SIR MICHELANGELO REFALO SIXTH FORM

Transcription

1 SIR MICHELANGELO REFALO SIXTH FORM Annual Exam 2016 Subject: Computer Advanced Time: 3 hours 1. System modularisation refers to dividing a system into smaller pieces explain a. What makes a good module? Name three different aspects which make a module well programmed for further enhancements. [3] b. During testing, a tester can test a system using a bottom up approach. Explain what is bottom up and give a proper example. [3] c. Another feature of modularisation is code reusability. Explain what code reusability is and how modularisation can help in such circumstances. [3] d. How is modularity implemented in JAVA [1] 2. The operating system handles a number of processes a. Name the main three states that a process can be. b. Explain in detail each state by giving proper examples in order to explain better the states. [3] c. What is virtual memory? In case you were an OS programmer which states of a process would be placed on virtual memory? Justify your answer. [3] d. Which part of the OS is responsible of deciding which process is to be processed? Page 1 of 6 Computer Advanced 2016

2 3. Scheduling in Operating systems is very important. a. What is the job of the scheduler? b. Name three different ways how to dispatch process to the CPU. [3] c. When scheduling process Deadlock may occur. Name the 4 aspects which must be present for a deadlock to occur. d. State how we can avoid deadlock. e. How can OS recover from a deadlock? [1] 4. An array of integers needs to be sorted 63, 18, 33, 32, 17, 26, 22 a. What is the best case, worst case and average case of bubble sort? b. Write the algorithm for bubble sort. c. BST are very useful in sorting elements. Draw a binary search tree of the above number list. d. Traverse this data structure using Inorder, preorder and post order. e. Binary search is said to be efficient to find an item in a list. Write the algorithm of Binary search and state any conditions required for a binary search to work. Page 2 of 6 Computer Advanced 2016

3 5. K Maps a. Using a K-map obtain a minimized expression for the following truth table. b. Draw the diagram of the simplified expression. c. Arrange the logic expression in order to use only NOR gates. d. Draw the circuit using ONLY NOR gates. [2,2] A B C X Dc Dc This question is on networks a. Name the 7 layers of the OSI Model b. In brief explain the function of each layer. [4] c. Differentiate between simplex, half duplex and full duplex communication. d. WiFi is very popular network connection. Why is WiFi so popular and what disadvantage it brings to network connections. Page 3 of 6 Computer Advanced 2016

4 7. This question is on System Analysis a. What are the main aspects of Feasibility Study during the System Development life cycle? b. What makes a program a good program? Name three requirements for a program in order to be good program. [3] c. What is the purpose of the following documentation in a new system: Installation Manual, Operations Manual and Technical manual? Name features you will find in such documentation. [3] d. JSP and HIPO diagrams are important in System analysis and design. Define the two tools and state their use. 8. Information System are mostly databases. A cycling club has a list of members. Each season the club participates in a number of races around Malta. The club keeps details of each race, for example the member Leli Said came first in the Mellieha race. a. Your duty is to list the tables and the fields your think are useful in such a database. b. Normalize your answer in 3 rd normal form. These should be written in short notation (standard database notation). Do not forget the primary keys and secondary keys. c. Draw the ER diagram. d. Explain what is meant by a database to be in 3NF. e. Explain the following database terminologies: tuples, attributes and secondary keys. Page 4 of 6 Computer Advanced 2016

5 Section 2 Answer ONLY ONE question from this segment Question A A seven segment led display is used to show a range of digits (4 bits). One of the segments (middle one) is always lit when the following digits are displayed: 2,3,4,5,6,8,9 a. Draw a truth table in terms of X when the middle segment is switched on. [4] b. Simplify using a K-map. c. Represent the expression by drawing a circuit. d. Using 8 bit mantissa and 4 bit exponent (both two s complement) normalise the following numbers: i ii e. What is a character set? Name two character set you know and compare between the two. f. What are the errors overflow and underflow when doing arithmetic in binary. g. Proof that A B C + A B + A B C + A C = (A XOR C) + B using the laws of Boolean algebra. [4] Page 5 of 6 Computer Advanced 2016

6 Question B Java: A Real Estate agency is thinking of computerising its booking system. The company has property for Sale as well as for Rent. For each property the company logs: The address, property id, no of bedroom, no of bathrooms and square meters. If the property is for sale the company logs the price of the house, on the other hand if the property is for rent a price per month and whether the property is commercial or residential is recorded. For each property the agency must calculate the commission to be paid. If the property is for sale a commission of 8% on the total price of the house is paid. If the property is for rent a commission of 3% is paid on the price per month. (create an abstract method) a. Draw the class diagrams for the above scenario. i. show the attributes and methods, ii. constructors iii. abstract methods iv. inheritance [8] b. Translate the class Property and class Sale to Java classes (code) i. Override the constructors ii. Implement any abstract methods iii. Create setter and getters iv. Encapulusate the attributes. v. Show inheritance c. Create an object of type Sale with the following values. You can use the constructor or setters. i. SaleProperty Victoria, S10221, 4,2,200,Euro 200,000 Page 6 of 6 Computer Advanced 2016