Gujarat University
MCA Semester III
Operating Systems
Date: 8th January, 2000 Marks: 50
Instructions:
1. Answers to the two sections must be written in the separate answer books.
2. Figures to the right indicate full marks.
3. Assume the necessary data, if necessary.
Section I
Q-1 a) Define the following terms: [5]
1. Multitasking
2. Mutual exclusion
3. Microkernel
4. Response time
5. Multiprocessing and distributed processing
b) Answer the following in brief: [4]
i) Write the difference between context switching and process switching.
ii) What is thread? Give advantages of threading.
iii) What actions are taken while creating a new process and terminating a process?
iv) Give the advantages of using monitor.
Q-2 a) What is process? Describe the elements of PCB in detail. [4]
b) Describe Readers-writers problem. Implement it using semaphore. [4]
OR
Q-2 a) What is semaphore? Give and explain the algorithm of producer/ consumer problem with bounded buffer
using general semaphore. [4]
b) Discuss the five state process model. Explain also various queues developed for different states. What do
you mean by spanned state? [4]
Q-3 a) Describe the necessary conditions for deadlock occurrence. Discuss the deadlock avoidance using
Banker’s algorithm. Also discuss data structures for implementing this algorithm. [4]
b) Consider the following set of processes: [4]
Process P1 P2 P3 P4 P5
Arrival time 0 2 4 6 8
(milliseconds)
CPU Burst time 10 19 3 7 12
Calculate turnaround time of each process and average waiting time of FCFS, SPN, RR (Quantum = 3)
scheduling disciplines.
OR
Q-3 a) Explain the windows NT architecture with illustration. [4]
b) Write short notes on following: [4]
i) Remote Procedure Call
ii) Message passing system
Section II
Q-4 a) Define the following terms: [5]
i) Thrashing
ii) Trojan horse attack
iii) Virtual memory
iv) Disk cache
v) Inodes in UNIX
b) Answer the following: [4]
i) Explain in brief various types of fragmentation occurring in memory.
ii) Compare LRU and FIFO algorithm for page replacement.
iii) What actions are taken when page fault occurs?
iv) Give the names of various disk. Scheduling algorithms. Explain any one of them.
Q-5 a) Explain the overall performance of static partitioned memory allocation with respect to principles of
allocation relocation, protection sharing. [4]
b) What is file system? Explain file system software architecture. Also comment on UNIX file system. [4]
OR
Q-5 a) Discuss contiguous, chained and indexed file allocation methods. What do you mean by Disk inter
leaving? [4]
b) Discuss the use of TLB in paging and segmentation technique. How physical address is generated in it? [4]
Q-6 A) Explain the combined paging and segmentation technique. How physical address is generated in it?
[4]
b) Discuss I/O Buffering schemes. [4]
OR
Q-6 a) Describe the nature of threats faced by different computer system assets. [4]
b) Write short notes on any two of the following: [4]
i) Device driver
ii) Password selection strategies
iii) Memory management in Windows NT
