June 23, 2024

Operating Systems MCQ Questions and Answers

Operating Systems
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Operating Systems MCQ Questions & Answers


Quiz – 3
  1. Which of the following acts as the interface between user and the computer to manage hardware components
    a. Utilities
    b. Application software
    c. Operating system
    d. System calls
  2. The operating system that operates on actual time of the system is
    a. Time Sharing System
    b. Real time System
    c. Parallel Systems
    d. Batch Systems
  3. The number of processes completed per unit time is known as __________
    a. Efficiency
    b. Output
    c. Throughput
    d. Capacity
  4. This provides a communication facility between the client program and the various services that are also running user space
     a. System Bus
    b. Modules
    c. Micro kernel
    d. File Systems




  5. To access the services of operating system, the interface is provided by the OS is ___________
    a. Library
    b. Instructions
    c. API
    d. System calls
  6. The amount of Time that is required to execute a specific process
    a. Response time
    b. Burst Time

    c. Completion Time
    d. Turnaround time
  7. Thread is a
     a. Light weight process
    b. Heavy weight process
    c. Multi process
    d. I/O related process
  8. Multithreading models are _________ types?
    a. 3
    b. 2
    c. 5
    d.4




  9. Which of the following algorithms tends to minimize the process flow time?
    a. Longest Job First
    b. Earliest Deadline First
    c. First come First served
    d. Shortest Job First 
  10. Which of the following statements are true?
    I. Shortest remaining time first scheduling may cause starvation
    II. Preemptive scheduling may cause starvation
    III. Round robin is better than FCFS in terms of response timea. II and III only
    b. I, II and III
    c. I only
    d. I and III only
  11. What is interprocess communication?
    a. communication between two threads of same process
    b. Communication between multiple tread of same process
    c. communication between two processes
    d. communication within the process
  12. Semaphore is a/an _______ to solve the critical section problem
    a. float variable
    b. special program for a system
    c. none of the mentioned
    d. hardware for a system




  13. Each process Pi, i = 0,1,2,3,……,9 is coded as follows.
    repeat
    P(mutex)
    {Critical Section}
    V(mutex)
    forever
    The code for P10 is identical except that it uses V(mutex) instead of P(mutex). What is the largest number of processes that can be inside the critical section at any moment (the mutex being initialized to 1)?
    a. 4
    b. 2

    c. 1
    d. None of the mentioned
  14. In the index allocation scheme of blocks to a file, the maximum possible size of the file depends on
    a. the number of blocks used for the index, and the size of the blocks
    b. the size of the blocks, and the size of the address of the blocks.
    c. None of the above
    d. the size of the blocks, the number of blocks used for the index, and the size of the address of the blocks
  15. To maintain the acyclic structure of the system, the operating system …. ……the links when traversing directory trees. 
    a. ignores
    b. considers
    c. None of the mentioned
    d. deletes
  16. File attributes consist of ____________
    a. type
    b. name
    c. identifier
    d. all of the mentioned




  17. Consider disk has 200 tracks. Say there is a request: 15, 20, 44, 82, 141, 180, and 190. The Using CSCAN scheduling find the total seek time if the read/write head is at 40 and moving towards bigger number
    a. 343
    b. 180
    c. 223
    d. 312
  18. .____________ scheduling may cause starvation of some requests.
     a. FCFS
    b. C-SCAN
    c. SCAN
    d. SSTF
  19. For an effective operating system, when to check for deadlock?
    a. every time a resource request is made at fixed time intervals
    b. randomly
    c. at fixed time intervals
    d. every time a resource request is made 
  20. Which one of the following is not Disk scheduling 
    a. LIFO
    b. CLOOK
    c. Preemptive
    d. Priority





