TSS 2019 P1

1 Match each of the following spreadsheet functions to the relevant data type of its output by putting a tick (√) in the box(es). Number Currency Text Date COUNTA RAND SMALL LEN [4] 2 A spreadsheet is used to record the Computing Exam results for a class of 16 students. (a) State what does the second row of the spreadsheet contain and what data type is used. …………………………………………………………………………………….. …………………………………………………………………………………. [2]

2 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. (b) State a function that allows the result in cell E3 to be calculated as the nearest whole number. …………………………………………………………………………………. [1] (c) (i) Write a formula that calculates the variance of the Total Score for the class. …………………………………………………………………………… [1] (ii) State the other function closely related to variance. …………………………………………………………………………… [1] (d) State the function that determines the most commonly obtained Total Score. …………………………………………………………………………………. [1] 3 Compare between the spreadsheet functions PMT() and PPMT(). …………………………………………………………………………………………… …………………………………………………………………………………………… ……………………………………………………………………………………….. [2] 4 Name two methods to convert denary numbers to binary numbers. …………………………………………………………………………………………… ……………………………………………………………………………………….. [2] 5 State which number system is used in ASCII codes and briefly describe how they are used. …………………………………………………………………………………………… …………………………………………………………………………………………… ……………………………………………………………………………………….. [2]

3 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. [Turn over 6 In April 2017, t he National University of Singapore (NUS) and the Nanyang Technological University (NTU) discovered a cyber -attack on their computer network. During a routine system check , malware were found hidden in the computer network. These malware had been undetected for a long period of time and it was suspected that they came from infected portable storage drives and email attachments. Cyber Security Agency (CSA) of Singapore investigated the incident and found that these malware came from oversea s with the intention to compromise government and research data. (a) Briefly describe two examples of how this cyber -attack may impact the universities negatively. (i) Negative Impact 1 ………………………………………………………… …………………………………………………………………………… [1] (ii) Negative Impact 2 ………………………………………………………… …………………………………………………………………………… [1] (b) State two possible measures to prevent this incident from occurring again. (i) Measure 1 …………………………………………………………………. …………………………………………………………………………… [1] (ii) Measure 2 …………………………………………………………………. …………………………………………………………………………… [1] 7 Distinguish between: (a) phishing and pharming, and ……………………………………………………………………………………... ……………………………………………………………………………………... ……………………………………………………………………………………... …………………………………………………………………………………. [2]

4 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. (b) a computer virus and a computer worm. ……………………………………………………………………………………... ……………………………………………………………………………………... ……………………………………………………………………………………... …………………………………………………………………………………. [2] 8 In August 2018, the Personal Data Protection Commission (PDPC) of Singapore has issued an advisory for both organizations and individuals regarding the collection of National Registration Identity Card (NRIC) number under the Personal Data Protection Act (PDPA). This advisory stated examples of whether NRIC numbers should be given by an individual to an organization: NRIC numbers should be given when you  join an organization as a new employee, or  check in to a hotel or clinic, or  subscribe to a mobile phone line. NRIC numbers should not be given when you  sign up for a retail membership, or  participate in a survey or lucky draw, or  buy movie tickets online. (a) State how an individual can easily find out whether an organization’s policy complies with the PDPA without contacting the organization. ……………………………………………………………………………………... …………………………………………………………………………………. [1] (b) A friend of yours wishes to subscribe to a new mobile phone line service by taking a photo of his National Registration Identity Card (NRIC) using his mobile phone and submitting it online. (i) Suggest a possible danger of doing so. ………………………………………………………………………………. ………………………………………………………………………………. …………………………………………………………………………… [1]

5 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. [Turn over (ii) State one advice you would give to your f riend such that he/she can subscribe to the mobile phone line service safely. ………………………………………………………………………………. …………………………………………………………………………… [1] 9 State the function of (a) a central processing unit, and …………………………………………………………………………………….. ………………………………………………………………………………… [1] (b) a computer bus. …………………………………………………………………………………….. …………………………………………………………………………………. [1] 10 There are two main differences between the RAM and the ROM. One main difference is that one is a volatile memory while the other is not. (a) State what is meant by volatile memory. …………………………………………………………………………………….. ………………………………………………………………………………… [1] (b) Describe the other main difference between RAM and ROM. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………. [1]

6 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 11 Write a Boolean statement for the figure below: ………………………………………………………………………………………... [4] 12 An alarm sounds when certain conditions occur in an artificial lake. The output X of a logic circuit that drives the alarm has a value of 1 only if: either water level (W) low and input valve (Y) off and output valve (Z) on or water level (W) high and input valve (Y) on and output valve (Z) off The inputs to the system are: Input Binary Condition W 0 Water level low 1 Water level high Y 0 Input valve off 1 Input valve on Z 0 Output valve off 1 Output valve on In the space below, draw a logic circuit for the system. [4] A B C Z

7 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. [Turn over 13 State the function of (a) a modem, and …………………………………………………………………………………….. …………………………………………………………………………………. [1] (b) a network interface card. …………………………………………………………………………………….. …………………………………………………………………………………. [1] 14 Compare between wired and wireless networks in terms of each of the following. Also state the reasons for their differences. (a) Bandwidth …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………. [2] (b) Scalability, i.e. increasing the number of connected devices. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………. [2]

8 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 15 Compare between the function and organization of the peer-to-peer network strategy versus the client-server network strategy. …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… ……………………………………………………………………………………….. [2] 16 Dr