Operating System MCQs with Answers
Practice important Operating System MCQs with answers and explanations.
Chapter: 38
Q1041:
What is the key difference between vfork() and fork()?
A. vfork() suspends the parent process while creating the child
B. vfork() creates a duplicate of the parent’s address space
C. fork() requires less memory than vfork()
Correct Answer:
A
Chapter: 39
Q1042:
What happens when a page fault occurs in a user process?
A. The process is terminated
B. The page is loaded from the disk
C. The page is removed from memory
D. The page is swapped out
Correct Answer:
B
Chapter: 39
Q1043:
The operating system’s page-fault service routine includes which step when no free frame is available?
A. Terminate the process
B. Swap out a process
C. Use a page replacement algorithm
D. Allocate more memory
Correct Answer:
C
Chapter: 39
Q1044:
When a page’s modify bit is set, it indicates that _________.
A. The page is being accessed
B. The page has been modified
C. The page is not in memory
D. The page is being replaced
Correct Answer:
B
Chapter: 39
Q1045:
FIFO stands for _________.
A. First In, Fast Out
B. First In, First Out
C. Fast In, Fast Out
D. None of the above
Correct Answer:
B
Chapter: 39
Q1046:
What is the main disadvantage of the FIFO page replacement algorithm?
A. High page fault rate
B. Belady’s anomaly
C. Complex to implement
D. Low page fault rate
Correct Answer:
B
Chapter: 39
Q1047:
The optimal page replacement algorithm replaces the page that _________.
A. Is least recently used
B. Will not be used for the longest period of time
C. Has not been accessed in the past
D. Has been modified
Correct Answer:
B
Chapter: 39
Q1048:
The LRU page replacement algorithm approximates the optimal algorithm by replacing the page that _________.
A. Was used the least recently
B. Is least recently used
C. Has been in memory for the longest time
D. Is the oldest
Correct Answer:
A
Chapter: 39
Q1049:
The FIFO algorithm associates with each page _________.
A. A reference string
B. A time when it was last accessed
C. A time when it was brought into memory
D. The number of page faults
Correct Answer:
C
Chapter: 39
Q1050:
Which of the following page replacement algorithms is most difficult to implement due to future knowledge requirements?
A. FIFO
B. Optimal
C. LRU
D. None of the above
Correct Answer:
B
Chapter: 39
Q1051:
The number of page faults decreases when _________.
A. The number of free frames increases
B. The page table is modified
C. The process is swapped out
D. A page is replaced
Correct Answer:
A
Chapter: 39
Q1052:
LRU page replacement may require _________.
A. Substantial hardware assistance
B. Minimal memory
C. No extra resources
D. A larger time frame
Correct Answer:
A
Chapter: 39
Q1053:
In the stack-based implementation of the LRU algorithm, the _________ is always the most recently used page.
A. Bottom of the stack
B. Middle of the stack
C. Top of the stack
D. First page
Correct Answer:
C
Chapter: 39
Q1054:
In the counter-based implementation of LRU, the page that is replaced is the one with _________.
A. The smallest time-of-use value
B. The most recent time-of-use value
C. The largest time-of-use value
D. The most modified time-of-use value
Correct Answer:
A
Chapter: 39
Q1055:
The page replacement algorithm that suffers from Belady’s anomaly is _________.
A. FIFO
B. Optimal
C. LRU
D. None of the above
Correct Answer:
A
Chapter: 39
Q1056:
A page fault occurs when _________.
A. The page is not found in the frame
B. The page is being swapped out
C. A new frame is needed
D. The modify bit is not set
Correct Answer:
A
Chapter: 39
Q1057:
Which page replacement algorithm guarantees the lowest possible page-fault rate for a fixed number of frames?
A. FIFO
B. Optimal
C. LRU
D. None of the above
Correct Answer:
B
Chapter: 39
Q1058:
The FIFO algorithm uses a _________ to hold all pages in memory.
A. Stack
B. Queue
C. Table
D. List
Correct Answer:
B
Chapter: 39
Q1059:
In the LRU page replacement algorithm, the page that has not been used for the _________ period of time is replaced.
A. Longest
B. Shortest
C. Most recent
D. Last
Correct Answer:
A
Chapter: 39
Q1060:
In the FIFO page replacement algorithm, when a page is brought into memory, it is inserted at _________.
A. The head of the queue
B. The tail of the queue
C. The front of the queue
D. The middle of the queue
Correct Answer:
B