Download computer science master program entrance exam and more Exams Programming Languages in PDF only on Docsity! Department of Computer Science Faculty of Informatics Addis Ababa University Entrance Examination for the M. Sc. Program in Computer Science Date: July 13, 2007 Time allowed: 3 hours Name: Instructions 1. Read the instructions and the questions carefully. 2. Write your name only on this page. Writing your name on the other pages will automatically disqualify you from this exam. 3. Answer all questions eligibly on the spaces provided on the question papers. Please make sure that sentences are short, and grammatically and logically correct. You can use the back side of each paper when space is not sufficient. In such a case, please indicate so. 4. This examination booklet consists of 11 pages (excluding this cover page). Make sure that the question papers are numbered consecutively (at the bottom of each page) and that no question papers are missing or replicated. 5. Cheating is strictly prohibited. Any person found cheating will be automatically disqualified from the exam. 6. Use only the rough papers provided. Using other unauthorized papers will be considered as cheating. 7. Switch off your mobile phones. You are not allowed to use a mobile for any purpose. 8. You are not allowed to use calculators or any other electronic device. For Office Use Only Part Part I (35) Part II (25) Part III (20) Part IV (20) Total (100) Marks Part I: Programming, Data Structures, and Software Engineering (35 points) 1.1 a. What is a software development process model? (2 points) b. Explain in detail the Rapid Application development model. (3 points) 1.2 a. What is software risk? (2 points) Page -1- 1.8 Write the implementation of a simple sorting algorithm with a programming language of your choice to order a list having n integer values in descending order. (5 points) Page -4- Part II: Computer Architecture and Operating Systems (25 points) 2.1 In the 16-bit FLAGS register, 9 of the 16-bits are used as flags. What are the two groups in which these flag bits are grouped? Describe the purpose of each group. (4 points) 2.2 Compare CISC and RISC in light of emphasis on the following points? (5 points) Point of Emphasis CISC RISC Program code size and clock cycle needed “LOAD” and “STORE” instructions Transistors much needed for Hardware or Software emphasis Instructions’ complexity 2.3 In von Neumann architecture, the scheme of segment plus offset allows a program code or data to be relocate able. Describe in your words what relocation is and how it is done. (4 points) Page -5- 2.4 In most modern operating systems, making use of threads in a single process is common. Write two basic reasons (advantages) for using threads. (2 points) 2.5 Direct Memory Access (DMA) is commonly available in general-purpose modern computer systems. What are the disadvantages of a system without a DMA? (2 points) 2.6 What are the four types of files supported by the Unix operating system? (2 points) 2.7 Paging and segmentation are two common methods of implementing virtual memory. Unlike pages, segments do not have fixed size and have independent linear address space. Give two advantages of segmentation over paging. (3 points) 2.8 What is the Master Boot Record (MBR) in a file System? What happens to the system if the MBR is destroyed, say by a virus? (3 points) Page -6- c. Produce a listing: CUSTNAME, NO_OF_ORDERS, AVG_ORDER_AMT, where the NO_OF_ORDERS is the total number of orders by the customer and the AVG_ORDER_AMT is the average order amount for that customer. (3 points) d. List the orders that were not shipped within 30 days of ordering. (1.5 points) e. List the OrderNo for orders that were shipped from all warehouses that the company has in ‘Addis Ababa’. (3 points) Page -9- 3.2 What is the difference between logical data independence and physical data independence? (3 points) 3.3 How do we transform n-ary relationships between entities in E-R diagram into relations? Give an example. (3 points) 3.4 Is a relation in 3NF also in BCNF? Justify your answer and give a relevant example. (4 points) Page -10- Part IV: Computer Networks and Data Communications (20 points) 4.1 For each of the following questions, circle the letter of the correct answer. (1 point each) i. A set of rules governing communication within and between computing end points is described as a. Point-to-point b. Protocol c. Medium d. Duplex ii. To which layer(s) of the IEEE 802 does the data link layer of the OSI/ISO reference model map? a. Physical b. LLC c. MAC d. a and b e. b and c iii. The following are functions of a router except a. Traffic isolation b. Broadcast storm protection c. Optimal routing d. Internetworking e. None of the above iv.. Networks in a company are best described as a. Internet b. internet c. Intranet d. Extranet v. Which of the following OSI/ISO layer relives other upper layers from the burden of knowing the attached internetworking devices such as Routers, Switches, etc.? a. Application layer b. Data Link layer c. Network Layer d. Transport layer e. Physical layer vi. In a TCP/IP peer-to-peer network, which of the following layer(s) is not required? a. Data link layer b. Internet/Internetworking layer c. Physical layer d. None of the above e. All of the above vii. An application layer address is called a. MAC address b. Port number c. Host name d. IP address e. All of the above viii. Which of the following layer(s) is involved in the sending and receiving hosts as well as in the intermediary nodes such as routers? a. Application layer b. Network layer c. Transport layer d. None of the above e. All of the above 4.2. Mention one mechanism which is used in a data communication network to detect error during transmission _________________________________ (1 point) 4.3 Mention and briefly describe two media access protocols. (2 points) Page -11-