Quiznetik

Operating System (OS) | Set 6

1. A block device transfers

Correct : B. block of bytes as a unit

2. What is a dedicated device?

Correct : A. opposite to a sharable device

3. A keyboard is an example of a device that is accessed through a                      interface.

Correct : C. character stream

4. In polling

Correct : A. busy – wait cycles wait for i/o from device

5. A non blocking system call

Correct : B. does not halt the execution of the application

6. An asynchronous call

Correct : A. returns immediately, without waiting for the i/o to complete

7. Buffering is done to

Correct : D. all of the mentioned

8. Caching is                  spooling.

Correct : B. not the same as

9. Caching

Correct : A. holds a copy of the data

10. Spooling

Correct : C. holds the only copy of the data

11. The                  keeps state information about the use of I/O components.

Correct : C. kernel

12. The kernel data structures include

Correct : B. open file table

13. If the number of cycles spent busy – waiting is not excessive, then

Correct : B. programmed i/o is more efficient than interrupt driven i/o

14. A                  is a full duplex connection between a device driver and a user level process.

Correct : C. stream

15. The first linux kernel which supports the SMP hardware?

Correct : D. linux 2.0

16. Which one of the following linux file system does not support journaling feature?

Correct : A. ext2

17. Which binary format is supported by linux?

Correct : C. both a.out and elf

18. Which one of the following bootloader is not used by linux?

Correct : C. ntldr

19. The first process launched by the linux kernel is

Correct : A. init process

20. Which desktop environment is not used in any linux distribution?

Correct : D. none of the mentioned

21. Standard set of functions through which interacts with kernel is defined by

Correct : A. system libraries

22. What is Linux?

Correct : D. multi user, multitasking

23. Which one of the following is not a linux distribution?

Correct : D. multics

24. Which one of the following is not shared by threads?

Correct : C. both program counter and stack

25. A process can be

Correct : C. both single threaded and multithreaded

26. If one thread opens a file with read privileges then

Correct : B. other threads in the same process can also read from that file

27. The time required to create a new thread in an existing process is

Correct : B. less than the time required to create a new process

28. When the event for which a thread is blocked occurs?

Correct : A. thread moves to the ready queue

29. The jacketing technique is used to

Correct : A. convert a blocking system call into non blocking system call

30. Termination of the process terminates

Correct : C. all threads within the process

31. Which one of the following is not a valid state of a thread?

Correct : B. parsing

32. The register context and stacks of a thread are deallocated when the thread?

Correct : A. terminates

33. Thread synchronization is required because

Correct : D. all of the mentioned

34. A thread is also called

Correct : A. light weight process(lwp)

35. A thread shares its resources(like data section, code section, open files, signals) with

Correct : C. other threads that belong to the same process

36. Resource sharing helps

Correct : D. all of the mentioned

37. Multithreading on a multi – CPU machine

Correct : B. has a single thread of execution

38. A process having multiple threads of control implies

Correct : A. it can do more than one task at a time

39. The kernel is                of user threads.

Correct : C. unaware of

40. Because the kernel thread management is done by the Operating System itself

Correct : B. kernel threads are slower to create than user threads

41. If a kernel thread performs a blocking system call,

Correct : A. the kernel can schedule another thread in the application for execution

42. Which of the following is FALSE?

Correct : D. blocking one kernel level thread blocks all other related threads

43. The model in which one kernel thread is mapped to many user-level threads is called

Correct : A. many to one model

44. The model in which one user-level thread is mapped to many kernel level threads is called

Correct : B. one to many model

45. In the Many to One model, if a thread makes a blocking system call

Correct : A. the entire process will be blocked

46. In the Many to One model, multiple threads are unable to run in parallel on multiprocessors because of

Correct : A. only one thread can access the kernel at a time

47. The One to One model allows

Correct : A. increased concurrency

48. Which of the following is the drawback of the One to One Model?

Correct : D. creating a user thread requires creating the corresponding kernel thread

49. When is the Many to One model at an advantage?

Correct : A. when the program does not need multithreading

50. In the Many to Many model true concurrency cannot be gained because

Correct : B. other threads are allowed to run

51. Which of the following system calls does not return control to the calling point, on termination?

Correct : B. exec

52. Which of the following system calls transforms executable binary file into a process?

Correct : B. exec

53. Which of the following calls never returns an error?

Correct : A. getpid

54. A fork system call will fail if

Correct : B. the limit on the maximum number of processes in the system would be executed

