Operating Systems Fundamentals
Based on the above information, which of the following is NOT TRUE? A. The user's password is 1875 B. The path to the user's shell is /bin/bashC. The username is liam D. The user id is 2930
2. Which of the following is NOT TRUE about Process Control Block (PCB)? A. Process number (PID) and state, program counter, CPU-related information, memory management information, accounting information and I/O status information are stored in the PCBB. b. Each process has its own process control block C. When a CPU switches to another process, the system must first load the PCB of the new process before saving the state of the old process D. d. The context of a process is stored in a PCB
3. Which of the following is NOT TRUE about the component of a Hard Disk Drive (HDD)?A. A track is a concentric circular strip on the surface of a disc platterB. A spindle is a part of the HDD that holds and rotates the plattersC. A sector is a set of tracks that are located at the same head position D. Each disk platter has the same amount of sectors and tracks
4. Which of the following is NOT TRUE about logical formatting? A. A directory file contains the name of the directory and the names of all of its children (files and sub-directories) B. A File is an abstract data type and it is logically contiguous but may be physically fragmented on a diskC. A Master Boot Record (MBR) contains the code to boot OS from a disk D. A Cluster is a contiguous group of tracks that are located at the same head position
5. Which of the following is NOT TRUE about Process Execution? A. All threads in a process share the same program counter, registers, stack, signals and signal handlersB. Process execution consists of a cycle of CPU execution and I/O wait and it is called CPU-I/O Burst cycleC. The ready queue contains a set of processes that are in either ready or waiting state D. Threads are entities within a process and they are used to schedule program execution on CPU 6. Which of the following is NOT TRUE about File/Directory permissions?A. You do not need to set a script file (e.g. bat, sh, php, cgi) or a program file to be executable. You would only need to set it to be readable to run the file. B. Directory read permission is the permission to read the name of a directory C. File write permission is the permission to modify the content of a fileD. Directory execute permission is the permission to open a directory
7. Which of the following is NOT TRUE about Secondary Storage?A. RAM is an example of a Secondary Storage deviceB. A Hard Disk Drive contains rapidly rotating rigid metallic platters with magnetic heads to read and write data from the platters C. Solid State Drives are more durable and have faster writing speeds than Hard Disk DrivesD. DVD and Blu-Ray are examples of secondary storage devices
8. Which of the following is the CORRECT command to set the permission of Test1.php? File Name User Group Other Read Write Execute Read Write Execute Read Write Execute Test1.php ✓ ✓ ✓ ✓ ✓ ✓ A. chmod 764 Test1.php B. chmod 731 Test1.phpC. chmod 761 Test1.phpD. chmod 016 Test1.php
9. Which of the following is TRUE about Bus?A. A bus is the connection point between a device and a computer B. A Data Bus is used to get/send signals to the I/O devices C. A Control Bus is used to get/send physical memory addresses D. A bus is a common set of wires used by one or more devices
10. Which one of the following is NOT TRUE about OSes (Operating Systems)?A. OSes keep track of the amount of resources used by each userB. OSes manage memory, processors, files and devices C. OSes serve as an intermediary between users, hardware, and software applicationsD. OSes are only used to display a graphical user interface (GUI)
11. Which of the following CORRECTLY describes a file that has a permission of - r-x r-- ---? A. It is a file that can only be read by the user/owner and the group B. It is a file that everyone (user, group and others) can read C. It is a file that can only be executed by the group D. It is a file that everyone (user, group and others) can modify/write 12. Which of the following is NOT TRUE about Malware?A. A Trojan horse is a non-self-replicating malware that drops malicious payloads and creates backdoors B. A Malware is a computer program that is used to breach computer securityC. A Spyware is a standalone malware that tries to gather and send information about the system without the user's permission D. A Resident virus is a type of virus that will remain in the Master Boot Record of a hard disk
13. Which of the following is NOT TRUE about processes?A. A foreground process is a process controlled via user interface and Background process is a program running in memory but it is not visually visible to the users B. A process has 5 possible states: new, running, ready, waiting and terminatedC. Text section, program counter, stack, data section and heap are stored in a process contextD. A process is a passive entity stored on a disk
