2023 ACSBR PRELIM P1 QP

This paper has 15 pages, inclusive of the cover page. Name: Class: Index Number: Anglo-Chinese School (Barker Road) PRELIMINARY EXAMINATION 2023 SECONDARY FOUR EXPRESS COMPUTING PAPER 1 7155/01 2 HOURS INSTRUCTIONS TO CANDIDATES: Do not open this booklet until you are told to do so. Write your name and index number clearly in the spaces at the top of this page. Write in dark blue or black pen. You may use soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, 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 of question. You should show all your working. The total mark for this paper is 80. TOTAL 80

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 2 Secondary 4 Express Computing 7155/01 1 The diagram shows four types of data storage devices on the left and six descriptions of data storage on the right. Draw one or more lines from each device to its correct description(s). Device Description • Data stored is volatile Magnetic storage • • Small storage space < 10 MB Processor register • • Fastest transfer speed Random access memory (RAM) • • Secondary storage Read-only memory (ROM) • • Device has moving physical parts • Typically store terabytes of data [4]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 3 Secondary 4 Express Computing 7155/01 2 Aloysius has a computer that is assigned an Internet Protocol (IP) address. The IP v4 address is: 192.168.86.1 The IPv4 address is represented as denary values. (a) Convert the denary values 192 and 86 from the IPv4 address to 8-bit binary. 192 86 Working space [2] (b) Convert the denary value 192 into hexadecimal. Show your working. [2] (c) Aloysius’s computer is also assigned a MAC address and an IPv6 address. (i) MAC stands for [1] (ii) Identify one similarity between an IP address and a MAC address. [1] (iii) Identify one difference between an IP address and a MAC address. [1] (iv) Identify one difference between an IPv4 address and an IPv6 address. [1]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 4 Secondary 4 Express Computing 7155/01 (d) Aloysius sees the message “Set your browser to accept cookies”. (i) Explain what cookies are. [1] (ii) Explain why some websites make this request. [1]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 5 Secondary 4 Express Computing 7155/01 3 (a) The table contains statements about types of software. Tick (✓) one or more boxes in each row to indicate if the statement is true for the type of software. Statement FOSS Proprietary Public Domain Protected under copyright Can legally copy, modify and distribute Available for use at no cost Source code is usually kept secret [4] (b) Explain the difference between Creative Commons (CC) and FOSS licenses. [1] (c) Open courseware often use CC licenses. Explain what open courseware are. [1] (d) You need to use some copyrighted material in your research project. Describe two ways to avoid committing copyright infringement. [2]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 6 Secondary 4 Express Computing 7155/01 4 (a) Draw the logic circuit to represent the following Boolean statement. Do not simplify the statement. Q = A NOR (B OR C) OR (A NOR C) AND B A B C Q [4] (b) Complete the truth table for the Boolean statement. Q = A NOR (B OR C) OR (A NOR C) AND B A B C Working Space Q 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 [4] (c) Using the truth table from part ( b), state the simplified Boolean statement using a single logic gate that is equivalent to Q = A NOR (B OR C) OR (A NOR C) AND B. [1]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 7 Secondary 4 Express Computing 7155/01 5 A school uses a program to allocate subject combinations to Secondary 3 students for the next academic year. Each student can choose two elective subjects for their Secondary 3 subject combination, and they will rank their elective subject in order of preference. Depending on subject teachers’ availability, each elective subject is limited to a pre -determined maximum number of students. The program takes in the ranked choices of the students and allocates the two elective subjects based on the students’ overall results in the most recent examinations. (a) The …………………………………………. technique can be used to create smaller, more manageable parts of the program. One of these parts is results where all the students’ marks are imported into the program and the program would generate a ranked list of students based on their overall results. [1] (b) Identify and describe three other parts for this program. 1 2 3 [3] 6 Program development typically takes place in five stages. Write Code is the third stage. Identify and describe the two stages before the Write Code stage. First stage Description Second stage Description [4]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 8 Secondary 4 Express Computing 7155/01 7 Technology has enabled rapid advances in transportation all around the world. (a) Describe two economic benefits of using technology in transportation. 1 2 [2] (b) Describe one negative social impact of using technology in transportation. [1] (c) Technology is susceptible to cyberattacks. (i) Viruses and worms are types of malware. Explain what is meant by a • Virus • Worm [2] (ii) Complete the following paragraph by filling in the missing words. Viruses, worms, spyware and …………………………………………. horses are all examples of malware that need to run on a user’s computer in order to perform their respective attacks. Anti -virus and anti -spyware programs can be used to stop the malware from running. Most anti -virus and anti -spyware programs rely on a list of …………………………………………., or unique evidence, for each known version of malware. This list needs to be updated regularly through the …………………………………………. to ensure that the protection provided by these programs continues to be effective against new malware. [3]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 9 Secondary 4 Express Computing 7155/01 8 A government organisation dealing in highly classified and strategically important projects has an office housed in the basement level of a secure complex . To enhance security, the organisation implemented a separate network with no internet access and isolated from other routine governmental networks. (a) State the most appropriate network based on geographical size. [1] (b) State the network model (cl ient-server or peer-to-peer) that is most appropriate for the network used by this organisation. Give one reason why you chose this network model. [2] (c) Identify and describe the function of two network devices that could be used in the network. Device 1 Function Device 2 Function [4]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 10 Secondary 4 Express Computing 7155/01 9 A PE teacher is working on a spreadsheet to store the weight and height information and calculate the body mass index of students in his class. To test his spreadsheet, he uses some functions to generate random test data for weight in integer and height in float. An example from the s