M.C.A. (Semester II) (CBCS) Examination Nov/Dec-2018
Science
OPERATING SYSTEM
Time: 2½ Hours Max. Marks: 70
Instructions: Question No. 1 and 2 are compulsory.
Attempt any 3 questions from Q. no. 3 to Q. no. 7
Figures to the right indicate full marks.
Q.1 Choose the correct alternatives. 10
Software may trigger by executing a special operation
called a System call.
Interrupt Action
Ready state Application
In the absence of expensive battery and generator backup systems, data
must be written to for safekeeping.
Volatile storage Non volatile storage
Both and None of these
Multiprogramming CPU utilization by organizing jobs (code
and data) so that the CPU always has one to execute.
Decreases Decline
Reduce Increases
is a passive entity, such as the contents of a file stored on
disk.
Process Semaphore
Program Paging
A usually links buildings, cities or countries
Local- area network Wide- area network
Metropolitan- area network None of these
algorithm is simply a priority algorithm where the priority
is the inverse of the (predicted) next CPU burst
Optimal page replacement First Come First Serve
Disk Scheduling Shortest Job First
A state is safe if the system can allocate resources to each process up
to its maximum) in some order and still avoid a
Scheduling Multiprogramming
Deadlock Synchronization
Best fit strategy allocates the hole that is big enough. We
must search the entire list, unless the list is ordered by size.
Z
largest smallest
first medium
When a page must be replaced, least-recently-used algorithm
chooses the page that has not been used for the period of time.
Shortest Longest
Just now Recent
Page 2 of 2
SLR-SN-9
10) scheduling is a variant of SCAN designed to
provide a more uniform wait time.
Centered SCAN Circular SCAN
Continuous SCAN Controlled SCAN
Sate whether true or false 04
Each process is represented in the operating system by a memory
control block.
When a class is running a word-processor program, a multiple thread of
instructions is being executed.
The security system prevents unauthorized access, malicious destruction
or alteration of data, and accidental introduction of inconsistency.
The processes that are residing in main memory and are ready and
waiting to execute are kept on a list called the ready queue.
Q.2 Write a short note 08
Fragmentation
Process state
Answer the following 06
What do you mean by preemptive algorithm?
What do you mean by race condition?
Q.3 Answer the following 14
What do you mean by Deadlock? Discuss deadlock characterization in detail
What do you mean by Operating System? Discuss in detail vital role of
Operating System as being resource allocator.
Q.4 Answer the following 14
Define the term process Synchronization. Discuss in detail Readers-Writers
problem.
State and describe the principle of SCAN disk scheduling algorithm. Perform
SCAN with a disk queue requests are as follows
Queue 118, 63, 112, 13, 65, 38, 88, 175, 53, 122, 28
Head starts at 50
Q.5 Answer the following. 14
Define the term Security and Protection? Enlist and discuss in detail forms of
accidental and malicious security violations.
Define the term Demand paging? Discuss the steps to be taken to handle
the page fault
Q.6 Answer the following. 14
What do you mean Cooperative Process? Discuss in detail how interprocess
communication will be made between processes?
Calculate the total number of page fault using Most Recently Used
page replacement on following reference string having maximum 03 frames-

Q.7 Answer the following. 14
Demonstrate working of Shortest Job First algorithm using following data-
P_NAME ABC XYZ PQR LMN STU
P_BURST TIME 19 13 15 11 18
What do you mean by File? Discuss in detail concept of file allocation
method.