Cambridge IGCSE Computer Studies 0420 — 2010 May/June Paper 1 · Variant 3

This document consists of 19 printed pages and 1 blank page. IB10 06_0420_13/RP © UCLES 2010 [Turn over *0356289971* For Examiner's Use UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMPUTER STUDIES 0420/13 Paper 1 May/June 2010 2 hours 30 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. No marks will be awarded for using brand names of software packages or hardware. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. www.XtremePapers.com

2 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 1 Explain, with examples where appropriate, the following five computer terms. (a) buffer [2] (b) batch processing [2] (c) e-commerce [2] (d) simulation [2] (e) email [2]

3 © UCLES 2010 0420/13/M/J/10 [Turn over For Examiner's Use 2 A company making televisions has introduced robots to replace the human work force. (a) Describe three effects this would have on the work force. 1 2 3 [3] (b) Give two advantages to the company of introducing robots. 1 2 [2] (c) How could the robots be trained to assemble the televisions? [1] (d) A whole batch of televisions was produced with some of the parts missing. How could this error have been avoided? [1]

4 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 3 State four tasks performed at the analysis stage in systems analysis. 1 2 3 4 [4] 4 Give four features of a Data Protection Act. 1 2 3 4 [4]

5 © UCLES 2010 0420/13/M/J/10 [Turn over For Examiner's Use 5 A bank is worried about computer crime. One of their concerns is online access to customer accounts. (a) How can a customer’s access details be discovered by criminals? [2] (b) Why would a customer using a credit card for online shopping be more of a security risk than a customer using the same card in a shop? [2] (c) Describe what measures the bank can take to safeguard customer accounts. [2]

6 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 6 An expert system is being developed to help engineers diagnose faults in aero engines. (a) Describe the steps taken to develop this new expert system. [4] (b) Another method used to identify and rectify faults is to train engineers using virtual reality systems. (i) What is virtual reality? [1] (ii) What special hardware is used to interface with virtual reality systems? [1]

7 © UCLES 2010 0420/13/M/J/10 [Turn over For Examiner's Use 7 A screen has been developed to allow the input of data into the following fields: name, sex, address, date of birth and examination results. (a) A first attempt at designing the screen is shown below: This is not a very good input screen. Give four ways in which it could be improved. 1 2 3 4 [4] (b) (i) What is verification? (ii) Which fields should be verified? [3] Student Records Student name: ………………………………….. Sex: …………………… Student address: ……………………………………………………………… ……………………………………………………………………………………. Date of birth: ……… / ……… / ……… Exam results: Subjects and Grades Type in NEXT to go to next student or BACK to go to previous student: …………………………

8 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 8 A supermarket makes use of barcodes on all its goods as part of its automatic stock control system. (a) Describe how the price is found for each item sold. [2] (b) The following are steps in the automatic stock control system. Number the steps in the correct order. if stock level ≤ minimum stock level report printed out for the manager stock level reduced by 1 new stock value written back to file more items are ordered automatically [4] 9 A factory uses a computer system to store information about customers, spare parts and general administration. (a) Spare parts can be identified by selecting from diagrams on a computer screen. Describe what hardware would be needed to allow the parts to be selected in this way. [2]

9 © UCLES 2010 0420/13/M/J/10 [Turn over For Examiner's Use (b) The factory needs to buy a new printer. It has decided to buy either a dot matrix printer or an inkjet printer. Discuss the advantages and disadvantages of using both types of printer in this application. Dot matrix printer: Advantages Disadvantages [3] Inkjet printer: Advantages Disadvantages [3]

10 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 10 A small company runs six cars in its fleet. They have produced a spreadsheet to compare running costs over a five month period: (a) It was decided to print out the spreadsheet formulas from D2 to E8. Using the grid below, show what formulas would be printed: D E 1 Total cost ($) Average cost per month ($) 2 3 4 5 6 7 8 [4] A B C D E 1 Car Identity Total number of km Cost per km ($) Total cost ($) Average cost per month ($) 2 10001 30 000 1.00 30 000 6 000 3 10002 20 000 4.00 80 000 16 000 4 10003 50 000 1.50 75 000 15 000 5 10004 30 000 2.00 60 000 12 000 6 10005 20 000 2.50 50 000 10 000 7 10006 30 000 1.50 45 000 9 000 8 Averages: 2.08 56 667 11 333

