SPS 2022 Sec 4E Computing Prelim P1

NAME CLASS INDEX NO. ST. PATRICK'S SCHOOL PRELIMINARY EXAMINATION 2022 SUBJECT : Computing Paper 1 (7155/01) DATE : 18 AUG 2022 LEVEL : Secondary 4 Express DURATION : 2 hours READ THESE INSTRUCTIONS FIRST Write your Name, Class and Index No. in the spaces at the top of this page. Write in dark blue or back pen. You may use an HB pencil for any diagrams or graphs. 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 Score /80 This paper contains 14 printed pages including this cover page. Candidates answer on the Question Paper.

2 1 Draw lines to match each spreadsheet function to its correct description. Function Description COUNT • • Counts the number of cells that are not empty. COUNTA • • Counts the number of characters in a cell. COUNTIF • • Counts the number of cells within a range that meet a specified condition. • Counts the number of cells that contain numeric data. [3] 2 Hendra wants to upgrade his computer by replacing its processor and memory. (a) Some of the following words need to be used to complete the description of processor and memory. bi-directional memory non-volatile gigahertz volatile temporary gigabytes storage uni-directional CPU Insert five words from the list given to complete the following statements. When the Central Processing Unit (CPU) receives an instruction to write data to the memory, the ………………………………. address bus carries the destination address from ………………………………. to ……………………………… .. . The data bus carries the data to be written. The speed of a CPU is usually measured in ………………………………. . ………………………………. memory refers to Random Access Memory. This memory is ………………………………. , which means all data and instructions stored on it are erased when the computer is switched off. [5]

3 (b) Information is stored in a computer in units known as bits and bytes. Describe what is meant by a bit and a byte. (i) Describe what is meant by a bit and a byte. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2] (ii) Convert the following amounts of data in the stated units. 139 MB = …………………………………. KB 2 450 000 000 B = …………………………………. GB [2]

4 3 Kenny works as an editor in a magazine company and uses his word processer to publish his essay. He wants to protect his data from accidental damage and malicious actions. The table has three problems that can cause loss or corruption to data. Complete the table by describing the effect of each problem. Give one method of keeping data safe from each problem. Each effect and method must be different for each problem. Problem Effect Method of keeping data safe Power failure ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. Human error ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. Computer Virus ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. ……...……………………………. [6]

5 4 (a) State and explain the main function of compilers and interpreters. …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… [2] (b) Identify two differences between a compiler and an interpreter. Difference 1: …………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… Difference 2: …………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… [4]

6 5 Identify the input(s), the output(s) and the processes required for the following problem statements: (a) To calculate the average number of hours spent travelling to work a day for a period of one month. Input(s): …………………………………….……………………………...…………… Output(s): ……………………………….……………………………………………… Processes required: …...……………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… [3] (b) To find the electrical equipment with the highest energy consumption in a month. Input(s): …………………………………….……………………………...…………… Output(s): ……………………………….……………………………………………… Processes required: …...……………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… [3]

7 6 In a “Rock Scissors Paper” game, the player inputs a choice of rock, scissors or paper. The program then generates a random choice of rock, scissors or paper. The result of the game is either a draw or a win for any one of the players depending on the outcome of the choices: • The rock wins the scissors but faces defeat against the paper. • The scissors wins the paper but faces defeat against the rock. • The paper wins the rock but faces defeat against the scissors. The player may try the game repeatedly until 0 is entered to exit. 01 move = [“Rock”, “Scissors”, “Paper”] 02 quitGame = TRUE 03 WHILE quitGame == FALSE #loop until game ends 04 OUTPUT(“Enter 1 for Rock.”) 05 OUTPUT(“Enter 2 for Scissors.”) 06 OUTPUT(“Enter 3 for Paper.”) 07 OUTPUT(“Enter 0 to exit.”) 08 INPUT user 09 IF user != 0 10 IF user < 1 or user < 3: 11 OUTPUT (“ENTER a valid choice!”) 12 CONTINUE #skips the rest of the code below and repeats at line 03 13 ENDIF 14 computer = RANDINT(1,3) 15 OUTPUT(“You picked ”, move[user - 1]) 16 OUTPUT(“Computer played”, move[computer - 1]) 17 IF computer != user 18 OUTPUT(“It is a tie!”) 19 ELSEIF computer == 1 and user == 2 20 OUTPUT(“Computer wins!”) 21 ELSEIF computer == 2 and user == 0 22 OUTPUT(“Computer wins!”) 23 ELSEIF computer == 3 and user == 1 24 OUTPUT(“Computer wins!”) 25 ELSE 26 OUTPUT(“You win!”) 27 ENDIF 28 ELSE 29 quitGame = TRUE 30 OUTPUT(“Thank you for playing, goodbye!”) 31 ENDWHILE RANDINT() is a function that generates a random number between the first and second argument provided

8 (a) There are four logic errors in the pseudo-code. State the line number of each error and write the correct pseudo-code. Error 1 ……………..…………………………………………………………………… Correction …...………….……………………………………………………………… Error 2 ……………..…………………………………………………………………… Correction …...………….……………………………………………………………… Error 3 ……………..……………………………………………………