Questions
Syllabus
Qns. By Syllabus

Semester

Subject

Year

Bachelors Level/Second Year/Fourth Semester/Science csit/fourth semester/operating systems/syllabus wise questions

B.Sc Computer Science and Information Technology

Institute of Science and Technology, TU

Operating Systems (CSC264)

Year Asked: 2080, syllabus wise question

Device Management
1.
What are the advantages of using interrupt? Describe. [5]
File Management
1.
Suppose a disk has 201 cylinders, numbered from 0 to 200. At same time the disk arm is at cylinder 10, and there is a queue of disk access requests for cylinders 30, 85, 90, 100, 105, 110, 135, and 145. Find the total seek time for the disk scheduling algorithm FCFS and SSTF. Assume the head is moving inward. [5]
2.
Differentiate between contiguous and linked list file allocation technique. [5]
Memory Management
1.
Explain different memory allocation strategies. [5]
2.
Differentiate between paging and segmentation. [5]
3.
What does Belady's anomaly mean? What are the benefits of multiprogramming over uniprogramming? [5]
4.
When does a page fault occur? Give a structure of a page table. [5]
Process Deadlocks
1.
Can deadlock occur in case of preemptive resources? List the conditions for deadlock. Define allocation graph with example. [10]
Process Management
1.
When does the request switch from user mode to kernel mode? Give answer with an example. Find the average waiting time and turnaround time for the process scheduling algorithms FCFS, Priority and RR (Quantum=2) in the following given dataset.

$\begin{array}{|c|c|c|c|c|} \hline \text{Process} & \text{Arrival Time} & \text{Burst Time} & \text{Priority} \\ \hline P0 & 0 & 5 & 1 \text{ (Lowest)} \\ P1 & 1 & 3 & 4 \text{ (Highest)} \\ P2 & 2 & 8 & 2 \\ P3 & 3 & 6 & 3 \\ \hline \end{array}$
[10]
2.
How do you recognize critical section? Why do we need to synchronise it? Consider the request for the page references 7,0,1,2,0,3,0,4,2,3,0,3,2. Find the number of page fault for FIFO and LRU with 4 page frames. [10]
3.
How can we achieve mutual exclusion? Describe. [5]
4.
What makes thread different with process? Draw the transition diagram between states of a process. [5]