55. If a thread invokes the exec system call

Correct : B. the program specified in the parameter to exec will replace the entire process

56. If exec is called immediately after forking

Correct : A. the program specified in the parameter to exec will replace the entire process

57. If a process does not call exec after forking

Correct : B. all the threads should be duplicated

58. What is Thread cancellation?

Correct : C. the task of terminating a thread before it has completed

59. When a web page is loading, and the user presses a button on the browser to stop loading the page?

Correct : D. the thread loading the page is cancelled

60. When one thread immediately terminates the target thread, it is called

Correct : A. asynchronous cancellation

61. When the target thread periodically checks if it should terminate and terminates itself in an orderly manner, it is called?

Correct : D. deferred cancellation

62. Cancelling a thread asynchronously

Correct : B. may not free each resource

63. Cancellation point is the point where

Correct : B. the thread can be cancelled safely

64. If multiple threads are concurrently searching through a database and one thread returns the result then the remaining threads must be

Correct : B. cancelled

65. Signals that occur at the same time, are presented to the process

Correct : B. one at a time, in no particular order

66. Which of the following is not TRUE?

Correct : C. a field is updated in the signal table when the signal is sent

67. Signals of a given type

Correct : B. are all sent as one

68. The three ways in which a process responds to a signal are

Correct : D. all of the mentioned

69. Signals are identified by

Correct : A. signal identifiers

70. When a process blocks the receipt of certain signals?

Correct : A. the signals are delivered

71. The                maintains pending and blocked bit vectors in the context of each process.

Correct : D. kernel

72. In UNIX, the set of masked signals can be set or cleared using the                  function.

Correct : C. sigprocmask

73. The usefulness of signals as a general inter process communication mechanism is limited because

Correct : C. they cannot carry information directly

74. The usual effect of abnormal termination of a program is

Correct : A. core dump file generation

75. In most cases, if a process is sent a signal while it is executing a system call

Correct : C. the signal has no effect until the system call completes

76. A process can never be sure that a signal it has sent

Correct : B. has not been lost

77. In UNIX, the                              system call is used to send a signal.

Correct : C. kill

78. Thread pools are useful when

Correct : A. when we need to limit the number of threads running in the application at the same time

79. Instead of starting a new thread for every task to execute concurrently, the task can be passed to a

Correct : B. thread pool

80. Each connection arriving at multi threaded servers via network is generally

Correct : B. is wrapped as a task and passed on to a thread pool

81. What is the idea behind thread pools?

Correct : A. a number of threads are created at process startup and placed in a pool where they sit and wait for work

82. If the thread pool contains no available thread

Correct : D. the server waits until one becomes free

83. Thread pools help in

Correct : C. faster servicing of requests with an existing thread rather than waiting to create a new thread

84. The number of the threads in the pool can be decided on factors such as

Correct : D. all of the mentioned

85. The swaps processes in and out of the memory.

Correct : A. Memory Manager

86. The address generated by the CPU is referred to as

Correct : B. Logical Address

87. Operating System maintains the page table for

Correct : A. each process

88. What is operating system?

Correct : D. all of the mentioned

89. In a time-sharing operating system, when the time slot given to a process is completed, the process goes from the running state to the:

Correct : B. ready state

90. In virtual memory, which is not a page replacement algorithm ?

Correct : B. BFS

91. Thrashing the CPU utilization.

Correct : C. decreases

92. Mutual exclusion can be provided by the

Correct : C. both mutex locks and binary

93. A parent process calling system call will be suspended until children processes terminate.

Correct : A. wait

94. The child process completes execution, but the parent keeps executing, then the child process is known as

Correct : B. Zombie

95. When the process issues an I/O request

Correct : A. It is placed in an I/O queue

96. Which one of the following is the deadlock avoidance algorithm?

Correct : A. banker’s algorithm

97. File type can be represented by

Correct : B. file extension

98. Which of the following are the two parts of the file name?

Correct : C. extension & name

99. Which of the following are forms of malicious attack?

Correct : D. All of the mentioned

100. From the following, which is not a common file permission?

Correct : C. Stop