Page 1 of 20 Semester 2 2019 FIT 1047 Sample Exam Faculty of Information Technology Note that this is a sample exam only. It is only made available for training purposes and does not contain questions from the actual exam. This sample exam is designed to be completed in 3 hours, while the actual exam will be just 2 hours and will therefore have fewer questions. The goal is to self-test and get an idea of the character of questions that can be expected in the actual exam. In the actual exam it is not permitted to use any material, books, or calculators. The idea of this exam is to try to solve all the questions on your own and if you don’t know the answers, go back to the material or to consultation to understand the topic. Very often, just looking at the solution can create the illusion that you would also be able to do it yourself. Important Disclaimer: Preparing for Your EXAM • This sample questions are only limited and small samples chosen to give you some directions with type of Q to expect. • We have in the lecture slides & covered in the lab/tutorials are all important and it is expected you should study and prepare from them It is advisable to complete your required preparation(s) as quickly as possible and be prepared at least 1 weeks before your exam. The sample exam and coverage can provide ONLY sample preparation materials to help you prepare for the exam. The Sample exam Questions above ARE NOT designed to provide you with all exam coverage for final exam assessment of your current skill levels, but to orient you to the style of question used in the actual final exam assessment. DO NOT treat the sample questions as the ONLY scope for your practice exam, or as the actual exam. The final Questions will vary considerably in their content, coverage and the level of difficulty. Solutions for this sample exam will be available from June 5th for you to check that your solutions are correct. However, you should try to complete all questions without looking at solutions first. Page 2 of 20 Part A: Multiple Choice Questions Instructions: 1. Each question has only one correct answer. Select the single, best choice for each question. 2. No penalty is applied for incorrect answers. 3. Ambiguous responses will be ignored. 4. Incorrect filling of the solution table with lead to marks not being correctly assigned. Question 1. Which base is usually used to display a binary file to a user? a) Base 2 b) Base 8 c) Base 10 d) Base 16 e) None of the above Question 2. Adding the two signed magnitude binary numbers 01000101 and 00011101 equals? a) 10001101 b) 11101010 c) 11010101 d) 01100010 e) None of the above Question 3. What are the decimal values for the two signed magnitude numbers 01001101 and 10011101? a) 77 and 28 b) 72 and -22 c) 77 and -29 d) -80 and -16 e) None of the above Question 4. Subtracting 01110011 from 00001011 using 2’s complement notation equals? a) 10011000 b) 11010101 c) 00101100 d) 11010100 e) None of the above Question 5. How many different numbers can be represented with n bits? a) n b) 2n c) log2(n) d) 16 e) 32 Question 6. Which of the following basic circuits is used in an ALU? a) An S/R adder b) A multiplexer c) A D-Flipflop d) A 2’s complement e) A decoder Question 7. Assume a computer architecture where instructions are 64 bits long, which contain a 56 bit memory address, and enough bits to address 8 registers. What is the maximal number of different opcodes this computer architecture can support? Page 3 of 20 a) 3 b) 7 c) 5 d) 16 e) 32 Question 8. Which sequence of instructions in MARIE assembly code results in the value stored at address 123 to be negated? a) Load 0, Subt 123, Store 123 b) Clear, SubtI 123, StoreI 123 c) Load 0, SubtI 123, Store 123 d) Clear, Subt 123, Store 123 e) Load 0, Subt 123, StoreI 123 Question 9. What is a context switch? a) The operating system switching from one process to another b) An I/O device that requests that the CPU deals with new input c) A signal raised by the currently running process that causes the operating system to perform I/O. d) A timer event that causes the operating system to perform process scheduling. Question 10. Which of the following is not a typical function of operating systems? a) Managing the CPU’s fetch-decode-execute cycle b) Handling hardware interrupts c) Managing virtual memory d) Providing a graphical user interface e) Providing access to I/O devices Question 11. Which of the following is a difference between preemptive timesharing and cooperative timesharing? a) Preemptive t. is used in practice, cooperative t. is not. b) Preemptive t. can interrupt malicious or buggy processes, cooperative t. cannot. c) Preemptive t. does not require hardware support, cooperative t. does. d) Preemptive t. does not require cooperation from the user, cooperative t. does. e) Preemptive t. makes processes run more efficiently compared to cooperative t. Question 12. Which of the following scheduling mechanisms can achieve fairness? a) Round-robin scheduling b) Cooperative scheduling c) First-come first-served d) Last-in first-out e) Memory scheduling Question 13. ARQ means that a) a receiver that