SRSS 2020 P1

This question paper consists of 14 printed pages including the cover page. [Turn over SERANGOON SECONDARY SCHOOL PRELIMINARY EXAMINATION SECONDARY 4 EXPRESS CANDIDATE NAME ( ) CLASS CENTRE NUMBER S INDEX NUMBER COMPUTING 7155/01 Paper 1 25 August 2020 2 hours Setter(s): Mr Adrial Tan READ THESE INSTRUCTIONS FIRST Write you Centre number, index number and name 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, graphs or rough working. Do not use staples, paper clips, 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 question. You should show all your working. The total number of marks for this paper is 80. For Examiner’s Use 80

2 1 (a) The diagram below shows four logic gates on the left and three sets of Boolean values on the right. The Boolean values have been extracted from the truth tables of logic gates. Draw one line from each logic gate to the correct set of Boolean values. Each set of Boolean values may have more than one logic gate matched to it. Logic gates Boolean Values [4] A B X 0 0 1 0 1 1 A B X 0 0 0 1 1 1 A B X 0 1 0 1 1 0 A A A A B B B B X X X X

3 (b) Draw a logic circuit to represent the following Boolean statement. Do not simplify the statement. X = (A OR (NOT B NAND C)) AND (A NOR B) [5] (c) Complete the truth table for the Boolean statement: X = (A OR (NOT B NAND C)) AND (A NOR B) A B C Working Space X 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] A B C X

4 2 Insert five of the following word(s) about network devices and terms used in the correct place in the text below. DHCP server firewall LAN cable modem network hub network interface card network switch router (a) The ……………………………………..… is the hardware interface that enables the transfer of data between a device and a network. (b) The ……………………………………..… is a device that constructs a single network by connecting two similar networks together. (c) The ……………………………………..… is a device responsible for modulating and demodulating digital data when data is transmitted over long distances. (d) The ……………………………………..… is a device that forwards packets between separate networks. (e) The ……………………………………..… is a device that transmits received packets to all connected devices. [5] 3 During the outbreak of COVID-19 pandemic, countries all over the world went into lockdowns. Technology was extensively used to minimise the impact on the everyday lives of people. (a) Give two social and two economic benefits that technology has brought about on the everyday lives of people during the lockdowns. Social benefit 1 …………………………………………………………………………. ……………………………………………………………………………………………. Social benefit 2 ……………………