2021 BVSS Computing P1

Bukit View Secondary School Secondary 4 Express Preliminary Examination 2021 BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL SCHOOL CANDIDATE NAME CLASS INDEX NUMBER Computing 7155/01 Paper 1 15 September 2021 2 hours Candidates answer on the Question Paper. READ THESE INSTRUCTIONS FIRST Write your name, class and index number on the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Approved calculators are allowed. 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. You should show all your working. The maximum number of marks is 80. For Examiner’s use Marks 80 Setter: Ms Lee Poh Tin Parent's Signature:__________________ This question paper consists of 15 printed pages and 1 blank page.

2 1 (a) Draw a line between the description and the correct stage in developing a program. Description Stage Gather requirements Train users to use the program. Plan solutions Compare the actual output with expected output. Write code Determine the complete set of outputs that is necessary to solve the problem. Test and refine code Write possible algorithms using either flowcharts or pseudo-code. Implement code [4] (b) A program may use constants, variables and arrays. Describe an array. Give an example to explain the advantage of using arrays. Description …………………………………………………………………….... ……………………………………………………………………..………..……. Example ………………………………………………………………………... ……………………………………………………………………..………..……. [2]

3 2 A Local Area Network (LAN) is a network of computing devices connected within a small geographical area. (a) A LAN can have both wired and wireless connections. (i) Give an advantage of using wired connection. …………………………………………………………………………… …………………………………………………………………………… [1] (ii) Give an advantage of using wireless connection. …………………………………………………………………………… …………………………………………………………………………… [1] (b) Identify and describe the function of two network devices that could be used in a LAN. Component 1 …………………………………………………………………… Description ……………………………………………………………………... ……………………………………………………………………..………..……. ……………………………………………………………………..………..……. Component 2 …………………………………………………………………… Description ……………………………………………………………………... ……………………………………………………………………..………..……. ……………………………………………………………………..………..……. [4]

4 3 Memory is the part of the computer that stores data. (a) Convert 1810 KiB of memory to bytes. …………………………………………………………………………………… …………………………………………………………………………………… [1] (b) Convert 60416 MiB to GiB. …………………………………………………………………………………… …………………………………………………………………………………… [1] (c) In an image file, 16 bits are used to represent each pixel of the image. The image file has 6144 pixels. Calculate the size of the image file in bytes. …………………………………………………………………………………… …………………………………………………………………………………… [1] (d) Memory can be volatile or non-volatile. Give an example of volatile memory and an example of non-volatile memory. Volatile memory ………………………………..………………….………… Non-volatile memory ………………………………..………………….…… [2]

5 4 A class of 20 students have taken their temperatures. For students who have temperature 38 degrees celsius or above, the Form Teacher needs to report their records to the school office. (a) State the inputs. …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… [1] (b) State the outputs. …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… [1] (c) Describe the processes required. …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… [1]

6 5 Data bus and address bus are components of a computer. (a) State the function of the address bus. …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… [1] (b) State the function of the data bus. …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… [1] 6 Name the type of cyberattacks described in the table below. Description Type of cyberattack A computer program that attaches itself to a normally harmless program and modifies it. A computer program that pretends to be a harmless file or useful application but it can cause unauthorised access to the computer. A computer program that runs automatically and attempts to spread by sending copies of itself to other computers. A small piece of data used by websites to store personal information on a user’s web browser. [4]

7 7 (a) Explain how the binary number 11010111 is converted into a denary number. …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… [2] (b) Hexadecimal RGB codes represent colours. (i) E9A4B8 is an example of a hexadecimal RGB code. Complete the table to convert each hexadecimal digit to its 4-bit binary value. RGB code E 9 A 4 B 8 4-bit binary ………… ………… ………… ………… ………… ………… [3] (ii) RGB colours comprise of Red, Green and Blue values. The Green value of one colour is 211 in denary. Convert 211 into hexadecimal. …………………………………………………………………………… [1] (iii) RGB codes are one example of where hexadecimal is used to represent binary. State two other examples where hexadecimal is used to represent binary. 1 ………………………………………………………………………… 2 ………………………………………………………………………… [2]

8 8 The pseudo-code below inputs data on name, mass and height. The predefined function round(x, 0) will return the nearest whole number for x. For example, round(19.79, 0) will return 20; and round(19.79, 1) will return 19.8. max = 0 FOR i = 0 to 2 INPUT name, mass, height bmi = round(mass / (height * height), 1) IF bmi > max max = bmi person = name ENDIF NEXT OUTPUT person, round(max,0) (a) Complete the trace table for this pseudo-code using the following test data. ALI, 52.5, 1.6, SARAH, 49, 1.5, TOMMY, 63.5, 1.8 i name mass height bmi max person OUTPUT [5]

9 (b) Data validation is a process of ensuring that the input data satisfies a set of requirements. Range check is a data validation which checks that value entered is between an upper val