BCS303
Model Question Paper-I with effect from 2023-24 (CBCS Scheme)
USN
Third Semester B.E. Degree Examination
Operating Systems
TIME: 03 Hours Max. Marks: 100
Note: 01. Answer any FIVE full questions, choosing at least ONE question from each MODULE.
*Bloom’s
Module -1 Taxonomy Marks
Level
Q.01 a Distinguish between the following terms.
(i) Multiprogramming and Multitasking L2 6
(ii) Multiprocessor System and Clustered System
b Define operating Systems. Explain the dual-mode operating system with a neat
L2 7
diagram.
c With a neat diagram, explain the concept of the virtual machine. L2 7
OR
Q.02 a Explain the layered approach of operating system structure with a supporting
L2 6
diagram.
b What are system calls? Briefly point out its types with illustrations. L2 6
c Explain the services of the operating system that are helpful for the user and the
L2 8
system.
Module-2
Q. 03 a With a neat diagram, explain the states of a process with a transition diagram and
L2 6
process control block.
b What is inter-process communication? Discuss message passing and the shared
L2 6
memory concept of IPC.
c Calculate average waiting and turnaround times by drawing the Gantt
chart using FCFS and RR (q=2ms).
Processes Arrival Time Burst Time
P1 0 9 L3 8
P2 1 4
P3 2 9
P4 3 5
OR
Q.04 a Discuss in detail the multithreading model, its advantages and
L2 7
disadvantages with suitable illustration.
b Explain five different scheduling criteria used in the computing scheduling
L2 5
mechanism.
c Calculate the average waiting time and the average turnaround time by
drawing the Gantt chart using SRTF and the Priority scheduling algorithm.
Processes Arrival Time Burst Time Priority
P1 0 8 3 8
L3
P2 1 4 2
P3 2 9 1
P4 3 5 4
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BCS303
Module-3
Q. 05 a Define deadlock. What are the necessary conditions for deadlock to occur? L2 5
b Illustrate Peterson’s solution for the critical section problem. L2 6
c Consider the following snapshot of the 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
L3 9
P4 0 0 1 4 0 6 5 6
Answer the following questions using Banker’s algorithm:
a. What is the content of the need matrix?
b. Is the system in a safe state? If yes, mention the safe sequence.
If a request from process P1 arrives for (0,4,2,0) can the request be granted
immediately?
OR
Q. 06 a Explain different methods to recover from deadlocks. L2 6
b What is a resource allocation graph? Consider an example to explain how it is
L2 6
very useful in describing a deadly embrace.
c What is a semaphore? State a Dining Philosopher problem gives a solution using
L2 8
semaphore.
Module-4
Q. 07 a What is TLB? Explain TLB in detail with a paging system with a neat diagram. L2 6
b With the help of a neat diagram, explain the various steps of address binding. L2 6
c Consider the page reference string: 1,0,7,1,0,2,1,2,3,0,3,2,4,0,3,6,2,1 for a
memory with three frames. Determine the number of page faults using the FIFO, L3 8
Optimal, and LRU replacement algorithms. Which algorithm is most efficient?
OR
Q. 08 a What is demand paging? Explain the steps in handling page faults using the
L2 6
appropriate diagram.
b What is segmentation? Explain the basic method of segmentation with an
L2 6
example.
c Discuss the structure of the page table with a suitable diagram. L2 8
Module-5
Q. 09 a What is a file? What are its attributes? Explain file operations. L2 6
b Explain in detail about various file operations in a file system. L2 6
c Discuss various directory structures with neat diagrams. L2 8
OR
Q. 10 a Explain contiguous and linked disk space allocation methods. L2 6
b Explain the access matrix method of system protection with the domain as objects
L2 6
and its implementation.
c Given the following sequences 95,180,34,119,11,123,62,64 with the track 50 and
ending track 199. What is the total disk travelled by the disk arm using FCFS, L3 8
SSTF, LOOK and CLOOK algorithm
*Bloom’s Taxonomy Level: Indicate as L1, L2, L3, L4, etc. It is also desirable to indicate the COs and POs to be
attained by every bit of question.
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