketches, how this grading could be achieved by mechanical means. Description ________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ (4 marks) 6d) Quality Control (QC) and Quality Assurance (QA) are needed throughout the production process. (i) Explain the meaning of these terms. Quality Control _______________________________________________________ ____________________________________________________________________ ____________________________________________________________________ (2 marks) Quality Assurance _____________________________________________________ ____________________________________________________________________ ____________________________________________________________________ (2 marks) (ii) In the space below draw a production plan for the facility which refers to the four main processes undertaken and also relevant QC and QA measures. (4 marks) Total for Question 6 15 marks