2022 MSHS S4 Prelims Paper 1 Qns_Final

Class/ Index Number / Centre Number/ ‘O’ Level Index Number / Name MARIS STELLA HIGH SCHOOL PRELIMINARY EXAMINATION SECONDARY FOUR COMPUTING 7155/01 Paper 1 Written 23 August 2022 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your class, index number, Centre number, O level index number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. Approved calculators are allowed. Answer all the 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. For Examiner’s Use This document consists of 14 printed pages. 80

2 1 Five data loss issues are shown on the left. Six possible methods of data recovery or protection are shown on the right. Draw one line to link each issue to its correct method . Data Loss Issue Method Data loss caused by hard disk head crash Anti-virus software Hacking into files and changing or deleting data Encryption A computer program that attaches itself to a harmless program and modifies it Read policy privacy An intruder with physical access to a storage device accessing files or folders Anti-spyware software Software that logs/records all key presses on your computer without you knowing Create back-up files Use of passwords and firewall [5] 2 There are five stages in developing a program. Identify three stages and elaborate the process of each stage. 1 ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… 2 ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… 3 ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… [6]

3 3 (a) Read the following section of a program code that inputs twenty numbers and then outputs the largest number input. 1 highest = 0 2 count = 0 3 while count < 20: 4 number = int ( input ( “Please enter a number: “ ) ) 5 if number < highest: 6 number = highest 7 count = count + 1 8 print ( “The highest number is “, highest ) There are three errors in this code. Locate these errors and suggest a corrected piece of code. Error 1 Line …………………….…………………….……………………………………………. Error 1 Correction ……………………………………………