Thursday, October 1, 2009

Multiple Choice Questions On Operating System Part-4

1) Round robin scheduling is essentially the preemptive version of ________.
2 Shortest job first
3 Shortes remaining
4 Longest time first
Right Ans ) 1

2) A page fault occurs
1 when the page is not in the memory
2 when the page is in the memory
3 when the process enters the blocked state
4 when the process is in the ready state
Right Ans ) 1

3) Which of the following will determine your choice of systems software for your computer ?
1 Is the applications software you want to use compatible with it ?
2 Is it expensive ?
3 Is it compatible with your hardware ?
4 Both 1 and 3
Right Ans ) 4

4) 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 _________ .
1 Semaphore
2 Deadlock
3 Signal
4 Interrupt
Right Ans ) 2

5) What is a shell ?
1 It is a hardware component
2 It is a command interpreter
3 It is a part in compiler
4 It is a tool in CPU scheduling
Right Ans ) 2

6) Routine is not loaded until it is called. All routines are kept on disk in a relocatable load format. The main program is loaded into memory & is executed. This type of loading is called _________
1 Static loading
2 Dynamic loading
3 Dynamic linking
4 Overlays
Right Ans ) 3

7) In the blocked state
1 the processes waiting for I/O are found
2 the process which is running is found
3 the processes waiting for the processor are found
4 none of the above
Right Ans ) 1

8) What is the memory from 1K - 640K called ?
1 Extended Memory
2 Normal Memory
3 Low Memory
4 Conventional Memory
Right Ans ) 4

9) Virtual memory is __________.
1 An extremely large main memory
2 An extremely large secondary memory
3 An illusion of extremely large main memory
4 A type of memory used in super computers.
Right Ans ) 3

10) The process related to process control, file management, device management, information about system and communication that is requested by any higher level language can be performed by __________.
1 Editors
2 Compilers
3 System Call
4 Caching
Right Ans ) 3

11) If the Disk head is located initially at 32, find the number of disk moves required with FCFS if the disk queue of I/O blocks requests are 98,37,14,124,65,67.
1 310
2 324
3 315
4 321
Right Ans ) 4

12) Multiprogramming systems ________.
1 Are easier to develop than single programming systems
2 Execute each job faster
3 Execute more jobs in the same time
4 Are used only on large main frame computers
Right Ans ) 3

13) Which is not the state of the process ?
1 Blocked
2 Running
3 Ready
4 Privileged
Right Ans ) 4

14) The solution to Critical Section Problem is : Mutual Exclusion, Progress and Bounded Waiting.
1 The statement is false
2 The statement is true.
3 The statement is contradictory.
4 None of the above
Right Ans ) 2

15) The problem of thrashing is effected scientifically by ________.
1 Program structure
2 Program size
3 Primary storage size
4 None of the above
Right Ans ) 1

16) The state of a process after it encounters an I/O instruction is __________.
1 Ready
2 Blocked/Waiting
3 Idle
4 Running
Right Ans ) 2

17) The number of processes completed per unit time is known as __________.
1 Output
2 Throughput
3 Efficiency
4 Capacity
Right Ans ) 2

18) _________ is the situation in which a process is waiting on another process,which is also waiting on another process ... which is waiting on the first process. None of the processes involved in this circular wait are making progress.
1 Deadlock
2 Starvation
3 Dormant
4 None of the above
Right Ans ) 1

19) Which of the following file name extension suggests that the file is Backup copy of another file ?
Right Ans ) 4

20) Which technique was introduced because a single job could not keep both the CPU and the I/O devices busy?
1 Time-sharing
2 SPOOLing
3 Preemptive scheduling
4 Multiprogramming
Right Ans ) 4

21) A critical region
1 is a piece of code which only one process executes at a time
2 is a region prone to deadlock
3 is a piece of code which only a finite number of processes execute
4 is found only in Windows NT operation system
Right Ans ) 1

22) The mechanism that bring a page into memory only when it is needed is called _____________
1 Segmentation
2 Fragmentation
3 Demand Paging
4 Page Replacement
Right Ans ) 3

23) PCB =
1 Program Control Block
2 Process Control Block
3 Process Communication Block
4 None of the above
Right Ans ) 2

24) FIFO scheduling is ________.
1 Preemptive Scheduling
2 Non Preemptive Scheduling
3 Deadline Scheduling
4 Fair share scheduling
Right Ans ) 2

