Tuesday, December 08, 2015
Roll No……………
Total No.of Questions :13]
Paper ID [A0303]
(Please fill the
Paper ID in OMR sheet)
B.Sc.(
IT-103/201/302) DCA (S05) (New /Old ) (Sem. -1st )
OPERATING SYSTEM
Time :03 Hours Max
Marks : 75
Instruction
to Candidates :
1) Section
–A is Compulsory .
2) Attempt any Nine question from Section –B .
Section
–A
Q1)
a) Why must a computer start in kernel
mode when power is first turned on ?
b) What is the principal advantage
of multiprogramming ?
c)
On a system using multilevel feedback queues, what is the advantage of using a different time quantum in each
queue ?
d) What are the differences between a
process and thread ?
e) Define race condition and how it is
avoided .
f) Is it possible to occure a
feedlock in a single process ?
g) Differentiate physical and logical
address space.
(h) What type of fragmentation is
there in paging and why?
(i) The second chance algorithm
rejects pages that have their reference bit set
to 1. What happens if all pages have their reference bit set to 1?
(j)What is pre-paging?
(k) Describe interrupt vector.
(l) On a system using index access,
what should happen if no record matches the
index value or a read request?
(m) What is the difference between
random access and sequential access?
(n) What are the different types of
commands supported by shell?
(o) What is dispatcher and give its
functions?
Section
–B
Q2. Explain the layered structure of MS-DOS.
Q3. Explain
the use of the process control block (PCB). Discuss the contents of PCB.
Q4.
Consider the following set of
processes, with the length of CPU-burst time given
in milliseconds:
|
Process
|
Burst Time
|
Priority
|
|
P1
|
10
|
3
|
|
P2
|
1
|
1
|
|
P3
|
2
|
3
|
|
P4
|
1
|
4
|
|
P5
|
5
|
2
|
The processes are assumed to have
arrived in the order P1, P2, P3, P4, P5 at all
time 0
(a) What is the turnaround time of
each process for using FCFS, SJF, a non- preemptive
priority (a smaller priority number implies a higher priority) and RR (quantum=1) scheduling.
(b) What is the waiting time of each
process for each of the scheduling algorithm in part a.
Q5.
Explain readers and writers problem in
process synchronization.
Q6.
Consider the following snapshot of a
system:
|
|
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.
(a) What is the contents of matrix
need?
(b) Is the system in a safe state?
(c) If a request from P1 arrives for
(0,4,2,0) can the request be granted immediately?
Q7.
Given memory partitions of 100K, 500K,
200K, 300K and 600K (in order) how
would each of the first fit, best fit and worst fit algorithms place processes of 212K, 417K, 112K and 426K (in
order)? Which algorithm makes the
most efficient use of memory?
Q8.
Explain the paging memory management
scheme in detail.
Q9. When
do page faults occur? Describe the action taken by the operating system when a page fault occurs.
Q10.
Consider the following page reference
string:
1,2,3,4,1,5,6,2,1,2,3,7,6,3,2,1,2,3,6.
How many page faults would occur for
the following replacement algorithms,
assuming three frames? Remember that all frames are initially empty,
(a) LRU replacement
(b) FIFO replacement
(c) Optimal replacement
Q11.
What is directory structure? Explain
single level, two level and hierarchical structure
directory with their advantages and disadvantages.
Q12.
Explain I/O hardware with a typical pc
bus structure.
Q13.
Explain the properties of batch,
multi-programmed, time shared operating systems.
0 comments:
Post a Comment
North India Campus