detects an error in a message asks the sender to retransmit the message until it is received without error. b) the common carrier Automatically Returns Queries to the subscriber upon receipt of such queries. c) a sender is using a data link protocol called Asynchronous Repeating reQuest. d) a fiber optic cable meets the American Registered Quality, a certification standard for use in high-quality data communication transmission lines. e) a sender is using a parity scheme called Array Resource Quality. Page 4 of 20 Question 14. Which of the following problems is addressed by the CA part of CSMA/CA? a) The “hidden node” problem in wireless LANs. b) The “spam” problem in email networks. c) The “Certification Authority” problem in public key cryptography. d) The “Collision Avoidance” problem in wired Ethernet. Question 15. How does TCP identify the application layer process that should handle a message? a) Using the IP address. b) Using the MAC address. c) Using the port number. d) Using the process ID. e) Using the application ID. Question 16. Which of the following is not part of the TCP protocol? a) The four-way handshake. b) The three-way handshake. c) Acknowledgement numbers. d) Sequence numbers. e) HTTP status codes. Question 17. A “client-server” architecture approach a) places all or almost all of the application logic on the client b) places all or almost all of the application logic on the server c) places all or almost all of the data storage logic on the client d) places all or almost all of the presentation logic on the server e) places all or almost all of the network logic on the client Question 18. Which of the following parameters deteriorates with distance between sender and receiver? a) Bandwidth b) Burst rate c) Frame rate d) Committed Information Rate e) Latency Question 19. Which of the following is an independent malicious program that enables the attacker to remotely control the computer? a) Virus b) Worm c) Trojan Horse d) Backdoor e) Bot Question 20. Digital signatures ensure that a message has not been a) intercepted b) delayed c) forwarded d) forged e) read Question 21. One main role of a packet-filter firewall is to drop packets that do not match the criteria defined in policy rules. What are typical parameters? a) Content on application layer b) MAC addresses Page 5 of 20 c) source and destination IP addresses and ports d) route of the packet e) digital signatures Question 22. Which does IDS stand for in network security? a) Information Decryption System b) Intelligent Data Security c) International Defense Society d) Internet Decoding Specification e) Intrusion Detection System Question 23. Which property is required for storing passwords? a) Confidentiality b) Authenticity c) Non-repudiation d) Privacy e) Integrity Question 24. Which of the following mechanism can be instantiated as software on individual PCs or in hardware as
a special device in the network ? a) Firewalls b) Virus scanners c) Intrusion detection d) Backup e) All of the above Page 6 of 20 Part B: Short Answer Questions (Marks show for questions are just indicative) Question 1. [4 marks]: Name and briefly explain the feature of modern CPUs that is used to restrict applications from accessing certain CPU functionality such as I/O. Question 2. [4 marks] a) How many bits are needed to express 1024 numbers? b) How many bits are in 32 Gibit? (Give answer in power of 2) Question 3. [3 marks] Explain the subtraction of two positive integers using 2’s complement arithmetic. Page 7 of 20 Question 4. [3 marks] A 16-bit word in memory contains two 7-bit ASCII characters and one additional even parity bit for each character. The parity bit is the right-most bit. a) If you find 01101000 10001110. Would this be a valid representation of two characters? b) Which two characters are encoded in 10001101 01101010? ASCII Hexadecimal ASCII Binary (7-bit) Character Value 030 0110000 0 031 0110001 1 032 0110010 2 033 0110011 3 034 0110100 4 035 0110101 5 036 0110110 6 037 0110111 7 038 0111000 8 039 0111001 9 041 1000001 A 042 1000010 B 043 1000011 C 044 1000100 D 045 1000101 E 046 1000110 F 047 1000111 G 048 1001000 H Page 8 of 20 Question 5. [3 marks] Give one reason why signed integer arithmetic is not suitable for computation of 3D graphics. Question 6. [6 marks] Convert the following numbers as specified. Show all workings. 1. From base 10 to base 16: 1286 2. From base 10 to base 2: 2050 3. From base 16 to base 2: A F81C Page 9 of 20 Question 7. [6 marks] Convert the decimal integer -65 to an 8-bit binary representation in 2´s complement notation. Show all workings. Question 8. [3 marks] Using a truth table show that (¬ + ) = for all values of and . Page 10 of 20 Question 9. [2 marks] Draw a combinational circuit for the following Boolean function using only NOT, OR, and AND gates: (1, 2, 3) = 1¬2¬3 + 12¬3 +¬12¬3 Question 10. [5 marks] Identify the function of the circuit below. Give an example of inputs A and B (by writing into the squares) and fill in all intermediate and final outputs (dotted squares and circles). Page 11 of 20 Question 11. [6 marks] Identify and briefly explain the roles of the three main components of a Central Processing Unit. Page 12 of 20 Question 12. [3 marks] Describe the difference between a direct jump and an indirect jump instruction, using the MARIE system as an example. Question 13. [6 marks] Consider the program below, written in MARIE assembly language. The addresses at which the individual instructions and data values are stored in memory are shown in the left column, for your convenience. 