11 © UCLES 2010 0420/13/M/J/10 [Turn over For Examiner's Use (b) A graph of Cost per km ($) was drawn: 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 10001 10002 10003 10004 Car identity Cost per km ($) Cost per km ($) 10005 10006 (i) Which cells were highlighted to produce this graph? [2] (ii) Describe how the average value of 2.08 would be shown on the graph. [1] (c) The data in cell C6 was changed to 3.00. Which cells would be updated automatically? [2]

12 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 11 A database has been set up showing information about cars: Car ref No of doors Engine (litres) CO2 (g/km) Fuel used (km/litre) No of cylinders A 3 1.4 145 15.3 4 B 4 2.0 193 12.3 4 C 5 2.5 231 10.9 6 D 3 2.0 190 11.2 6 E 4 1.3 120 17.5 4 F 5 1.8 180 14.6 4 G 4 3.0 240 9.5 6 H 4 1.2 115 19.7 3 (a) Using Car ref only, write down which cars would be output if the following search condition was used: (No of doors = 4) AND (Fuel used (km/litre) > 15) [2] (b) Write down a search condition to find out which cars have engines larger than 1.8 litres OR have CO2 emissions higher than 150 g/km. [2] (c) The database is sorted in ascending order on Fuel used (km/litre). Using Car ref only, write down the results of the sort. [2]

13 © UCLES 2010 0420/13/M/J/10 [Turn over For Examiner's Use 12 (a) State two items of hardware needed to enable a standard computer system to take part in video conferencing. 1 2 [2] (b) State two additional items of software that would be needed for the video conferencing to take place. 1 2 [2] (c) Describe two potential problems when using video conferencing. 1 2 [2]

14 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 13 Study the following flowchart very carefully: START STOP PRINT N INPUT X T = X Is X = 0? N = 1 T = T/10 Is T < 10? N = N + 1 No Yes STOP PRINT “error” Yes No What output would you expect if the following data was input into the flowchart? X OUTPUT -150 540 0 [3]

15 © UCLES 2010 0420/13/M/J/10 [Turn over For Examiner's Use 14 A safety system has been developed to stop vehicles getting too close to each other on the road. A B sensors If vehicle A gets too close to vehicle B, the brakes are automatically applied by a computer system in vehicle A. (a) What type of sensors could be used on the vehicles? [1] (b) Describe what the safety system does to constantly monitor how close the vehicle is to the vehicles in front and decide when to take action. [4] (c) Describe two potential problems with this safety system. 1 2 [2]

16 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 15 A floor turtle can use the following instructions: Instruction Meaning FORWARD d Move d cm forward BACKWARD d Move d cm backward LEFT t Turn left t degrees RIGHT t Turn right t degrees REPEAT n Repeat the next set of instructions n times ENDREPEAT End of REPEAT loop PENUP Raise the pen PENDOWN Lower the pen (In the following grid, each square is 10 cm by 10 cm.) Start End

17 © UCLES 2010 0420/13/M/J/10 [Turn over For Examiner's Use Complete the set of instructions to draw the shape (shown in bold lines) by filling in the blank lines. LEFT 90 PENDOWN FORWARD 10 RIGHT 90 [5]

18 © UCLES 2010 0420/13/M/J/10 For Examiner's Use 16 (a) Write an algorithm, using pseudocode or a flowchart, which:
inputs 50 numbers
outputs how many of the numbers were > 100 [3]

19 © UCLES 2010 0420/13/M/J/10 For Examiner's Use (b) Write an algorithm, using pseudocode or a flowchart, which:
inputs 100 numbers
finds the average of the input numbers
outputs the average [3]

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