HEC USAT-CS (Computer Science) computer science Operating Systems — Set 2

Operating Systems MCQs set 2 for HEC USAT-CS (Computer Science) computer science — 20 solved questions.

HEC USAT-CS (Computer Science) computer science Operating Systems — Set 2

  1. Question 1

    Q1. What is the primary function of the operating system's process scheduler?

    • A) Memory Management
    • B) Process Synchronization
    • C) CPU Allocation
    • D) File System Management

    Answer: CPU Allocation

    Explanation: The process scheduler allocates the CPU to processes, determining which process runs next, using algorithms like FCFS or SJF.

  2. Question 2

    Q2. What is a necessary condition for a deadlock to occur?

    • A) Mutual Exclusion
    • B) Hold and Wait
    • C) No Preemption
    • D) All of the above

    Answer: All of the above

    Explanation: Deadlock occurs when Mutual Exclusion, Hold and Wait, No Preemption, and Circular Wait conditions are met simultaneously.

  3. Question 3

    Q3. Which operating system concept is used to prevent starvation?

    • A) Aging
    • B) Priority Scheduling
    • C) Round Robin
    • D) FCFS

    Answer: Aging

    Explanation: Aging increases the priority of a process as it waits, preventing starvation by ensuring it eventually gets CPU time.

  4. Question 4

    Q4. What is the role of a semaphore in operating systems?

    • A) Process Synchronization
    • B) Memory Management
    • C) File System Management
    • D) CPU Scheduling

    Answer: Process Synchronization

    Explanation: Semaphores are used for process synchronization, controlling access to shared resources by multiple processes.

  5. Question 5

    Q5. In which scheduling algorithm does the CPU time get divided into fixed time slices?

    • A) FCFS
    • B) SJF
    • C) Priority Scheduling
    • D) Round Robin

    Answer: Round Robin

    Explanation: Round Robin scheduling divides CPU time into fixed time slices (time quanta), allocating each process a turn.

  6. Question 6

    Q6. What is the main advantage of using threads over processes?

    • A) Faster Context Switching
    • B) Improved Security
    • C) Better Resource Utilization
    • D) A and C

    Answer: A and C

    Explanation: Threads offer faster context switching and better resource utilization compared to processes, as they share the same memory space.

  7. Question 7

    Q7. Which operating system structure is known for its modular design?

    • A) Monolithic
    • B) Microkernel
    • C) Layered
    • D) Hybrid

    Answer: Microkernel

    Explanation: Microkernel architecture is modular, separating the kernel into smaller components for better maintainability and security.

  8. Question 8

    Q8. Which technique is used to handle the problem of thrashing?

    • A) Working Set Model
    • B) Page Replacement Algorithms
    • C) Aging
    • D) None of the above

    Answer: Working Set Model

    Explanation: The Working Set Model helps prevent thrashing by ensuring a process has its required pages in memory before executing.

  9. Question 9

    Q9. What is the purpose of a system call in an operating system?

    • A) To invoke kernel services
    • B) To manage file systems
    • C) To schedule processes
    • D) To handle interrupts

    Answer: To invoke kernel services

    Explanation: System calls provide a way for user-level programs to request services from the kernel, such as process creation or file access.

  10. Question 10

    Q10. In a multitasking operating system, what is context switching?

    • A) Switching between different user accounts
    • B) Switching the CPU between different processes
    • C) Changing the priority of a process
    • D) None of the above

    Answer: Switching the CPU between different processes

    Explanation: Context switching involves saving the state of the current process and restoring the state of the next process to be executed.

  11. Question 11

    Q11. What is the main function of a device driver in an operating system?

    • A) To manage file systems
    • B) To handle interrupts
    • C) To act as an interface between the OS and hardware
    • D) To schedule processes

    Answer: To act as an interface between the OS and hardware

    Explanation: Device drivers serve as intermediaries between the operating system and hardware devices, facilitating communication and data transfer.

  12. Question 12

    Q12. What is a monitor in the context of operating systems?

    • A) A synchronization construct
    • B) A type of file system
    • C) A scheduling algorithm
    • D) None of the above

    Answer: A synchronization construct

    Explanation: A monitor is a synchronization construct that allows only one process to access a shared resource at a time, preventing race conditions.

  13. Question 13

    Q13. What is the benefit of using a kernel with a microkernel architecture?

    • A) Improved Performance
    • B) Simplified Security
    • C) Modularity and Flexibility
    • D) None of the above

    Answer: Modularity and Flexibility

    Explanation: Microkernel architecture enhances modularity and flexibility by separating the kernel into smaller, independent components.

  14. Question 14

    Q14. In operating systems, what does ' spooling' refer to?

    • A) Simultaneous Peripheral Operations On-line
    • B) Simple Peripheral Operations Offline
    • C) Sequential Processing Of Large Jobs
    • D) None of the above

    Answer: Simultaneous Peripheral Operations On-line

    Explanation: Spooling is a technique where data is temporarily stored to be processed later, enabling simultaneous peripheral operations.

  15. Question 15

    Q15. What is the primary purpose of a file system's inode?

    • A) To store file data
    • B) To manage file metadata
    • C) To schedule disk I/O
    • D) To handle file permissions

    Answer: To manage file metadata

    Explanation: Inodes store metadata about files, such as ownership, permissions, and location on disk, facilitating file system management.

  16. Question 16

    Q16. Which algorithm is used for CPU scheduling in a uniprocessor system?

    • A) Round Robin
    • B) Priority Scheduling
    • C) Shortest Job First
    • D) All of the above

    Answer: All of the above

    Explanation: Various algorithms like Round Robin, Priority Scheduling, and Shortest Job First are used for CPU scheduling.

  17. Question 17

    Q17. What is the purpose of a 'semaphore' in Operating Systems?

    • A) Synchronize access to shared resources
    • B) Manage memory allocation
    • C) Handle interrupts
    • D) Control file access

    Answer: Synchronize access to shared resources

    Explanation: Semaphore is a variable that controls access to shared resources, preventing simultaneous access.

  18. Question 18

    Q18. Which data structure is used to manage the 'ready queue'?

    • A) Stack
    • B) Queue
    • C) Tree
    • D) Graph

    Answer: Queue

    Explanation: A queue is used to manage the 'ready queue', where processes wait for CPU allocation.

  19. Question 19

    Q19. What is the function of a 'dispatcher'?

    • A) Save the context of the previous process
    • B) Restore the context of the next process
    • C) Give control of the CPU to the next process
    • D) All of the above

    Answer: All of the above

    Explanation: Dispatcher saves the context of the previous process, restores the context of the next process, and gives control of the CPU.

  20. Question 20

    Q20. What is 'paging' in memory management?

    • A) Divide memory into fixed-size blocks
    • B) Divide memory into variable-size blocks
    • C) Use a single contiguous block of memory
    • D) Use a cache memory

    Answer: Divide memory into fixed-size blocks

    Explanation: Paging involves dividing memory into fixed-size blocks called 'pages' and 'frames'. NET computer science MCQs often test this core concept.