000 Loop, LoadI Addr 001 SkipCond 400 / Skip if AC=0 002 Jump Compute 003 Load Result 004 Output 005 Halt 006 Compute, Add Result 007 Store Result 008 Load Addr 009 Add One 00A Store Addr 00B Jump Loop 00C One, DEC 1 00D Result, DEC 0 00E Addr, HEX 010 00F DEC 3 010 DEC 6 011 DEC 9 012 DEC 0 Assume that the processor starts executing the program from address 000. a) How many times will the instruction at address 001 be executed before the program reaches the Halt instruction? b) Which value will be stored at address 00E when the program reaches the Halt instruction? c) What is the value printed by the Output instruction (assuming the output mode is set to “decimal”)? Page 13 of 20 Question 14. [1 mark] Identify which MARIE instruction corresponds to the following RTL code: 1. MAR ← PC 2. MBR ← M[MAR] 3. IR ← MBR 4. PC ← PC+1 5. MAR ← X 6. MBR ← PC 7. M[MAR] ← MBR 8. AC ← MAR 9. PC ← AC + 1 Question 15. [3 marks] Briefly explain the concept of a flipflop circuit. Name a computer component where a flipflop is used. Question 16. [3 marks] Briefly explain the difference between sequential and combinational circuits. Question 17. [3 marks] Assume a memory that can store 216 bytes. What are the lowest and highest addresses, and how many bits are needed to store those addresses, if the memory is 1. Byte addressable 2. Word addressable with a word size of 16 bits Question 18. [1 marks] What does the abbreviation “POST” stand for in a computer’s boot process? Page 14 of 20 Question 19. [2 marks] Give one possible reason why 3D graphics are usually not available for firmware (BIOS/UEFI) configurations. Question 20. [2 marks] Briefly explain the concept of a process, including the states it can be in. Page 15 of 20 Question 21. [3 marks] Briefly explain how the hardware and operating system work together to control how programs access I/O devices. Page 16 of 20 Question 22. [3 marks] Name and briefly explain the mechanism that operating systems use to provide each process with its own address space. Question 23. [4 marks] Name the layers of the TCP/IP architecture (also called the Internet Model), and briefly explain the function of layer 2. Question 24. [2 marks] Briefly explain how a switch works. Question [2 marks] Briefly explain how a router works. Page 17 of 20 Question 25. [3 marks] Briefly describe the two-tier email architecture (using a diagram). Question 26. [2 marks] Name two different methods for transmitting digital data through cables. Question 27. [3 marks] Explain the advantage of roaming in wireless networks. Question 28. [1 mark] Name the acronym of the application layer protocol used for accessing the World Wide Web. Question 29. [3 marks] Are wireless LANs more or less secure than wired Ethernet? Explain your answer. Page 18 of 20 Question 30. [3 marks] Explain the high-level structure of the Internet. Question 31. [2 marks] What is the difference between interior and exterior routing protocols? Question 32. [4 marks] What are the end-points of the encrypted channel in a VPN connection? Explain why a VPN does not provide end-to-end security between a homw-office PC and a PC in the enterprise network. Question 33. [3 marks] Certificates are used to identify servers when using TLS. Give one reason, why certificates can be problematic. Page 19 of 20 Question 34. [6 marks] Explain the term demilitarised zone and provide 2 examples of firewall placements for such a zone. Question 35. [3 marks] Compare public Message Authentication Codes and Hash Functions showing 1 similarity and 2 differences. Question [3 marks] What is a currently recommended hash function for use in digital signatures and which hash function is still used, but no longer recommended. Page 20 of 20 Important Disclaimer: Preparing for Your EXAM • This sample questions are only limited and small samples chosen to give you some directions with type of Q to expect. • We have in the lecture slides & covered in the lab/tutorials are all important and it is expected you should study and prepare from them It is advisable to complete your required preparation(s) as quickly as possible and be prepared at least 1 weeks before your exam. The sample exam and coverage can provide ONLY sample preparation materials to help you prepare for the exam. The Sample exam Questions above ARE NOT designed to provide you with all exam coverage for final exam assessment of your current skill levels, but to orient you to the style of question used in the actual final exam assessment. DO NOT treat the sample questions as the ONLY scope for your practice exam, or as the actual exam. The final Questions will vary considerably in their content, coverage and the level of difficulty.