14. Which one of following is NOT TRUE about Process Creation and Termination? A. If no parent is waiting, the terminated child process is called an orphanB. A parent may terminate its child process because the child has exceeded its usage of the allocated resources C. A parent may terminate its child process via abort() D. In Unix, exec() system call replaces the current process' memory with a new program
15. Which of the following is NOT TRUE about Process Scheduling? A. In multilevel queue scheduling, foreground processes have higher priority over background processesB. CPU process scheduling criteria are: CPU utilization maximization, throughput maximization, waiting time minimization, response time minimization and turnaround time maximizationC. The goal of a CPU scheduler is to ensure that each process has a fair share of the CPUD. Throughput is the number of processes that are completed per time unit
16. Which one of the following is NOT TRUE about OS's shells? A. A shell is a command interpreter B. A shell accepts commands that users enter and passes them on to the kernel C. A shell is located between the software applications and the kernel D. Only one shell can run at the same time
17. Which one of the following is NOT TRUE about an OS's kernel?A. Kernel is located between software applications and shells B. Kernel is the lowest level of software in the OSC. Kernel communicates with shells and hardware D. Kernel manages the hardware resources 18. Which of the following is NOT TRUE about User Authentication? A. Compared to static passwords, one-time passwords are less prone to man-in-themiddle attacksB. A static password is a password that a user can use at all times to loginC. User Authentication is a method for verifying the identity of a user D. A one-time password is a password that is valid for only one login session or transaction
19. Which one of the following is NOT TRUE about User interfaces in OSes (Operating Systems)?A. In MS-DOS mode, a command prompt (e.g., C:>) is an example of CLI B. CLI and GUI stand for Command Line Interface (or Interpreter) and Graphical User Interface, respectivelyC. Both GUI and CLI are implemented below the Kernel D. An OS may have both GUI and CLI, and in a multi-tasking mode they can run at the same time
20. Which one of the following is CORRECT about System Calls in OSes? A. System calls are functions (procedures) that you/applications use to interact with the kernel B. Linux, Windows and Mac OS have exactly the same system calls C. System calls are programs for passing messages between software applicationsD. Windows Task Manager is an example of a system call Section B – Matching Note: Match the best answer to the question. Each answer may be used once only and each question is worth 2 marks
A. Process Control Block 1. Is the textual representation of a command interpreter/shellB. Non-volatile 2. Divides an Operating System into a number of layers, each one built on top of lower layers.C. Sockets 3. Stores the context information about an individual process, such as process number and process state.D. Malicious Attack 4. Is a situation where a process producer tries to write data into a bounded buffer which was already full.E. CLI 5. Is a low-level data communication mechanism used by a client to communicate with a server.F. Buffer overflow 6. Is a method for breaking memory into logical pieces. Each piece represents a group of related information.G. Two-step Authentication 7. Is a type of memory that permanently stores information even when there’s no power.H. Address Bus 8. Is used to get/set physical memory addresses.I. Segmentation 9. Is a process of verifying a user identity through 2 different authentication methods.J. Layered approach 10. Is a situation where a user is deliberately trying to find and expose a flaw in the system.
Section C – Short Answer Questions 1. What are 3 advantages of OS Loadable Kernel Modules? [6 marks] 2. What are 2 possible reasons for an idle process? [4 marks] 3. What are 3 CPU Scheduling Criteria? For each criterion, specify whether the CPU Scheduler should try to minimize or maximize it. [6 marks] 4. Which type of Computer Storage (ROM or Registers): A. Is used to store the value of a variable? [1 mark]B. Can store more data (larger memory size)? [1 mark] C. Is read-only (not rewriteable)? [1 mark] D. Has a faster read speed? [1 mark]
5. Alice has created a file called Starship.js. Alice and Jack belong to a group called Pilot. John and Ben do not belong to any group. The table below shows the access control of the Starship.js file. r w x r W x r W X√ √ √ √ √
Based on the table above, answer the following questions: A. Can Alice execute the file? [1 mark] B. Can Alice change the content of the file? [1 mark] C. Can Jack modify the content of the file? [1 mark]D. Can Ben read the content of the file? [1 mark] E. Can John run the file? [1 mark]
6. What is a Device driver and why do we need it? [4 marks]
7. For each of the following malware, please briefly describe whether they are standalone programs, can replicate themselves and can create backdoors: A. Virus [3 marks]B. Trojan Horse [3 marks] C. Worms [3 marks]
8. Which type of Virus (Boot Sector or Resident): A. Is located in the RAM? [1 mark]B. Will only disappear when a user performs a clean logical formatting on the hard disk