Operating System Mock Test #1: CPU Scheduling, Synchronization & Deadlocks

Question 1 of 5 Correct: +2 | Negative: -0.5

Consider a system having 5 processes where each process requires a maximum of 4 instances of resource type R. What is the minimum number of instances of R required so that deadlock NEVER occurs?

A 15 B 16 C 20 D 19

Clear Selection

Question 2 of 5 Correct: +2 | Negative: -0.5

Which of the following CPU scheduling algorithms is provably optimal in terms of providing the minimum average waiting time for a given set of processes?

A First Come First Serve (FCFS) B Round Robin (RR) C Shortest Remaining Time First (SRTF / Preemptive SJF) D Multilevel Queue Scheduling

Clear Selection

Question 3 of 5 Correct: +2 | Negative: -0.5

A counting semaphore is initialized to 12. Then 10 P (wait) operations and 6 V (signal) operations are completed on this semaphore. What is the resulting value of the semaphore?

A 8 B 16 C 6 D 4

Clear Selection

Question 4 of 5 Correct: +2 | Negative: -0.5

Which phenomenon occurs in Dynamic Partitioning / Segmentation when free memory is broken into many small non-contiguous blocks and cannot satisfy a request despite sufficient total free memory?

A Internal Fragmentation B External Fragmentation C Thrashing D Belady's Anomaly

Clear Selection

Question 5 of 5 Correct: +2 | Negative: -0.5

Belady's Anomaly (increasing the number of page frames results in an increase in the number of page faults) can occur in which page replacement algorithm?

A LRU (Least Recently Used) B Optimal Page Replacement C FIFO (First-In First-Out) D Both LRU and Optimal

Clear Selection