25) Switching the CPU to another Process requires to save state of the old process and loading new process state is called as __________.
1 Process Blocking
2 Context Switch
3 Time Sharing
4 None of the above
Right Ans ) 2

26) Which directory implementation is used in most Operating System?
1 Single level directory structure
2 Two level directory structure
3 Tree directory structure
4 Acyclic directory structure
Right Ans ) 3

27) The Banker¿s algorithm is used
1 to prevent deadlock in operating systems
2 to detect deadlock in operating systems
3 to rectify a deadlocked state
4 none of the above
Right Ans ) 1

28) A thread
1 is a lightweight process where the context switching is low
2 is a lightweight process where the context swithching is high
3 is used to speed up paging
4 none of the above
Right Ans ) 1

29) ______ is a high level abstraction over Semaphore.
1 Shared memory
2 Message passing
3 Monitor
4 Mutual exclusion
Right Ans ) 3

30) A tree sturctured file directory system
1 allows easy storage and retrieval of file names
2 is a much debated unecessary feature
3 is not essential when we have millions of files
4 none of the above
Right Ans ) 1


  1. questionis good but we need some explanation...

  2. Dheeraj Tyagi - questions can help a lot

  3. these are the basic questions,need some high level questions,but these all are very good questions for gaining basic knowledge........

  4. good me to recall OS fundamentals..

  5. it is good but we need explain.
    thank you

  6. Thanx.....
    good questions for the preparation point of view. plz post some more questions.

  7. Its good to refresh the mind with all these questions but these are basic concepts of OS and I would like to suggest you to post more and tricky ones.

  8. excellent compostion ..... I feel answer to question 6 is option 2

  9. @sndpj > Thanks a lot .. really helpful

  10. Answer of Q 27 should be (4) because the bnkar's algo is a deadlock avoidance scheme.

  11. nice questions........
    but some should be like company placemnet

  12. good questions and we need some critical questions for preparation

  13. really good question but i need some more question related to the scheduling.....with explanation....

  14. nice questions bt dere iz sum contradiction wid q no 6. I think the ans shud be dynamic loading instead of dynamic linking

  15. i m confused with the answer of 6. Can any one explain why it is not dynamic loading.
    thanks in advance

  16. excellent.............its very help full......thank u very much

  17. very nice questions for a fast brush up of concepts

  18. we need more question. and these question are very helpful for me....................

  19. Q6 - right answer is 2 [Dynamic Loading]
    Q7 - right answer is 1 [In the blocked state
    the processes waiting for I/O are found]

  20. nice... but some questions need explanation

  21. ya thank you buddy...prepare many more questions like this.

  22. it can be much better means some more questions ????

  23. thank' helping us.......

  24. thanks question was good..
    if any query call at 7276481825(gaurav c-dac)

  25. nice basic more questins like these nd related to schedulig algos and resource sharing concept.

  26. THANKS!!! for that but i want more difficult question & a lot.

  27. really questions are nice but there is a small quantity we need more and more questions for compitions..

  28. plz give me more question on paging & scheduling these very helpful for me

  29. Q:20 spooling is th rgt answr.

  30. Thank you very much for reminding OS

  31. very good,basic idea of O.S is fresh again,think you

  32. Nice list of questions.Thanks for sharing.
    Software Company India

  33. Thank you..If u give some explanation along's help a lot. But nice work done.

  34. this was more than enough. Super thanks Super like!

    I will google up explanations if needed, Dont know why people want it all cooked up.!

    super help!

  35. The Banker¿s algorithm is used

    in deadlock avoidance not ans 1

    ans is 4 (none of these)
    There is a slight difference between deadlock avoidance and prevention

  36.'s very helpful to me!!!!

  37. These are vry basic..need some advance level que.

  38. please post some abstract questions which are difficult to tackle all at once. Also provide solutions to those questions which are tricky.

  39. thanx for improving my confidence in o.s

  40. thnxx gud questions as per thoretical portion......need some numericals on memory managemnt

  41. Thank for Knowledge improvement
    More Sonyabapu

  42. v helping ..good material thnkx

  43. Bankers algo, is used for avoidance of deadlock, not to prevent it.Is question 27 answer right ???????

  44. it's so help full for because i searching this kind of question related to programmer

    Thanks yaar

  45. Good questions, they are important question in OS

  46. questions are good...but it is not sufficient for any exam..

  47. thanks these questions are very good. Please posts some more questiones for cdac entrance exams point of view.

  48. Good questions. But please provide explanations to your answers and links to reading material. Btw which is the best site to read about operating systems?