Quiz – 2
  1. To avoid deadlock_______.
    a. resource allocation must be done only once
    b. all deadlocked processes must be aborted
    c. inversion technique can be used
    d. there must be a fixed number of resources to allocate
  2. When a program tries to access a page that is mapped in address space but not loaded in physical memory, then
    a. no error occurs
    b. fatal error occurs
    c. segmentation fault occurs
    d. page fault occurs
  3. Which algorithm chooses the page that has not been used for the longest period of time whenever the page required to be replaced?
    a. first in first out algorithm
    b. least recently used algorithm
    c. additional reference bit algorithm
    d. counting based page replacement algorithm
  4. What is the formula for Hit Ratio?
    a. Miss/(Hit + Miss)
    b. (Hit Miss)/Miss
    c. Hit/(Hit+ Miss)
    d. (Hit+ Miss)/Hit


  5. The strategies like the first fit, best fit and worst fit are used to select a
    a. free hole from a set of available holes
    b. process from a queue to put in memory
    c. process from a queue to put in storage
    d. processor to run the next process
  6. In FIFO page replacement algorithm, when a page must be replaced
    a. random page is chosen
    b. newest page is chosen
    c. none of the mentioned
    d. oldest page is chosen
  7. Which of the following options describes the sequential file access method?
    a. Accessing bytes randomly based on the given byte number
    b. Reading bytes one by one in a specific order
    c. Randomly reading or writing data by record
    d. Sequentially reading or writing data by record
  8. When two users keep a subdirectory in their own directories, the structure being referred to is_______.
    a. acyclic graph directory
    b. two-level directory structure
    c. tree structure
    d. cyclic graph directory structure




  9. To maintain the acyclic structure of the system, the operating system………..the links when traversing directory trees.
    a. considers
    b. None of the mentioned
    c. deletes
    d. ignores
  10. If external fragmentation is not allowed in a file allocation system, which of the following allocation scheme(s) can be utilized? 
    I. Contiguous
    II. Linked
    III. Indexed
    a. Ill only
    b. I and III only
    c. II only
    d. II and III only
  11. A file consists of logical records with a fixed length, which allow programs to read and write records quickly, without any specific order.
    a. All of the above.
    b. Direct Access Methods
    c. Logical Access Methods
    d. Sequential Access Methods
  12. Which of the following disk-scheduling methods is most likely to lead to starvation for requests on inner or outer cylinders?
    a. SCAN
    b. b-SCAN
    c. SSTF
    d. FCFS
    e. C-SCAN




  13. RAID can be implemented in__________.
    a. Bus adapter
    b. None of the above.
    c. Host bus adapter hardware
    d. Host adapter
  14. ______is the time for the disk arm to move the heads to the cylinder containing the desired sector.
    a. Latency
    b. Rotational latency
    c. None of the above.
    d. Seek time
  15. ______scheduling may cause starvation of some requests.
    a. SSTF
    b. C-SCAN
    c. FCFS
    d. SCAN
  16. Consider disk has 200 tracks. Say there is a request 15, 20, 44, 82, 141, 180, and 190. The Using CSCAN scheduling find the total seek time if the read/write head is at 40 and moving towards bigger number.
    a. 180
    b. 343
    c. 312
    d. 223




  17. Given a priori information about the number of resources of each type that maybe requested for each process. it is possible to construct an algorithm that ensures that the system will never enter a deadlock state
    a. minimum
    b. approximate
    c. maximum
    d. average
  18. A computer system has 6 tape drives, with ‘n’ processes competing for them. Each process may need 3 tape drives. The maximum value of ‘n’ for which the system is guaranteed to be deadlock free is?
    a. 3
    b. 4 
    c. 2
    d. 1
  19. For an effective operating system, when to check for deadlock?
    a. at fixed time intervals
    b. randomly
    c. every time a resource request is made at fixed time intervals
    d. every time a resource request is made
  20. Each request requires that the system consider the satisfied or must wait to avoid a future possible deadlock. to decide whether the current request can be
    a. processes that have previously been in the system
    b. resources currently allocated to each process
    c. resources currently available
    d. future requests and releases of each process

