Question Paper: Operating System : Question Paper Jun 2014 - Computer Engineering (Semester 4) | Gujarat Technological University (GTU)
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## Operating System - Jun 2014

### Computer Engineering (Semester 4)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.
1 (a) Explain the objectives and functions of operating systems.(7 marks) 1 (b) Define a process. Explain the process state transition with a neat diagram.(7 marks) 2 (a) What is thread and what are the differences between user-level threads and kernel supported threads? Under what circumstances is one type 'better' than the other?(7 marks) 2 (b) Explain the Problem of Critical Section (CSP) through Producer Consumer Problem. Explain any one Solution in detail.(7 marks) 2 (c) Write short note: 1) Semaphores 2) Monitors(7 marks) 3 (a) Find average waiting time for Shortest job first scheduling, and Round robin scheduling algorithm.

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 Process CPU burst time P1 6 P2 8 P3 5 P4 2

CPU burst time is given in millisecond and time quantum is 4.(7 marks) 3 (b) What do you mean by Deadlock Avoidance? Explain the use of Banker's Algorithm for Deadlock Avoidance with illustration.(7 marks) 3 (c) Consider the following set of processes with the length of CPU burst time given in the milliseconds.
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 Process Arrival Time Burst Time Priority P1 0 8 3 P2 1 1 1 P3 2 3 2 P4 3 2 3 P5 4 6 4

Calculate average turnaround time and average waiting time for First-come first served scheduling, Shortest job first scheduling and Priority scheduling algorithm.
(7 marks)
3 (d) What is Deadlock? List the conditions that lead to deadlock. How Deadlock can be prevented?(7 marks) 4 (a) Explain the following allocation algorithms: 1) First-fit 2) Best-fit 3) Worst-fit(7 marks) 4 (b) Write short note: 1) Direct memory access (DMA) 2) Device controllers(7 marks) 4 (c) What is fragmentation? What is the need of fragmentation? Explain the difference between internal and external fragmentation.(7 marks) 4 (d) Write short note: RAID levels(7 marks) 5 (a) Explain in details about file attributes and file operations.(7 marks) 5 (b) What is 'inode'? Explain File and Directory Management of Unix Operating System.(7 marks) 5 (c) Describe various file organization Techniques.(7 marks) 5 (d) Define distributed system. Explain the characteristics of distributed system.(7 marks)