Centre for Development of Advanced Computing(C-DAC) 2005 M.C.A 201 Operating System - Question Paper

END-TERM exam
Third Semester [MCA] - DECEMBER 2005
Paper Code: MCA 201 Subject: Operating System
Time: three Hours Maximum Marks: 70

Q. 1.
(a) elaborate the difference ranging from trap and interrupt?
(b) What is the purpose of base and limit registers?
(c) What is the purpose of command interpreter?
(d) Difference ranging from system calls and system programs.
(e) What is the difference ranging from user level and kernel level threads?
(f) describe the difference ranging from pre-emptive and non pre-emptive
scheduling?
(g) Is it possible to have a deadlock involving only 1 single process?
Explain.
(h) What do you mean by memory fragmentation?
8 x 2.5 = 20

UNIT - I

Q. 2.
(a) What is paging? How it differs from segmentation? discuss a system
which uses a combined scheme of segmentation with paging. 6
(b) Consider a paging system with the page table stored in memory. If a
memory reference takes 200 nano secs and 80 percent of all page
table references are obtained in the associative registers, what is the
effective memory reference time? (Assume associative register
references time as zero). 4

Q. 3.
(a) Consider the subsequent page reference string:- 6
1, 5, 2, 3, 2, 1, 4, 2, 3, 5, 1, 2, 5, 4, 3, 2, 4, 1, 2
How many page faults will occur assuming 3 frames for
(i) LRV
(ii) FIFO and
(iii)Optimal Replacement
(b) define the steps how a page fault is handled by the operating
system. 4

UNIT - II

Q. 4.
(a) elaborate the necessary conditions for a deadlock to occur? discuss. 5
(b) discuss Banker’s algorithm for deadlock avoidance. 5

Q. 5.
(a) elaborate semaphores? How these are implemented? 4
(b) discuss with examples the subsequent scheduling algorithm. 6
(i) FCFS
(ii) SJF
(iii)Round Robin

UNIT - III

Q. 6. Suppose a disk queue with requests for I/O to blocks on cylinders:-
10
100, 175, 50, 120, 120, 20, 150, 75, 200
If the disk head is currently at 60, obtain out the total disk head movement for the
subsequent algorithm:-
(a) FCFS
(b) SSTP
(c) SCAN
(d) LOOK
(e) C-SCAN

Q. 7.
(a) How swap space is managed by the Operating system? discuss. 5
(b) elaborate interrupt? How interrupt are handled by the operating
system? 5

UNIT - IV

Q. 8. discuss the contiguous, linked and indexed file allocation techniques with
suitable example. What technique is used in Unix Operating System? 10

Q. 9.
(a) elaborate the various file access methods? 5
(b) discuss the various directory structure? 5

Earning:   Approval pending.