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Quiz – 1

  1. The address of the next instruction to be executed by the current process is provided by the
    a. Program counter
    b. CPU registers
    c. Pipe
    d. Process stack
  2. The address of the next instruction to be executed by the current process is provided by the
    a. CPU registers
    b. Process stack
    c. Pipe
    d. Program counter
  3. Which of the following do not belong to queues for processes?
    a. Job Queue
    b. PCB queue
    c. Ready Queue
    d. Device Queue
  4. In a 16KB memory there are ___________ address lines and __________ data lines
    a. 8,16
    b. 16,16
    c. 16,8
    d. 14,8




  5. In UNIX operating system __________ Interacts with hardware
    a. Kernel
    b. Software
    c. User
    d. Shell
  6. What is a medium-term scheduler?
    a. It selects which process has to be brought into the ready queue
    b. None of the other options
    c. It selects which process has to be executed next and allocates CPU
    d. It selects which process to remove from memory by swapping
  7. Consider 5 processes whose Arrival time and CPU Burst time is as follows (Process no: Arrival time: Burst time: priority):
    P1:0, 3, 1
    P2 2,3, 2
    P3:3, 2, 1
    P4: 5,5,3
    P5: 6,9,2
    Assume that the processes are scheduled using priority (Non-preemptive and process with highest priority number is given higher priority) scheduling algorithm. The average waiting and turaround time is
    a. 6.00, 11.20
    b. 6.40, 11.60
    c. 4.60, 9.40
    d. 4.80, 9.20
  8. The part of a program in which shared memory is accessed and which is to be executed indivisibly is called.
    a. critical section
    b. semaphores
    c. mutual exclusion
    d. directory




  9. Consider 5 processes whose Arrival time and CPU Burst time is as follows (Process no: Arrival time: Burst time):
    P1:0,6
    P2:2.4
    P3:3,2
    P4:5,5
    P5:6,9
    Assume that the processes are scheduled using Round Robin (RR) scheduling algorithm with time quantum 3. The average waiting and turaround time is
    a. 8.60, 13.60
    b. 8.00, 13.20
    c. 8.40, 13.80
    d. 8.20, 13.40
  10. The processes that are residing in main memory and are ready and waiting to execute are kept on a list called
    a. process queue
    b. job queue
    c. ready queue
    d. execution queue
  11. Which algorithm is defined in Time quantum?
    a. round robin scheduling algorithm
    b. priority scheduling algorithm
    c. multilevel queue scheduling algorithm
    d. shortest job scheduling algorithm
  12. Consider 5 processes whose Arrival time and CPU Burst time is as follows (Process no: Arrival time: Burst time):
    P1:0,3
    P2:2,3
    P3:3,2
    P4:5,5
    P5:6,9
    Assume that the processes are scheduled using SJF (Non-preemptive) scheduling algorithm. The average waiting and turaround time is
    a. 2.60, 7.00
    b. 3.60, 7.00
    c. 2.60, 7.05
    d. 2.65, 7.00




  13. The pre-emptive scheduling algorithm is
    a. FCFS Scheduling
    b. SJF Scheduling
    c. Round Robin
    d. Priority Scheduling
  14. Assume that there are 3 processes P1, P2 and P3 have arrived 5 milliseconds after the system has started at the same time. Their burst times are 5,3 and 4 respectively. If they are processed in SJN principle, when is the process P3 is completed?
    a. 8
    b. 12
    c. 7
    d. 11
  15. Round robin scheduling falls under the category of _____________
    a. None of the mentioned
    b. All of the mentioned
    c. Preemptive scheduling
    d. Non-preemptive scheduling
  16. Pre-emptive scheduling, is the strategy of temporarily suspending a running process
    a. to allow starving process to run
    b. when it requests I/O
    c. none of the above
    d. before the CPU time slice expires




  17. In UNIX operating system _________ process is started after booting the system
    a. shell
    b. Parent
    c. init
    d. command
  18. The number of processes completed per unit time is known as __________
    a. Efficiency
    b. Capacity
    c. Throughput
    d. Output
  19. Registers are __________
    a. Low speed high capacity
    b. High speed high capacity
    c. Low speed low capacity
    d. High speed low capacity
  20. Which of the following is not present inside the Task Control Block
    a. CPU registers
    b. Scheduling information
    c. OS information
    d. Accounting information

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