B.C.A. (Semester IV) (CGPA) Examination Nov/Dec-2018
OPERATING SYSTEM
Time: 2½ Hours Max. Marks: 70
Instructions: Q.1 and Q.7 are compulsory.
Attempt any two questions from Q. 2 to Q. 4.
Solve any one questions from Q.5 and Q.6.
Figures to the right indicate full marks.
Q.1 Choose the correct alternative. 09
In a segmentation scheme the logical memory will be divided into
Pages Frames
Blocks Segments
has lowest page fault rate.
FIFO LRU
Optimal page replacement None of the above
allocation scheme suffers from external fragmentation.
Segmentation Pure demand paging
Swapping Paging
directories to share subdirectories and files.
Acyclic graph Single level directories
Two level directories Tree structure directories
The number of processes completed per unit time is known as
Output Throughput
Efficiency Capacity
Resources are allocated to the process on non-sharable basis is

Mutual exclusion Hold and wait
No pre-emption Circular wait
The information about all files is kept in
Swap space Operating system
Separate directory structure None
Which of the following memory management scheme loads all pages of
a program from disk into main memory?
Paging Demand paging
Segmentation Demand segmentation
File type can be represented by
File name File extension
File identifier None of the above.
Q.1 State True or False:- 05
Direct access files are used for immediate access to large amounts of
information.
Wait for graph is used for deadlock avoidance.
The Process Control Block is data structure.
A page fault occurs when the page is in the memory.
Linked allocation method solves external fragmentation.
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SLR-CH-3
Q.2 Answer any two the following. 14
What is deadlock? Explain 4 necessary conditions of deadlock.
Describe different types of file access methods.
What is swapping? Why does one need to swap areas of memory?
Q.3 Answer any two of the following. 14
Explain round robin scheduling algorithm with example.
What is an O.S.? Explain the types of operating system.
Explain Paging in detail.
Q.4 Answer any two of the following. 14
Calculate the total number of page fault using optimal page replacement and
LRU Page replacement algorithm on following reference string having
maximum 03 frames- 1
Explain Inter process communication in detail.
Explain different system components of operating system in detail.
Q.5 "What are the requirements to solve the critical section problem? 07
Explain any two methods of allocating disk space. 07
Q.6 State and explain various directory structures. 07
Consider the following snap shot of a system having 5 processes
and 4 resource types D
Process Allocation Max Available
A B C D A B C D A B C D
P0 0 0 1 2 0 0 1 2 1 5 2 0
P1 1 0 0 0 1 7 5 0
P2 1 3 5 4 2 3 5 6
P3 0 6 3 2 0 6 5 2
P4 0 0 1 4 0 6 5 6
Answer the following questions using the banker's algorithm:
What is the content of the matrix Need?
Is the system in a safe state?
If a request from process P1 arrives for can the request be
granted immediately?
07
Q.7 Write short notes on the following (Any Two) 14
Process Control Block
Semaphore
Priority Scheduling