set-2
51. Which of the following is true?
Overlays are used to increase the size of physical memory
Overlays are used to increase the logical address space
When overlays are used, the size of a process is not limited to the size of physical memory
Overlays are used whenever the physical address space is smaller than the logical address space
52. In partitioned memory allocation scheme:
Best-fit algorithm is always better than the first-fit algorithm
First-fit algorithm is always better than the best-fit algorithm
Superiority of the first-fit and best-fit algorithms depends on the sequence of memory requests
None of the above
53. Cascading termination refers to the termination of all child processes before the parent terminates:
Normally
Normally or abnormally
Abnormally
None of the above
54. For implementing a multiprogramming operating system:
Special support from the processor is essential
Special support from the processor is not essential
Cache memory must be available
More than one processor must be available
55. Consider a system having ‘m’ resources of the same type. These resources are shared by 3 processes A, B, C, which have time demands of 3, 4, 6 respectively. The minimum value of ‘m’ that ensures that deadlock will never occur is:
11
12
13
14
56. A system has 3 processes sharing 4 resources. If each process needs a maximum of 2 units, then deadlock:
Can never occur
Has to occur
May occur
None of the above
57. ‘m’ processes share ‘n’ resources of the same type. The maximum need of each process does not exceed ‘n’, and the sum of all their maximum needs is always less than . In this setup, deadlock:
Can never occur
Has to occur
May occur
None of the above
58. A process refers to 5 pages, A, B, C, D, and E, in the order: A; B; C; D; A; E; B; C; D; E. If the page replacement algorithm is FIFO, the number of page faults with an empty internal store of 3 frames is:
8
10
9
7
59. Distributed systems should:
Meet prescribed time constraints
Aim for better system utilization
Aim for better resource sharing
Aim for low system overhead
60. The main function of shared memory is:
Use primary memory efficiently
Do inter-process communication
Do intra-process communication
None of the above
61. Which of the following is the most suitable scheduling scheme in a real-time operating system?
Round-robin
Pre-emptive scheduling
First-come-first-serve
Random scheduling
62. ‘Aging’ is:
Keeping track of cache contents
Keeping track of what pages are currently residing in the memory
Keeping track of how many times a given page is referenced
Increasing the priority of jobs to ensure termination in a finite time
63. If there are 32 segments, each of size 1 Kbytes, then the logical address should have:
13 bits
14 bits
15 bits
16 bits
64. Disk requests come to a disk driver for cylinders in the order 10, 22, 20, 2, 40, 6, and 38 at a time when a disk drive is reading from cylinder 20. The seek time is 6 ms per cylinder. The total seek time, if the disk arm scheduling algorithm is first-come-first-served, is:
360 ms
850 ms
900 ms
None of the above
65. A certain moving arm disk storage with one head has the following specifications:
Number of tracks/recording surface = 200
Disk rotation speed = 2400 rpm
Track storage capacity = 62500 bits The average latency time (assume that the head can move from one track to another only by traversing the entire track) is:
2.5 s
2.9 s
3.1 s
3.6 s
66. Memory protection is normally done by the:
Operating system
Compiler
Processor and the associated hardware
User program
67. Which of the following scheduling algorithms gives the minimum average waiting time?
FCFS
SJF
Round-robin
Priority
68. In a paged segmented scheme of memory management, the segment table itself must have a page table because:
The segment table is often too large to fit in one page
Each segment is spread over a number of pages
Segment tables point to page tables and not to the physical location of the segment
The processor’s description base register points to a page table
69. Which of the following page replacement algorithms suffers from Belady’s anomaly?
Optimal replacement
FIFO
LRU
Both optimal replacement and FIFO
70. Which of the following scheduling policies is well suited for a time-shared operating system?
Shortest job first
First come first serve
Round robin
Elevator
71. The address sequence generated by tracing a particular program executing in a pure demand paging system with 100 records per page, with 1 free main memory frame is recorded as follows. What is the number of page faults?
0100, 0200, 0430, 0499, 0510, 0530, 0560, 0120, 0220, 0240, 0260, 0320, 0370.
13
8
7
10
72. A computer system has 4 K word cache organized in a block-set-associative manner, with 4 blocks per set, 64 words per block. The number of bits in SET and WORD fields of the main memory address format is:
14, 4
6, 4
7, 2
4, 6
73. A memory page containing a heavily used variable that was initialized very early and is in constant use is removed when the page replacement algorithm is used:
LRU
FIFO
LFU
None of the above
74. A demand paging system, with the page table held in registers, takes 5 ms to service a page fault if an empty page is available, or if the page to be replaced is not dirty. It takes 15 ms if the replaced page is dirty. Memory access time is 1 microsecond. Assume we want an effective access time of 2 microseconds and that the page to be replaced is dirty 60% of the time. What is the approximate maximum acceptable page fault rate to meet this access time requirement?
