OS Quiz - I

30 Questions | Total Attempts: 212

SettingsSettingsSettings
Please wait...
OS Quiz - I

Instructions: Attempt all questions. Do not use any kind of helping material (Serach Engine, Books etc)


Questions and Answers
  • 1. 
    Round robin scheduling is essentially the preemptive version of 
    • A. 

      FIFO

    • B. 

      Shortest job first

    • C. 

      Shortest remaining

    • D. 

      Longest time first

  • 2. 
     Let S and Q be two semaphores initialized to 1, where P0 and P1 processes the following statements wait(S);wait(Q); ---; signal(S);signal(Q) and wait(Q); wait(S);---;signal(Q);signal(S); respectively. The above situation depicts a
    • A. 

      Semaphore

    • B. 

      Deadlock

    • C. 

      Signal

    • D. 

      Interrupt

  • 3. 
    The state of a process after it encounters an I/O instruction is 
    • A. 

      Ready

    • B. 

      Blocked/Waiting

    • C. 

      Idle

    • D. 

      Running

  • 4. 
    PCB stands for
    • A. 

      Program Control Block

    • B. 

      Process Control Block

    • C. 

      Process Communication Block

    • D. 

      None of the options

  • 5. 
    The Banker's algorithm is used 
    • A. 

      To prevent deadlock in operating systems

    • B. 

      To detect deadlock in operating systems

    • C. 

      To rectify a deadlocked state

    • D. 

      None of the options

  • 6. 
    ___________  is a high level abstraction over Semaphore. 
    • A. 

      Shared memory

    • B. 

      Message passing

    • C. 

      Monitor

    • D. 

      Mutual exclusion

  • 7. 
    Switching the CPU to another Process requires to save state of the old process and loading new process state is called as 
    • A. 

      Process Blocking

    • B. 

      Time Sharing

    • C. 

      Context Switch

    • D. 

      Multiprogramming

  • 8. 
    32 bit OS such as can only access 4 GB RAM atmost (there is no other technique to access more memory on 32 bit OS)
    • A. 

      True

    • B. 

      False

  • 9. 
    Master Boot Record is the first sector of unformatted disk. 
    • A. 

      True

    • B. 

      False

  • 10. 
    In a multithreaded environment main thread terminates after the termination of child threads. 
    • A. 

      True

    • B. 

      False

  • 11. 
    Which of the following disk scheduling techniques has a drawback of starvation ? 
    • A. 

      SCAN

    • B. 

      SSTF

    • C. 

      FCFS

    • D. 

      LIFO

  • 12. 
    When two or more processes attempt to access the same resource a _________ occurs. 
    • A. 

      Critical section

    • B. 

      Fight

    • C. 

      Communication problem

    • D. 

      Race condition

  • 13. 
     ________ scheduler selects the jobs from the pool of jobs and loads into the ready queue. 
    • A. 

      Long term

    • B. 

      Short term

    • C. 

      Medium term

    • D. 

      None of the options

  • 14. 
    A thread is a Heavy Weight  process . 
    • A. 

      True

    • B. 

      False

  • 15. 
    Trap is 
    • A. 

      A software interrupt

    • B. 

      A hardware interrupt

    • C. 

      Unmaskable

    • D. 

      an exception or a fault

    • E. 

      Asynchonous

  • 16. 
    Using Priority Scheduling algorithm, find the average waiting time for the following set of processes given with their priorities in the order: Process : Burst Time : Priority respectively . P1 : 10 : 3  P2 : 1 : 1   P3 : 2 : 4  P4 : 1 : 5  P5 : 5 : 2
    • A. 

      8 milliseconds

    • B. 

      8.2 milliseconds

    • C. 

      7.75 milliseconds

    • D. 

      3 milliseconds

  • 17. 
    Aging is a technique to avoid starvation in a scheduling system.
    • A. 

      True

    • B. 

      False

  • 18. 
    Marshalling is process of packaging and sending interface method parameters across thread or process boundaries.
    • A. 

      True

    • B. 

      False

  • 19. 
    State whether true or false.  i) Multithreading is useful for application that perform a number of essentially independent tasks that do not be serialized. ii) An example of multithreading is a database server that listens for and process numerous client request.
    • A. 

      i-True, ii-False

    • B. 

      I-True, ii-True

    • C. 

      i-False, ii-True

    • D. 

      I-False, ii-False

  • 20. 
    Consider the following set of processes, with the arrival times and the CPU burst times given in milliseconds. ------------------------------------- Process    Arrival-Time    Burst-Time -------------------------------------  P1 0 5  P2 1            3  P3 2            3  P4 4            1 ------------------------------------- What is the average turnaround time for these processes with the preemptive shortest remaining processing time first (SROT) algorithm?
    • A. 

      5.50

    • B. 

      5.75

    • C. 

      6.00

    • D. 

      6.25

  • 21. 
    Consider three processes (process id 0, 1, 2 respectively) with compute time bursts 2, 4 and 8 time units. All processes arrive at time zero. Consider the longest remaining time first (LRTF) scheduling algorithm. In LRTF ties are broken by giving priority to the process with the lowest process id. The average turn around time is:
    • A. 

      14 units

    • B. 

      13 units

    • C. 

      15 units

    • D. 

      16 units

  • 22. 
    Consider the 3 processes, P1, P2 and P3 shown in the table ---------------------------------------------- Process     Arrival time    Time unit required ----------------------------------------------   P1              0                    5   P2              1                    7   P3              3                    4 ---------------------------------------------- The completion order of the 3 processes under the policies FCFS and RRS (round robin scheduling with CPU quantum of 2 time units) are
    • A. 

      FCFS: P1, P2, P3 RR2: P1, P2, P3

    • B. 

      FCFS: P1, P3, P2 RR2: P1, P3, P2

    • C. 

      FCFS: P1, P2, P3 RR2: P1, P3, P2

    • D. 

      FCFS: P1, P3, P2 RR2: P1, P2, P3

  • 23. 
    The average memory access time for a machine with a cache hit rate of 90% where the cache access time is 10ns and the memory access time is 100ns is
    • A. 

      55ns

    • B. 

      45ns

    • C. 

      90ns

    • D. 

      19ns

  • 24. 
    At a particular time, the value of counting semaphore is 10. it will become 7 after
    • A. 

      3 V operations

    • B. 

      5P operations

    • C. 

      5V and 2P operations

    • D. 

      13 P and 10 V operations

  • 25. 
    In real time operating systems, which of the following is the most suitable scheduling scheme?
    • A. 

      round- robin

    • B. 

      FCFS

    • C. 

      Pre-emptive scheduling

    • D. 

      Random scheduling

Back to Top Back to top