JYSS 2018 P1

JUNYUAN SECONDARY SCHOOL PRELIMINARY EXAMINATION 2018 SECONDARY FOUR EXPRESS CANDIDATE NAME CLASS INDEX NUMBER COMPUTING 7155/01 Paper 1 16 Aug 2018 Candidates answer on the Question Paper. 2 hours No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Approved calculators are allowed. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. You should show all your working. The total number of marks for this paper is 80. This document consists of 15 printed pages and 1 blank page. [Turn over For Examiner’s use

2 1 Many computer networks use the RING and STAR configurations. Compare the advantages and disadvantages of both types of networks. (a) RING Network Advantage.……….....…………................................................................................................ …............................................................................................................................................. …............................................................................................................................................. Disadvantage.……....…………................................................................................................ …............................................................................................................................................. …...................................................................................................................................... [2] (b) STAR Network Advantage.……….....…………................................................................................................ …............................................................................................................................................. …............................................................................................................................................. Disadvantage.……....…………................................................................................................ …............................................................................................................................................. …...................................................................................................................................... [2] 2 Five statements about firewalls are shown. Tick (ü) to show whether each statement is true or false. [5] Statement True (ü) False (ü) Firewalls can monitor incoming and outgoing traffic. Firewalls cannot block access to a certain website. Firewalls can be software and hardware. Firewalls can act as intermediary servers. Firewalls can block unauthorised traffic.

3 4E Computing P1 2018 Prelim [Turn over 3 Four descriptions about compilers and interpreters are shown below. Draw lines to indicate which descriptions refer to a compiler and which descriptions refer to an interpreter Description It is more difficult to debug the code since one error can produce many other associated errors. The speed of execution of program loops is slower. Compiler It produces fast, executable code that runs directly on the processor. Interpreter It is easier to debug the code since an error is displayed as soon as it is found. [4]

4 4 (a) The following pseudocode was written to input 1000 dates. 1 count = 1 2 repeat 3 input day, month, year 4 count = count + 1 5 until count = 1000 (i) Describe why the loop only inputs 999 dates instead of 1000. ……………………………………………………..……………………………………………….. …………………………………………………………………………………………..………….. ………………………………………………………………………………………………..…. [1] (ii) What needs to be changed or added to the above code to make sure 1000 dates are input? ……………………………………………………..……………………………………………….. …………………………………………………………………………………………..………….. ………………………………………………………………………………………………..…. [1] (b) Errors in code can be found using test data. Name three different types of test data. Using month from the pseudocode above, give an example of each type of test data. (i) test data type 1 …………………………………………………………………………………… ……………………………………………………………………………………………..……….. example ……………………………………………………………...…………………………… ……………………………………………………………………………………………..……….. (ii) test data type 2 …………………………………..……………………………………………… ……………………………………………………………………………………………..……….. example ……………………………………………………………...…………………………… ……………………………………………………………………………………………..……….. (iii) test data type 3 ……………………………….………………………………………………… ……………………………………………………………………………………………..……….. example ……………………………………………………………...…………………………… ……………………………………………………………………………………………..…… [6]

5 4E Computing P1 2018 Prelim [Turn over 5 This section of pseudocode asks for 80 numbers between 100 and 1000 to be entered. It checks that the numbers are in the correct range, and stores them in a list. It counts how many of the numbers are larger than 500 and then outputs the result when the program is finished. 1 Count = 0 2 FOR Index = 1 TO 80 3 INPUT 'Enter a number between 100 and 1000', Number 4 WHILE Number = 99 AND Number = 1001 5 INPUT 'This is incorrect, please try again', Number 6 ENDWHILE 7 Num[80] = Number 8 IF Number > 500 THEN Count = Count + 1 9 UNTIL Index = 80 10 PRINT Index 11 PRINT ' numbers were larger than 500' There are four lines of code that contain errors. State the line number for each error and write the correct code for that line. Error 1 Line number ............................. Correct code .............................................................................................................................. Error 2 Line number ............................. Correct code .............................................................................................................................. Error 3 Line number ............................. Correct code .............................................................................................................................. Error 4 Line number ….......................... Correct code .............................................................................................................................. [4]

6 6 (a) Complete the paragraphs choosing the correct five terms from the list. Each term can only be used once: • Ethics • Freeware • Free and Open-Source Software • Hacking • Malware • Plagiarism • Shareware • Virus Taking another person’s work from the Internet and claiming it as your own is called...................(i)........................... It is possible to protect your work online with copyright. One product that people may want to protect is software. ....................(ii)........................... does allow a person to share, copy and change software freely, but ....................(iii)......................... does not allow a person to do this legally. Software that has a licence allowing free use for a trial period is called .......................(iv)....................... . The name given to this area of Computing is ......................(v)....................... . (i) ……………………….……………………………………….. (ii) ……………………………..………………………………….. (iii) ……………