0.1%
1.0%
2.5%
0.01%
75. Memory protection is normally done by the:
Operating system
Compiler
Processor and the associated hardware
User program
76. Which of the following scheduling algorithms gives the minimum average waiting time?
FCFS
SJF
Round-robin
Priority
77. In a paged segmented scheme of memory management, the segment table itself must have a page table because:
The segment table is often too large to fit in one page
Each segment is spread over a number of pages
Segment tables point to page tables and not to the physical location of the segment
The processor’s description base register points to a page table
78. Which of the following page replacement algorithms suffers from Belady’s anomaly?
Optimal replacement
FIFO
LRU
Both optimal replacement and FIFO
79. Which of the following scheduling policies is well suited for a time-shared operating system?
Shortest job first
First come first serve
Round robin
Elevator
80. The address sequence generated by tracing a particular program executing in a pure demand paging system with 100 records per page, with 1 free main memory frame is recorded as follows. What is the number of page faults?
0100, 0200, 0430, 0499, 0510, 0530, 0560, 0120, 0220, 0240, 0260, 0320, 0370.
13
8
7
10
81. A computer system has 4 K word cache organized in a block-set-associative manner, with 4 blocks per set, 64 words per block. The number of bits in SET and WORD fields of the main memory address format is:
14, 4
6, 4
7, 2
4, 6
82. A memory page containing a heavily used variable that was initialized very early and is in constant use is removed when the page replacement algorithm is used:
LRU
FIFO
LFU
None of the above
83. A demand paging system, with the page table held in registers, takes 5 ms to service a page fault if an empty page is available, or if the page to be replaced is not dirty. It takes 15 ms if the replaced page is dirty. Memory access time is 1 microsecond. Assume we want an effective access time of 2 microseconds and that the page to be replaced is dirty 60% of the time. What is the approximate maximum acceptable page fault rate to meet this access time requirement?
0.1%
1.0%
2.5%
0.01%
84. Trojan-Horse programs:
Are legitimate programs that allow unauthorized access
Do not usually work
Are hidden programs that do not show up on the system
Usually are immediately discovered
85. Page stealing:
Is a sign of an efficient system
Is taking page frames from other working sets
Should be the tuning goal
Is taking larger disk spaces for pages paged out
86. In virtual memory systems, Dynamic address translation:
Is the hardware necessary to implement paging
Stores pages at a specific location on disk
Is useless when swapping is used
Is part of the operating system paging algorithm
87. The garbage collector:
Prevents fragmentation from occurring
Is mostly used with fixed partitions
Collects fragmented areas of memory
Is critical for efficient virtual memory system
88. Page-map table is:
A data file
Used for address translation
A directory
All of the above
89. Which of the following rules out the use of GO TO?
Flowchart
Nassi-Shneiderman diagram
HIPO-DIAGRAMS
All of the above
90. Which of the following is a phase of a compilation process?
Lexical analysis
Both of the above
Code generation
Static analysis
91. A computer cannot “boot” if it does not have the:
Computer
Operating system
Loader
Assembler
92. Which of the following is a measure to test how good or bad a modular design is:
Module strength
Static analysis
Module coupling
All of the above
93. Which of the following types of software must you have in main memory in order to use your keyboard?
Word processing
Applications
Systems
Spreadsheet
94. If you want to execute more than one program at a time, the system software you are using must be capable of:
Word processing
Compiling
Virtual memory
Multitasking
95. Which of the following is a type of systems software used on microcomputers?
Apple DOS
PC-DOS
MS-DOS
All of the above
96. Which of the following is helpful in evaluating applications software that will best suit your needs?
Recommendations by other users
Objective software reviews
Computer magazines
All of the above
97. Which of the following are loaded into main memory when the computer is booted?
Internal command instructions
Utility programs
External command instructions
Word processing instructions
98. Which of the following software types is used to simplify using systems software?
Spreadsheet
Time sharing
Operating environment
Multitasking
99. Which of the following is not applications software?
Word processing
UNIX
Spreadsheet
Desktop publishing
100. Which of the following types of software should you use if you often need to create, edit, and print documents?
Word processing
UNIX
Spreadsheet
Desktop publishing
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