NASS S4 2022 Prelim P1

Name: ............................................................................ Register no: ............. Class: ............... NGEE ANN SECONDARY SCHOOL O PRELIMINARY EXAMINATION COMPUTING 7155/01 Paper 1 Written 25 August 2022 2 hours Candidates answer on the Question Paper. No Additional Materials are required. Instructions to Candidates Write your name, register number and class at the top of this page. Answer ALL questions. Write in dark blue or black pen. You may use pencil for any diagrams, graphs, tables or rough working. The use of an approved scientific calculator is expected, where appropriate. 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. Checked by student: _____________________ Date: ______________ This document consists of 16 printed pages and 2 blank pages. For Examiner’s Use Total /80

2 NAS/2022/PRELIM/4E/COMPUTING(7155/01) 1 (a) The bus topology and the star topology are two possible physical layouts of a network. Give one feature that is the same for both a bus topology and a star topology, and one difference between the two. Feature that is the same: …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. Difference: …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2] (b) A home network typically requires a network interface controller and a router. Identify and describe the function of one other network device that could be part of the home network. Device: ……….………………………………………. Function: …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2]

3 NAS/2022/PRELIM/4E/COMPUTING(7155/01) 2 Ms Anna attempts to use a spreadsheet to record the gender ratio of each class. She records: • the number of girls and boys in each class • the ratio of girls to boys in each class • the classes Upon keying the ratio from cells C2 to C4, the spreadsheet detects the input and automatically changes the data type into something other than the expected ratio. (a) Identify the data type which cells C2 to C4 are changed into. …………………………………………………………………………………….. [1] (b) Describe how Ms Anna can make the spreadsheet display the expected ratio. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2] (c) Cell D2 needs to show the percentage of girls in each class. Identify the most appropriate function that will need to be entered into D2 and copied to cells D3 and D4. …………………………………………………………………………………….. [1] (d) Cell E6 needs to show a boolean value which indicates if the number of boys in class A is more than the number of girls in class A and more than the combined total number of boys from the other two classes. Identify the most appropriate function that will need to be entered into E6. …………………………………………………………………………………….. [2]

4 NAS/2022/PRELIM/4E/COMPUTING(7155/01) (e) Cell E7 needs to show the class with most number of girls. Identify the most appropriate function that will need to be entered into E7. …………………………………………………………………………………….. [2] 3 Devon is developing a single-player computer game. The objective of the game is to harvest as many crops as possible within a time limit in order to score the most number of points possible. The player is able to customise the look of the sprite, and buy any to ols that can help to speed up the process of harvesting before the start of the game using the points the player has accumulated. The game will save the points achieved by the player after every round. Before the program is written, Devon decomposes the problem using a modular approach. (a) Describe what is meant by a modular approach. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2] (b) One of the modules is to save the points achieved by the player after each round. Identify three other modules that can be decomposed from the problem. Module 1: …………………………………………………………………………………….. …………………………………………………………………………………….. Module 2: …………………………………………………………………………………….. …………………………………………………………………………………….. Module 3: …………………………………………………………………………………….. …………………………………………………………………………………….. [3]

5 NAS/2022/PRELIM/4E/COMPUTING(7155/01) (c) Devon eventually completes writing the code as well as testing and refining the code. Describe the remaining stage of program development that is necessary for him to complete the program development. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2] 4 A local bank has recently developed a mobile application that allows its users to make digital payments by scanning a QR code when shopping overseas. The user can review the price in either currency before confirming payment. (a) State and explain one positive impact that this mobile application may have on businesses. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [1] (b) Transaction data from payment applications could be analysed further with Artificial Intelligence (AI) to benefit the user. Describe how transaction data from such a mobile application can be analysed further with AI. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2] (c) Payment using mobile application is often accompanied with biometric authentication. Explain the benefit of using biometric authentication when making payment. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2]

6 NAS/2022/PRELIM/4E/COMPUTING(7155/01) 5 A ransomware attack typically works by tricking a target into clicking a malicious link by using a fake email that appears to be from reputable companies. (a) State another form of cyberattack which works in a similar way. …………………………………………………………………………………….. [1] (b) Once the attackers have access to critical files on the computer, they will encrypt the files and render the files inaccessible to the owners, unless a ransom is paid. Define the term encryption. …………………………………………………………………………………….. …………………………………………………………………………………….. [1] (c) Suggest one method to prevent the occurrence of ransomware attacks. …………………………………………………………………………………….. …………………………………………………………………………………….. [1] 6 Match each of the following types of hardware to its purpose. Hardware Purpose Address bus • • to send address information is sent from memory to processor. • to send address information from processor to memory. Data bus • • to send data between processor and memory • allows users to enter data and instructions into a computer Input device • • to display, project or print processes data from a computer • follows instructions and decides when data should be stored, received or transmitted Control unit • • part of the compu