CSIT 4th Semester
Operating Systems Board Question Paper 2081

CSC 264-2081 ✡
Tribhuvan University
Institute of Science and Technology
2081
✡
Bachelor Level/Second Year/Fourth Semester/Science
Computer Science Information Technology (CSC 264)
(Operating Systems)
(New Course)
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.

Explain the translation of logical address into physical address using segment table with necessary diagram. List advantages and disadvantages of segmentation.

2.

Find the seek time using SCAN, C-SCAN, Look and C-Look disk scheduling algorithm for processing the following requests queue:
35, 70, 45, 15, 65, 20, 80, 90, 75, 130.
Suppose the disk has tracks numbered from 0 to 150 and assume the disk arm to be at 30 and moving outward.

3.

Explain Sleeping Barber problem. Illustrate on how it can be solved.

Section B

Attempt any Eight questions

[8x5=40]
4.

Explain microkernels and exokernels.

5.

Consider a swapping system in which memory consists of the following hole sizes in memory order 15 MB, 2 MB, 10 MB, 6 MB, 8 MB and 20 MB. Which hole is taken for successive segment requests of
a) 6 MB
b) 10 MB
c) 8 MB
for first fit, next fit and best fit.

6.

Explain how semaphore solves the problem of critical section?

7.

How do you think deadlock can be avoided? Explain.

8.

Explain Inter-Process Communication in Linux.

9.

List different file structures and explain them.

10.

Calculate the average waiting time and turn around time using priority algorithm (priority 1 being the highest) for the given scenario:

PIDBurst Time (s)Arrival TimePriority
A403
B223
C422
D231

11.

Explain memory mapped IO.

12.

Write short notes on
a) Virtual memory
b) Race condition