Cc D1032 Pages: 2

Reg No.:_ Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FOURTH SEMESTER B.TECH DEGREE EXAMINATION(R&S), MAY 2019
Course Code: CS204
Course Name: OPERATING SYSTEMS (CS)

Max. Marks: 100 Duration: 3 Hours

PARTA

Answer all questions. Each carries 3 marks.

1 What is the need for system calls in Operating System? 3
2 How does the hardware find the Operating System 121001 after system switch-on? 3
3 The long term scheduler directly affectsthe system performance. Explain how. 3
4 Differentiate thread from a process. 3

PART 13

Answer any two questions. Each carries 9 marks.

5 Explain the Kernel data structures with suitable example. 9
6 With the help of a diagram explain the different states of a process.
7 A writer process like to send some bulk information to a reader process. Explain 9

the IPC mechanism that can be used for the purpose.
PART C
Answer all questions. Each carries 3 marks.

8 What is the difference between counting and binary semaphores? 3
9 Explain the syntax of a monitor. 3
10 What is preemptive scheduling? Give one disadvantage of preemptive scheduling. 3
11 What are the necessary conditions that cause deadlock in a system? 3
PART 0
Answer any two questions. Each carries 9 marks.
12 Write an algorithm that satisfies all the critical-section requirements for n process. 9
13 Find the average waiting time and average turnaround time for the processes given 9

in the table below using:- i) SRT scheduling algorithm ii) Priority scheduling

algorithm

Priority

Page 1 of 2