SQSS 2018 P1

2 SQSS 4E Prelim 2018 Computing 7155/01 [Turn Over COMPUTING Paper 1 Written 7155/01 17 Sep 2018 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, 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. DO NOT WRITE IN ANY BARCODES. 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. For Examiner’s Use Total 80 SHUQUN SECONDARY SCHOOL 2018 Preliminary Examination Secondary 4 Express Candidate Name: Candidate Index Number: Class: This question paper consists of 13 printed pages including the cover page.

2 SQSS 4E Prelim 2018 Computing 7155/01 [Turn Over 1 Spreadsheet software is used in many company to keep track of accounts. Draw a line between the description and the correct spreadsheet function. Description Function Returns the number of non-empty cells in the given range references ● ● COUNT ● HLOOKUP Looks for data in row and use associated data in the same row ● ● COUNTA ● CEILING Returns number rounded up to an exact multiple of significance ● ● VLOOKUP ● FLOOR [3] 2 (a) Convert the binary number 10011001 into a denary number. Show your working. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………..[2] (b) Convert the hexadecimal number C7 into a binary number. Show your working. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………..[2] (c) Convert the denary number 189 into a hexadecimal number. Show your working. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………..[2]

3 SQSS 4E Prelim 2018 Computing 7155/01 [Turn Over 3 With the advancement of technology and increasing use of online platforms, internet security is becoming more and more important to protect users from becoming victims of online crimes. (a) Pharming and phishing are examples of potential internet security issues. Explain what is meant by each of these terms. Pharming………………………………………...................................................... ……...………………………………………………………………………………….. …………………………………………………………………...…………………….. Phishing………………………………………...................................................... ……...………………………………………………………………………………….. …………………………………………………………………...………………….[4] (b) Two-factor authentication is one of the safety measures that more websites are adopting these days. Explain what is meant by Two-factor authentication. …………………………………………………………………………………………. ………………………………………………………………………………………[1] Describe one limitation of the One-Time Password (OTP) used in the system. …………………………………………………………………………………………. ………………………………………………………………………………………… ..………………………………………………………………………………….....[1]

4 SQSS 4E Prelim 2018 Computing 7155/01 [Turn Over 4 Insert five of the following words about network devices and terms used in the correct place in the text below. (a) The …………………………………… is a device responsible for modulation and demodulation. (b) The …………………………………… is the hardware interface that enables the transfer of data between a device and a network. (c) The …………………………………… is a device that forwards packets between separate networks. (d) The …………………………………… is a device that constructs a single network by connecting two similar networks together. (e) The …………………………………… is a device that transmits received packets to all connected devices. (f) The …………………………………… is a 32-byte string that identifies a wireless access point (WAP) and all devices connected to it. [6] 5 (a) State the function of the Arithmetic Logic Unit (ALU). …………………………………………………………………………………………. ……………………………………………………………………………………….[1] (b) State the function of the data bus and the address bus and also the difference between the two. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. ……………………………………………………………………………………….[3] SSID modem network hub client server network bridge router NIC

5 SQSS 4E Prelim 2018 Computing 7155/01 [Turn Over 6 (a) The two primary memory used in the computer are RAM and ROM. State what RAM and ROM represent, what each is used for, and what is the difference from each other. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. ……………………………………………………………………………………….[3] (b) Identify two types of external storage. Give an example of the storage device, state how the data is stored, the advantage and disadvantage of the storage device. Device 1 ……………………………………………………………………………….. Method ……………………………………………………………………………….... ………………………………………………………………………………………….. Advantage …………………………………………………………………………….. ………………………………………………………………………………………….. Disadvantage …………………………………………………………………………. ………………………………………………………………………………………….. Device 2 ……………………………………………………………………………….. Method ……………………………………………………………………………….... ………………………………………………………………………………………….. Advantage …………………………………………………………………………….. ………………………………………………………………………………………….. Disadvantage …………………………………………………………………………. ………………………………………………………………………………………..[4]

6 SQSS 4E Prelim 2018 Computing 7155/01 [Turn Over 7 A school PE department wishes to use a computer program to find out which Secondary One students falls in the obese category. There are 150 students altogether. State the inputs, the outputs and the processes required to find the names and the weight of the students who are obese. (Assume that the data of weight and calculated BMI is available for use.) Inputs ………………………………………………………………………………………….. ………………………………………………………………………………………………….. Outputs ………………………………………………………………………………………... ………………………………………………………………………………………………...... Processors required …………………………………………………………………………. ………………………………………………………………………………………………….. ………………………………………………………………………………………………..[6] 8 Identifiers, list and type casting are terms used in programming. Describe what is meant by : an identifier ……………………………………………………………………………………. ………………………………………………………………………………………………….. a list ……………………………………………………………………………………………. ………………………………………………………………………………………………….. Type casting ………………………………………………………………………………….. ………………………………………………………………………………………………..[3]

7 SQSS 4E Prelim 2018 Computing 7155/01 [Turn Over 9 An algorithm is required to find the addition of 20 numbers. The algorithm should stop and output “EXCEED LIMIT” and the result total if the sum of the input numbers exceeds 1000. Otherwise it will output the result total when all 20 numbers have been keyed in. Study the following pseudo-code. counter = 0 total = 1000 WHILE counter < 20 : INPUT number number + total = total IF total < 1000 OUTPUT “EXCEED LIMIT” counter = 20 ELSE counter = counter -1 ENDIF ENDWHILE OUTPUT “The total is “ + total There are four errors in this pseudo-code. Locate the errors and state the correct pseudo-code. [8] Error 1 : Correction : Error 2 : Correction : Error 3 : Correction : Error 4 : Correction :

8 Sec 4 Express Prelim 2018 Computing 7155/01 [Turn Over 10 Integers are input into the flowchart below: START Pass = 0 Fail = 0 INPUT X Is X = 0 ? Is X < 0 ? Check = X - 50 Is Check > 0? Fail = Fail +1 Pass = Pass +1 OUTPUT Pass , F