Quiznetik

Operating System (OS) | Set 4

1. Which is the process of invoking the wait

Correct : A. transaction

2. Write ahead logging is a way

Correct : D. all of the mentioned

3. The system periodically performs checkpoints that consists of the following operation(s)

Correct : D. all of the mentioned

4. A locking protocol is one that

Correct : C. governs how locks are acquired and released

5. The two phase locking protocol consists of

Correct : A. growing & shrinking phase

6. The growing phase is a phase in which?

Correct : A. a transaction may obtain locks, but does not release any

7. What is a reusable resource?

Correct : A. that can be used by one process at a time and is not depleted by that use

8. Which of the following condition is required for a deadlock to be possible?

Correct : D. all of the mentioned

9. Which of the following concurrency control protocols ensure both conflict serializability and freedom from deadlock?

Correct : A. the system can allocate resources to each process in some order and still avoid a deadlock

10. The circular wait condition can be prevented by

Correct : A. defining a linear ordering of resource types

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

Correct : A. banker’s algorithm

12. What is the drawback of banker’s algorithm?

Correct : D. all of the mentioned

13. For an effective operating system, when to check for deadlock?

Correct : C. every time a resource request is made at fixed time intervals

14. A problem encountered in multitasking when a process is perpetually denied necessary resources is called

Correct : B. starvation

15. Which one of the following is a visual ( mathematical ) way to determine the deadlock occurrence?

Correct : A. resource allocation graph

16. To avoid deadlock

Correct : A. there must be a fixed number of resources to allocate

17. The number of resources requested by a process

Correct : C. must not exceed the total number of resources available in the system

18. The request and release of resources are

Correct : C. system calls

19. For a deadlock to arise, which of the following conditions must hold simultaneously?

Correct : D. all of the mentioned

20. For non sharable resources like a printer, mutual exclusion

Correct : A. must exist

21. The disadvantage of a process being allocated all its resources before beginning its execution is

Correct : B. low resource utilization

22. Each request requires that the system consider the                            to decide whether the current request can be satisfied or must wait to avoid a future possible deadlock.

Correct : A. resources currently available

23. A deadlock avoidance algorithm dynamically examines the                      to ensure that a circular wait condition can never exist.

Correct : A. resource allocation state

24. A state is safe, if

Correct : B. the system can allocate resources to each process in some order and still avoid a deadlock

25. A system is in a safe state only if there exists a

Correct : C. safe sequence

26. All unsafe states are

Correct : B. not deadlocks

27. If no cycle exists in the resource allocation graph

Correct : B. then the system will be in a safe state

28. The resource allocation graph is not applicable to a resource allocation system

Correct : A. with multiple instances of each resource type

29. The data structures available in the Banker’s algorithm are

Correct : D. all of the mentioned

30. The content of the matrix Need is

Correct : C. max – allocation

31. The wait-for graph is a deadlock detection algorithm that is applicable when

Correct : A. all resources have a single instance

32. An edge from process Pi to Pj in a wait for graph indicates that

Correct : A. pi is waiting for pj to release a resource that pi needs

33. If the wait for graph contains a cycle

Correct : B. then a deadlock exists

34. If deadlocks occur frequently, the detection algorithm must be invoked

Correct : B. frequently

35. What is the disadvantage of invoking the detection algorithm for every request?

Correct : C. considerable overhead in computation time

36. A deadlock eventually cripples system throughput and will cause the CPU utilization to

Correct : B. drop

37. Every time a request for allocation cannot be granted immediately, the detection algorithm is invoked. This will help identify

Correct : A. the set of processes that have been deadlocked

38. 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?

Correct : A. 2

39. A system has 3 processes sharing 4 resources. If each process needs a maximum of 2 units then, deadlock

Correct : A. can never occur

40. ‘m’ processes share ‘n’ resources of the same type. The maximum need of each process doesn’t exceed ‘n’ and the sum of all their maximum needs is always less than m+n. In this setup, deadlock

Correct : A. can never occur

41. A deadlock can be broken by

Correct : A. abort one or more processes to break the circular wait

42. The two ways of aborting processes and eliminating deadlocks are

Correct : C. abort one process at a time until the deadlock cycle is eliminated

43. Those processes should be aborted on occurrence of a deadlock, the termination of which?

Correct : B. incurs minimum cost

44. The process to be aborted is chosen on the basis of the following factors?

Correct : D. all of the mentioned

45. Cost factors for process termination include

Correct : C. amount of time a deadlocked process has thus far consumed during its execution

