Operating System MCQ – Virtual Memory – Page Replacement Algorithms

This set of Operating System Multiple Choice Questions & Answers (MCQs) focuses on “Virtual Memory – Page Replacement Algorithms”.

1. Which of the following page replacement algorithms suffers from Belady’s Anomaly?
a) Optimal replacement
b) LRU
c) FIFO
d) Both optimal replacement and FIFO
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2. A process refers to 5 pages, A, B, C, D, E in the order : A, B, C, D, A, B, E, A, B, C, D, E. If the page replacement algorithm is FIFO, the number of page transfers with an empty internal store of 3 frames is?
a) 8
b) 10
c) 9
d) 7
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3. A process refers to 5 pages, A, B, C, D, E in the order : A, B, C, D, A, B, E, A, B, C, D, E. If the page replacement algorithm is FIFO, the number of page frames is increased to 4, then the number of page transfers ____________
a) decreases
b) increases
c) remains the same
d) none of the mentioned
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4. A memory page containing a heavily used variable that was initialized very early and is in constant use is removed, then the page replacement algorithm used is ____________
a) LRU
b) LFU
c) FIFO
d) None of the mentioned
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5. A virtual memory system uses First In First Out (FIFO) page replacement policy and allocates a fixed number of frames to a process. Consider the following statements.
P : Increasing the number of page frames allocated to a process sometimes increases the page fault rate
Q : Some programs do not exhibit locality of reference
Which of the following is TRUE?
a) Both P and Q are true, and Q is the reason for P
b) Both P and Q are true, but Q is not the reason for P
c) P is false but Q is true
d) Both P and Q are false
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6. Users _______ that their processes are running on a paged system.
a) are aware
b) are unaware
c) may unaware
d) none of the mentioned
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7. If no frames are free, _____ page transfer(s) is/are required.
a) one
b) two
c) three
d) four
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8. When a page is selected for replacement, and its modify bit is set ____________
a) the page is clean
b) the page has been modified since it was read in from the disk
c) the page is dirty
d) the page has been modified since it was read in from the disk & page is dirty
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9. The aim of creating page replacement algorithms is to ____________
a) replace pages faster
b) increase the page fault rate
c) decrease the page fault rate
d) to allocate multiple pages to processes
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10. A FIFO replacement algorithm associates with each page the _______
a) time it was brought into memory
b) size of the page in memory
c) page after and before it
d) all of the mentioned
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11. What is the Optimal page – replacement algorithm?
a) Replace the page that has not been used for a long time
b) Replace the page that has been used for a long time
c) Replace the page that will not be used for a long time
d) None of the mentioned
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12. Optimal page – replacement algorithm is difficult to implement, because ____________
a) it requires a lot of information
b) it requires future knowledge of the reference string
c) it is too complex
d) it is extremely expensive
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13. LRU page – replacement algorithm associates with each page the ______
a) time it was brought into memory
b) the time of that page’s last use
c) page after and before it
d) all of the mentioned
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14. For 3 page frames, the following is the reference string:
7 0 1 2 0 3 0 4 2 3 0 3 2 1 2 0 1 7 0 1
How many page faults does the LRU page replacement algorithm produce?
a) 10
b) 15
c) 11
d) 12
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15. What are the two methods of the LRU page replacement policy that can be implemented in hardware?
a) Counters
b) RAM & Registers
c) Stack & Counters
d) Registers
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More MCQs on Page Replacement Algorithms:

• Page Replacement Algorithms MCQ (Set 2)

Sanfoundry Global Education & Learning Series – Operating System.