AQA Level 3 Technical Level IT: PROGRAMMING Unit 2 Computer programming | QUESTIONS ONLY

Level 3 Technical Level IT: PROGRAMMING Unit 2 Computer programming Monday 13 May 2019 Morning Time allowed: 2 hours Materials For this paper you must have: • a ruler • a scientific calculator (non-programmable) • stencils or other drawing equipment (eg flowchart stencils). Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the top of this page. • Answer all questions. • You must answer each question in the space provided. Do not write outside the box around each page or on blank pages. • Do all rough work in this book. Cross through any work you do not want to be marked. • If you need more space use the additional pages at the back of this booklet. Information • The marks for questions are shown in brackets. • The maximum mark for this paper is 80. • There are 50 marks in Section A and 30 marks in Section B. Both sections should be attempted. Advice • In all calculations, show clearly how you work out your answer. • Use diagrams, where appropriate, to clarify your answers. • You are expected to use a calculator where appropriate. • You are reminded of the need for good English and clear presentation in your answers. Section A Answer all questions in this section. outside the box 0 1 What does the flowchart symbol in Figure 1 represent? Tick () one box. [1 mark] Figure 1 Decision Input Process Sequence 0 2 Which statement describes a pointer in computer programming? Tick () one box. [1 mark] A pointer is an output device such as a printer. A pointer performs mathematical and logical operations. A pointer references a location in memory. A pointer stores the next instruction to be processed. 0 3 In application design, ‘familiarity’ means Tick () one box. [1 mark] a preference for a particular type of hardware. comparable in appearance to existing software. configuring software with a user’s preferences. software which is compatible with the previous version. 0 4 In software engineering, the abstraction principle is the Tick () one box. [1 mark] aim of reducing duplication of information in a program. principle of software versioning which identifies variations. use of a single symbol to represent different types. wrapping up of data into a single unit or class. Turn over for the next question Turn over ► enables a website owner to hide source code from the end user. box is generated on the user’s local computer system. is run directly in a web browser. Describe the difference between assembly language and machine code. [3 marks] box Explain how a recursive function works. Give an example in your answer. [4 marks] Turn over for the next question Turn over ► Describe two disadvantages of the agile development approach. [4 marks] box Describe the meaning of the ‘single responsibility principle’. [2 marks] Turn over for the next question box *07* Turn over ► Software testing is used to ensure that business systems and product features behave as expected. box Explain the principles of workflow testing. [4 marks] *0* Turn over for the next question DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box Turn over ► The number of rolls of wallpaper needed to cover a wall is worked out by: (width of wall × height of wall) ÷ 4.5 Develop an algorithm using pseudocode that allows a decorator to calculate the number of rolls of wallpaper needed for a room. The algorithm should: • prompt the user to enter the number of walls • prompt the user to enter the different width and height for each wall • calculate the number of rolls of wallpaper needed • output the number of rolls needed for the room. box There are no marks available for validating inputs. [8 marks] box Turn over for the next question Turn over ► User documentation describes how to use features of a piece of software. Discuss what makes good user documentation. [6 marks] box Turn over for the next question DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box Turn over ► Figure 2 shows some code, written in Python, for a simple maths quiz. Suggest ways in which the code in Figure 2 could be improved. For each suggestion explain how it improves the code. [8 marks] box Figure 2 01 a=0 02 b=0 03 c=0 04 name=input('Welcome to the Maths quiz! What is your name? ') 05 print('Hello',name,', let us get started! ') 06 print('Question 1') 07 q1=input('Let us start easy. What is the smallest prime number? ') 08 if q1=='2': 09 a=int(1) 10 print('Question 2') 11 q2=input('What is the value of pi to 2 decimal places? ') 12 if q2=='3.14': 13 b=int(1) 14 print('Question 3') 15 q3=input('What is (8 × 7 – 6) ÷ 5? ') 16 if q3=='10': 17 c=int(1) 18 score=str(a+b+c) 19 print('You got',score,'out of 3') box Turn over for Section B Turn over ► Section B Answer all questions in this section. box . Two techniques used to test software are ‘white box testing’ and ‘black box testing’. Discuss the differences between white box testing and black box testing. [9 marks] box 1 5 . 2 A trace table is one method used to identify bugs in a program. Describe three other methods used to debug programs. [6 marks] 1 2 3 Turn over for the next question *17* Turn over ► Figure 3 is a recipe for lemon curd. Figure 3 box Lemon Curd Lemon curd is made by heating the ingredients in a bowl over a pan of hot water. Ingredients You will need 3 lemons Bowl 1 (to beat the eggs in) 250 g butter Bowl 2 (to heat all the ingredients in) 500 g sugar Pan of hot water 2 eggs Three jars Method 1. Beat the eggs in Bowl 1. 2. Grate the rind off the lemons into Bowl 1. 3. Squeeze the juice of the lemons into Bowl 1. 4. Weigh the correct amount of butter and sugar. 5. Add the sugar to Bowl 1. 6. Place Bowl 2 over the pan of hot water. 7. Melt the butter in Bowl 2. 8. Add the contents of Bowl 1 to the melted butter in Bowl 2. 9. Stir until mixture thickens. 10. Turn off the heat and allow mixture to cool. 11. Pour into three jars. Note that ‘rind’ is the outer skin of a lemon. Develop an algorithm using a flowchart to make lemon curd. [15 marks] *1* Extra space is available on the next page if required Turn over ► END OF QUESTIONS If needed, use the following pages to continue your answers. Write the question number beside your answer. box Turn over ► box There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box Copyright information For confidentiality purposes, from the November 2015 examination series, acknowledgements of third-party copyright material are published in a separate booklet rather than including them on the examination paper or support materials. This booklet is published after each examination series and is available for free download from after the live examination series. Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright-holders may have been unsuccessful and AQA will be happy to rectify any omissions of acknowledgements. If you have any queries please contact the Copyright Team, AQA, Stag Hill House, Guildford, GU2 7XJ. 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