46. If we preempt a resource from a process, the process cannot continue with its normal execution and it must be

Correct : B. rolled back

47. To                to a safe state, the system needs to keep more information about the states of processes.

Correct : B. roll back the process

48. If the resources are always preempted from the same process                      can occur.

Correct : D. starvation

49. What is the solution to starvation?

Correct : A. the number of rollbacks must be included in the cost factor

50. What is Address Binding?

Correct : D. a mapping from one address space to another

51. Binding of instructions and data to memory addresses can be done at

Correct : D. all of the mentioned

52. If the process can be moved during its execution from one memory segment to another, then binding must be

Correct : A. delayed until run time

53. What is Dynamic loading?

Correct : B. loading a routine only when it is called

54. What is the advantage of dynamic loading?

Correct : B. an unused routine is never loaded

55. The idea of overlays is to

Correct : D. all of the mentioned

56. The                        must design and program the overlay structure.

Correct : A. programmer

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

Correct : A. memory manager

58. If binding is done at assembly or load time, then the process            be moved to different locations after being swapped out and in again.

Correct : C. can never

59. In a system that does not support swapping

Correct : A. the compiler normally binds symbolic addresses (variables) to relocatable addresses

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

Correct : B. logical address

61. The address loaded into the memory address register of the memory is referred to as

Correct : A. physical address

62. The run time mapping from virtual to physical addresses is done by a hardware device called the

Correct : B. memory management unit

63. The size of a process is limited to the size of

Correct : A. physical memory

64. If execution time binding is being used, then a process              be swapped to a different memory space.

Correct : D. may

65. Swapping requires a

Correct : D. backing store

66. The backing store is generally a

Correct : D. all of the mentioned

67. The                  consists of all processes whose memory images are in the backing store or in memory and are ready to run.

Correct : B. ready queue

68. The                    time in a swap out of a running process and swap in of a new process into the memory is very high.

Correct : A. context – switch

69. Swapping                be done when a process has pending I/O, or has to execute I/O operations only into operating system buffers.

Correct : C. must never

70. Swap space is allocated

Correct : A. as a chunk of disk

71. CPU fetches the instruction from memory according to the value of

Correct : A. program counter

72. A memory buffer used to accommodate a speed differential is called

Correct : B. cache

73. Which one of the following is the address generated by CPU?

Correct : C. logical address

74. Run time mapping from virtual to physical address is done by

Correct : A. memory management unit

75. Memory management technique in which system stores and retrieves data from secondary storage for use in main memory is called?

Correct : B. paging

76. The address of a page table in memory is pointed by

Correct : B. page table base register

77. Program always deals with

Correct : A. logical address

78. The page table contains

Correct : A. base address of each page in physical memory

79. What is compaction?

Correct : C. a technique for overcoming external fragmentation

80. Operating System maintains the page table for

Correct : A. each process

81. The main memory accommodates

Correct : A. operating system

82. What is the operating system?

Correct : C. either low or high memory (depending on the location of interrupt vector)

83. In contiguous memory allocation

Correct : A. each process is contained in a single contiguous section of memory

84. The relocation register helps in

Correct : C. to protect the address spaces of processes

85. The operating system and the other processes are protected from being modified by an already running process because

Correct : D. every address generated by the cpu is being checked against the relocation and limit registers

86. Transient operating system code is code that

Correct : B. comes and goes as needed

87. Using transient code,                the size of the operating system during program execution.

Correct : C. changes

88. In fixed size partition, the degree of multiprogramming is bounded by

Correct : A. the number of partitions

89. The first fit, best fit and worst fit are strategies to select a

Correct : C. free hole from a set of available holes

90. In internal fragmentation, memory is internal to a partition and

Correct : B. is not being used

91. A solution to the problem of external fragmentation is

Correct : A. compaction

92. Another solution to the problem of external fragmentation problem is to

Correct : A. permit the logical address space of a process to be noncontiguous

93. If relocation is static and is done at assembly or load time, compaction

Correct : A. cannot be done

94. The disadvantage of moving all process to one end of memory and all holes to the other direction, producing one large hole of available memory is

Correct : A. the cost incurred

95. External fragmentation will not occur when?

Correct : D. no matter which algorithm is used, it will always occur

96. Sometimes the overhead of keeping track of a hole might be

Correct : B. larger than the hole itself

97. When the memory allocated to a process is slightly larger than the process, then

Correct : A. internal fragmentation occurs

98. Physical memory is broken into fixed-sized blocks called

Correct : A. frames

99. Logical memory is broken into blocks of the same size called

Correct : B. pages

100. Every address generated by the CPU is divided into two parts. They are

Correct : B. page number & page offset