JYSS 2020 Computing P1 Solution

Mark Scheme – 2020 Sec 4E Computing Prelim Paper 1 Qn Answer Marks 1(a) One mark for each correct answer Application Storage Medium Storage of a text book in electronic form CD-ROM Storage of photographs in a mobile phone flash memory A offline backup of a complete PC file system external hard disk Storage of operating system and applications software internal hard disk Playback of video files DVD 5 1(b) (i) flash memory card 1 1(b) (ii) Any two from: • faster access time than magnetic or optical external storage • not vulnerable to drops, mechanical shocks, scratches or fingerprints • more robust / no moving parts • physically small and lighter in weight • low energy consumption • low heat generation 2

2 Qn Answer Marks 2 One mark for each correct line, each box must have only one connection. Network term Description Wired network A component that receives and forwards data packets using IP addressing Wireless network A combination of computers and components that are only connected using cables Bridge An internal component that allows a computer to connect to a network Router A combination of computers and components that are only connected using radio waves Network Interface Card (NIC) A combination of computing devices covering a large-scale geographical area Wide area network (WAN) A component that joins similar networks together 6

3 4E Computing P1 2020 Prelim [Turn over Qn Answer Marks 3(a) One mark for each correct 8-bit binary number 67 0 1 0 0 0 0 1 1 65 0 1 0 0 0 0 0 1 82 0 1 0 1 0 0 1 0 3 3(b) One mark for each correct hexadecimal number 0101 0000 50 0100 0101 45 0100 1110 4E 3 Qn Answer Marks 4 One mark for each correct point Inputs 200 books’ titles 200 corresponding number of copies of books sold Outputs Title of the best-selling book Corresponding number of copies sold Processes Store the data in lists Search for the book with the greatest number sold 6

4 Qn Answer Marks 5 The technique of decomposition is a method of breaking down a complex problem or process into smaller parts such that each part is more manageable and easier to understand. The technique of pattern recognition is a method of identifying similarities among two or more items. The technique of generalisation is a method of replacing two or more similar items with a single, more common item. 5

5 4E Computing P1 2020 Prelim [Turn over Qn Answer Marks 6(a) One mark for each correct gate, with the correct input(s) 4 6(b) Four marks for 8 correct outputs Three marks for 6 or 7 correct outputs Two marks for 4 or 5 correct outputs One mark for 2 or 3 correct outputs Input Working space Output A B C D E F X 0 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 0 0 1 1 1 0 1 1 0 0 0 0 1 0 0 0 1 0 0 1 0 1 0 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0 0 0 4 A B X C D E F

6 Qn Answer Marks 7