St. Catherine s High School Annual June 2015 Class: Senior 4 Subject: Computer Studies Total: Duration: 2 hrs Final Total: /100 MAKE SURE TO CHECK THAT YOU ARE GIVEN FIVE PRINTED PAGES Calculators may NOT be used. Answer all the questions on a separate paper. Question 1 Choose ONE correct answer for each of the below: a) A medium for transferring data between two locations is called a: i. Network ii. Communications channel iii. Modem iv. Bus b) A sizeable geographical area with digital communication based on the telephone system is called a: i. LAN ii. WAN iii. Modulator-Demodulator iv. All of the above c) A file containing relatively permanent data is a: i. Random file ii. Transaction file iii. Master file iv. Sequential file d) Accessing records from a file without searching from the beginning of the file is: i. Time sharing ii. Random iii. Direct access iv. Access time e) An input device which can read characters directly from an ordinary piece of paper is: i. OCR ii. OMR iii. MSI Ms Charlene Ellul Page 1 of 5
iv. CRT f) A compiler is: i. A person who compiles source programs ii. The same thing as a programmer iii. A data input operator iv. A program which translates source code to object code g) A method for sending data from one place to another by physical or electronic means is: i. Email ii. Internet iii. Data transmission iv. Distributed processing h) What is meant by embedded system? i. A system designed for specific control functions within a larger system ii. A system which is assigned one and only one task iii. A system which uses one kind of software iv. A system meant for applications only i) A computer uses to convert digital signals from a computer into analogue signals, and vice versa: i. Multiplexer ii. Demodulator iii. Modem iv. Decoder [9] Total Question 1: 9 marks Question 2 a) What is an algorithm? [1] b) Distinguish between source code and executable code. [2] c) Name THREE types of programming errors and give an example of each. [6] d) Study the program below, which is supposed to display a mathematical table from 1 to 12 and then answer the questions: Ms Charlene Ellul Page 2 of 5
i. What is the concept found in line 3 called? ii. The program uses one type of iteration, mention another one used in Java. iii. As it is the program has an error. In which line number is this error? iv. Fix the error found in (iii) so that the program works as intended. v. Fill in Line 8 so that the program displays the answer. [5] e) Name TWO conditional statements used in Java. [2] f) Choose TWO looping structures found in Java and show by writing a short program how they are used to display the numbers from 1 to 10. [6] g) Why does source code needs to be translated? [1] h) The program below finds the total of 3 test marks ad their average is then displayed on the screen. Find ONE syntax, ONE logical and ONE runtime error. Give reasons for your answers. class Test{ public static void main (String args[]){ int mark1 = 50; int mark2 = 35; int mark3 = 60; int marks = 0; double total = mark1+mark2-mark3; double average = total/marks; System.out.println( The average is:); System.out.println(average); } } [6] i) From the program given in h) find a reserved word and the name of the class. [2] Total Question 2: 30 marks Ms Charlene Ellul Page 3 of 5
Question 3 a) Different data processing environments require different operating systems. Realtime, batch and time-sharing are three types of operating systems. For each type give an example where it is best used. [3] b) Two other types of operating systems are single-user and multi-user. Briefly explain the difference between them. [2] c) Two types of interfaces in operating systems are CLI and GUI. What do the acronyms CLI and GUI stand for? [2] d) For each situation below name the most suitable operating system: i. Payroll system. ii. Aircraft control systems. iii. Banking system. [3] e) Briefly describe what a utility software is. [2] f) State which utility software performs the function described below: i. This reduces the size of data in order to save space. ii. This utility reduces data access time and allows storage to be used more efficiently. iii. This checks your hard disk for errors and corrects problems found. [3] g) Real time operating systems is an operating system widely used in different circumstances. i. Give an example of where time critical real-time operating system may be used. ii. Give the criteria for a system to be real-time. iii. Give three characteristics of a real-time system. [5] Total Question 3: 20 marks Question 4 a) Define the terms LAN, MAN and WAN. [3] b) E-mail is an application used in WAN. Give another example of a use for WAN and another for LAN. [2] c) Search engine, home page, URL (uniform resource locator), hypertext and FTP (file transfer protocol) are all terms concerned with web browsers. Briefly define the five terms. [5] d) Give an advantage of LAN over standalone computer. [1] e) What is a topology? [1] f) Name THREE types of topologies. [3] g) For each of the topologies mentioned in f) draw their diagram. [6] h) For each of the topologies mentioned in f) state TWO advantages and TWO disadvantages. [12] i) Which is the fastest communication medium used to date? Explain how it works. [2] Ms Charlene Ellul Page 4 of 5
j) Mention ONE wireless communication medium. [2] Total Question 4: 37 marks Question 5 a) Indicate whether the following are System Software or Application Software. The first one has been done to help you. [2] b) Give two differences between Tailor-Made and Off-The-Shelf packages. [2] Total Question 5: 4 marks Ms Charlene Ellul Page 5 of 5