BIT 3rd Semester
Operating System Board Question Paper 2080

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BIT 204-2080 ✡
Tribhuvan University
Institute of Science and Technology
2080
✡
Bachelor Level/Second Year/Third Semester/Science
Bachelors in Information Technology (BIT 204)
(Operating System)
Full Marks:60 Pass Marks:24 Time:3 hours

Candidates are required to give their answers in their own words as for as practicable.
The figures in the margin indicate full marks

Section A
Long Answer Questions
Attempt any Two question.
[2x10=20]
1.

Why Optimal Page Replacement is best but not practically feasible page replacement algorithm?
Calculate the number of page faults for Optimal, LRU and FIFO replacement algorithm for the reference string: 1, 3, 4, 2, 3, 5, 4, 3, 1, 2, 4, 6, 3, 2, 1, 4, 2 using 3 page frames.

2.

Find Average waiting time and turn-around time for following example using FIFO, SRTF and Round Robin scheduling algorithm. Assume quantum as 4 ms.

Process idArrival timeBurst time(ms)
P108
P215
P3110
P4213
P5217

3.

Why virtual memory technique is used in the computer system? What is logical address? Explain the process of conversion of logical address to physical address using TLB.

Section B

Attempt any Eight questions

[8x5=40]
4.

Suppose that a disk drive has the cylinder numbered, 0 to 199 is currently serving a request at cylinder 143. The request queue is kept in the FIFO order 25, 17, 119, 197, 194, 15, 182, 115, and 183. What is the total head movement needed to satisfy these request for the following disk scheduling algorithm.
a) FCFS
b) SSTF

5.

If a 2gb disk has 4-KB block size, calculate the size of the file allocation table if each entry of the table is 4 bytes.

6.

What is process? Explain 3 state process models with suitable diagram.

7.

Write down the basic difference between coalescing and compaction with diagram.

8.

What is memory mapped I/O? Explain about device independent I/O software.

9.

Differentiate between deadlock and starvation? Discuss the process of detecting deadlocks when there are multiple resources of each type.

10.

Differentiate between process and a program. What is PCB?

11.

Write down the Solving technique of the producer consumer problem with Message passing?

12.

What is system call? Explain the system call process in detail.