Advanced Operating Systems Multiple
Choice Questions (MCQs) with Answers and
Explanations for Degree, Master's and
Professional Certification Exams
1. A multiprogramming operating system aims to maximize CPU utilization. Which
scheduling strategy generally minimizes average waiting time when process burst times
are known?
A. First-Come, First-Served (FCFS)
B. Round Robin
C. Priority Scheduling
D. Shortest Job First (SJF)
Explanation: SJF minimizes average waiting time by executing processes with the shortest CPU
bursts first, reducing the overall time processes spend waiting in the ready queue.
2. Which page replacement algorithm may exhibit Belady's anomaly?
A. Least Recently Used (LRU)
B. Optimal Replacement
C. Clock Algorithm
D. First-In, First-Out (FIFO)
Explanation: FIFO can suffer from Belady's anomaly, where increasing the number of page
frames unexpectedly increases the number of page faults.
3. A system employs semaphores to coordinate access to shared resources. Which
semaphore operation potentially blocks a process when the resource is unavailable?
A. Signal
B. Release
C. Notify
, D. Wait
Explanation: The wait operation decrements the semaphore and blocks the process if the
semaphore value becomes negative, ensuring mutual exclusion.
4. In virtual memory systems, what is the primary purpose of a Translation Lookaside
Buffer (TLB)?
A. Store page replacement statistics
B. Manage disk scheduling
C. Buffer file system requests
D. Cache recently used page table entries
Explanation: The TLB accelerates address translation by caching frequently accessed page
table entries, reducing memory access latency.
5. Which condition is not one of the four necessary conditions for deadlock?
A. Mutual exclusion
B. Hold and wait
C. Circular wait
D. Preemptive scheduling
Explanation: The Coffman conditions for deadlock are mutual exclusion, hold and wait, no
preemption, and circular wait. Preemptive scheduling is unrelated.
6. In a preemptive Round Robin scheduler, reducing the time quantum excessively is likely
to result in:
A. Reduced context switching overhead
B. Improved throughput
C. Lower response time with no disadvantages
D. Excessive context switching overhead
Explanation: Very small time slices cause frequent context switches, increasing overhead and
reducing CPU efficiency.
Choice Questions (MCQs) with Answers and
Explanations for Degree, Master's and
Professional Certification Exams
1. A multiprogramming operating system aims to maximize CPU utilization. Which
scheduling strategy generally minimizes average waiting time when process burst times
are known?
A. First-Come, First-Served (FCFS)
B. Round Robin
C. Priority Scheduling
D. Shortest Job First (SJF)
Explanation: SJF minimizes average waiting time by executing processes with the shortest CPU
bursts first, reducing the overall time processes spend waiting in the ready queue.
2. Which page replacement algorithm may exhibit Belady's anomaly?
A. Least Recently Used (LRU)
B. Optimal Replacement
C. Clock Algorithm
D. First-In, First-Out (FIFO)
Explanation: FIFO can suffer from Belady's anomaly, where increasing the number of page
frames unexpectedly increases the number of page faults.
3. A system employs semaphores to coordinate access to shared resources. Which
semaphore operation potentially blocks a process when the resource is unavailable?
A. Signal
B. Release
C. Notify
, D. Wait
Explanation: The wait operation decrements the semaphore and blocks the process if the
semaphore value becomes negative, ensuring mutual exclusion.
4. In virtual memory systems, what is the primary purpose of a Translation Lookaside
Buffer (TLB)?
A. Store page replacement statistics
B. Manage disk scheduling
C. Buffer file system requests
D. Cache recently used page table entries
Explanation: The TLB accelerates address translation by caching frequently accessed page
table entries, reducing memory access latency.
5. Which condition is not one of the four necessary conditions for deadlock?
A. Mutual exclusion
B. Hold and wait
C. Circular wait
D. Preemptive scheduling
Explanation: The Coffman conditions for deadlock are mutual exclusion, hold and wait, no
preemption, and circular wait. Preemptive scheduling is unrelated.
6. In a preemptive Round Robin scheduler, reducing the time quantum excessively is likely
to result in:
A. Reduced context switching overhead
B. Improved throughput
C. Lower response time with no disadvantages
D. Excessive context switching overhead
Explanation: Very small time slices cause frequent context switches, increasing overhead and
reducing CPU efficiency.
