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OPERATING SYSTEM (2A)
YEAR 2013
1. Define the following terms:(10)
(a) Demand paging
(b) Swapping
(c) DMA
(d) Thrashing
2. Differentiate between:(10)
(a) Network Operating System and Distributed OS.
(b) Spooling and Buffering.
3. Explain contiguous allocation, linked allocation and indexed allocation of file with diagram and example.(10)
4. What is multiprogramming? Explain multi-programming with dynamic partition with example and diagram.
How it is better then multi-programming with fixed partition?(10)
5. Consider the following set of processes which arrive in the ready queue of the same time.(10)
Process CPU time
P1 10
P2 5
P3 2
P4 8
P5 5
Consider the following scheduling algorithms
FCFS, SJF, Round Robin (quantum=1). What is turnaround time and waiting time of each process for each of
the above scheduling algorithms?
6. (a) What is virtual memory. Explain it with its advantages and disadvantages.(10)
(b) Discuss with example about the FIFO page replacement algorithm.
7. Describe the following commands:(10)
(a) Chmod
(b) Grep
(c) Sort
(d) Cat
8. Describe the design principle of WINDOWS-NT.(10)
YEAR 2012
1. Define the essential properties of the following types of operating system :
(a) Multi-programming batch system
(b) Time-sharing system
(c) Distributed system
(d) Real time system
2. What is Hardware protection? Describe various operations performed to protect the operating system.
3. Consider the following sequence of memory reference from 460 words programs: 10, 11, 104, 170, 73, 309,
185, 245, 246, 434, 458, 364.
(a) Give the reference string assuming a page size of 100 words.
(b) Find the number of page faults for the above reference string assuming 200 words primary memory
available to the program using LRU replacement algorithm.
4. Describe the various operating system structures with figure.
5. Consider a system with a set of processes P1, P2 and P3 and their CPU burst times, priorities and arrival times
being mentioned as below:
process CPU burst time Arrival time Priority
P1 5 0 2
P2 15 1 3
P3 10 2 1
Assuming 1 to be the highest priority, calculate the following:
(a) Average waiting time using FCFS, SJF (preemptive and non-preemptive) and priority (preemptive and nonpreemptive) scheduling mechanism.
(b) Average turn around time using FCFS, SJF (preemptive and non-preemptive) and priority (preemptive and
non-preemptive) scheduling mechanism.
6. (a) Describe the actions taken by a Kernel to switch context between processes.
(b) What is threading? Compare and contrast user-level thread and Kernel-level threads.
7. Suppose the moving head disk with 200 tracks is currently serving a request for track 143 and has just finished
a request for track 125. If the queue of requests is kept in FIFO order: 86, 147, 91, 177, 94, 150.
What is the total head movement for the following scheduling schemes?
(i) FCFS (ii) SSTF (iii) C-SCAN
8. Write short notes on any two of the following:
(i) File allocation methods
(ii) Interrupt
(iii) Encryption
(iv) Page replacement algorithms.
YEAR 2011
1. What is an operating system? Explain evolution of operating system.
2. Consider the following segment table:
Segment Base Length
0 219 600
1 2300 14
2 90 100
3 1327 580
4 1952 96
3. What are the Physical address for the following logic addresses?
(a) 0,430 (b) 1,10 (c) 2,500 (d) 3,400 (e) 4,112
4. What is process control block? Describe the differences among short-term, medium-term and long-term
scheduling.
5. What do you mean by computer security and how could it be maintained?
6. Consider the set of process given in the table and the following scheduling algorithms:
i) Shortest Job First (SJF)
ii) Shortest Remaining Job First (SRJF)
7. Process ID Arrival time Executive time
A07
B15
C23
D62
E 12 3
If there is a tie within the processes, the tie is broken in the favour of the oldest process. Draw in the Gantt
chart waiting time and trun around time for the two algorithms, comment on your result which one is better
and why?
YEAR 2010
1. Define the following terms :
(a) Online Processing
(b) Virtual Memory
(c) Interrupt
(d) Distributed Operating System
(e) Utilities
2. What is Scheduler? Describe the different types of scheduler with diagram.
3. What is multi-programming? Explain multi-programming with dynamic partition with example and diagram.
Haw it is better multiprogramming with fixed partition?
4. What do understand by free space management? Explain the different methods to implement it.
5. Explain the different features of Linux Operating System.
6. What do you mean by computer security and how could it be maintained?
7. Differentiate be between any two of the following :
(a) Buffering and Spooling
(b) Preemptive and Non-preemptive
(c) Multitasking and multiprocessing
8. Write short notes on any two of the following :
(a) Swapping
(b) Demand Paging
(c) Process Control Block
YEAR 2009
1. Define the following terms :
(a) System Calls
(b) Batch System
(c) Time-sharing system
(d) Direct Memory Access
(e) Paging
2. Briefly explain the four major functions of an operating system.
3. Consider the following set of processes with the length of the CPU burst time given in milliseconds and lower
numbers mean higher priority :
Process Arrival Time (ms) Next Burst (ms) Priority
P1 0 10 5
P2 1 6 4
P3 3 2 2
P4 5 4 0
4. Draw Gantt chart for FCFS, SJF and Priority Scheduling (per-emptive and non-emptive). Also calculate Turn
around Time, Waiting Time and Average Waiting Time for each process for each of the above scheduling
algorithms.
5. Differentiate between :
(a) Logical and Physical Address
(b) Internal and External Fragmentation
6. Prove Belady's anomaly in FIFO Page Replacement Algorithm, assuming that the number of frames is
increased from 3 to 4; the Page Reference String:
1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5
Assume all frames are empty initially.
7. With reference to File-system Interface, explain the different access methods for retaining the information
from the file.
8. Explain the term Disk Scheduling. Briefly explain various disk scheduling algorithms.
9. Write short notes on any two of the following:
(a) Process state
(b) Encryption
(c) Thrashing
(d) Page Fault