NPTEL Operating System Fundamentals Week 11 Assignment Answers 2024
1. Assuming that the memory frames are initially empty, for the page reference string: 5, 0, 2, 1, 0, 3, 0, 2, 4, 3, 0, 3, 2, 1, 3. Compute the number of page faults in the FIFO page replacement policy with three memory frames.
(A) 11
(B) 12
(C) 13
(D) 14
(E) 15
Answer :- For Answers Click Here
2. Calculate the page fault rate for the following reference string: 5, 0, 2, 1, 0, 3, 0, 2, 4, 3, 0, 3, 2, 1, 3, using the optimal page-replacement algorithm with three frames.
(A) 40%
(B) 46.66%
(C) 60%
(D) 66.66%
(E) 53.33%
Answer :- For Answers Click Here
3. Consider a computer system executing a process of size 12KB in the main memory with the following page reference strings: 5, 0, 2, 1, 0, 3, 0, 2, 4, 3, 0, 3, 2, 1, 3. The size of each page is 4KB. Compute the number of page fault rate for the Least Recently Used (LRU) page replacement algorithm for three frames.
(A) 46.66%
(B) 66.66%
(C) 53.33%
(D) 73.33%
(E) 63.33%
Answer :-
4. Consider a computer system with 12KB of main memory, and each frame/page size is 4KB. Assume that a process of size 20KB will be executed in the main memory with the following page reference string 0, 1, 2, 3, 4, 1, 2, 0, 1, 2, 1, 4, 1. Compute the page fault rate for the second-chance (clock) page replacement algorithm.
(A) 60%
(B) 50%
(C) 40%
(D) 70%
(E) 55%
Answer :-
5. Assume that a computer system executes three processes P1, P2, and P3. The P1, P2, and P3 processes are allocated 32, 189, and 65 pages. The size of each frame is 4KB. The size of the physical frame is 460KB. How many frames will be allocated to each process following the “Proportional allocation” strategy?
(A) 13, 76, and 26
(B) 13, 75, and 27
(C) 12, 76, and 27
(D) 32, 189, and 65
(E) 14, 74, and 27
Answer :-
6. The optimal page replacement algorithm is not practical because
(A) memory access time is unknown
(B) page size is unknown
(C) TLB search time is unknown
(D) the size of the working set is unknown
(E) future memory references are unknown
Answer :- For Answers Click Here
7. Choose the correct statement concerning the Enhanced Second-Chance page replacement algorithm.
(A) It is a modification of the FIFO page replacement algorithm.
(B) It uses reference and modification (dirty) bits to decide which page to replace.
(C) Pages with reference and modification bits set to 1 are replaced first.
(D) It only uses the reference bit to determine if a page gets a second chance.
(E) It does not consider the modification bit during page replacement.
Answer :-
8. Assume that a computer system executes a process in the main memory with the following page reference strings: 3, 3, 4, 2, 3, 5, 3, 5, 1, 4. The initial working set window size (∆) is 4. The initial working set window at time t = 0 contains the pages {5,4,1}, where page 5 was referenced at time t = -2, page 4 at time t = −1, and page 1 at time t = 0. What is the total number of page faults and the average number of page frames used by computing the working set at each reference?
(A) 5 and 3.5
(B) 5 and 4.5
(C) 6 and 3.2
(D) 5 and 3.2
(E) 4 and 4.2
Answer :-
9. The LRU algorithm can be implemented using
(A) Additional-Reference-Bits
(B) Counter
(C) Second-Chance Algorithm
(D) Stack
(E) All of the above
Answer :-
10. A global page replacement algorithm
(A) allocates a fixed number of frames to each process.
(B) replace a page within the frames allocated to the specific process.
(C) is more flexible but can cause one process to take a disproportionate amount of memory.
(D) ensures that each process gets an equal share of memory frames.
(E) ensures better locality of reference compared to local page replacement algorithms.
Answer :- For Answers Click Here
