Govt. of Karnataka, Department of Technical Education
Diploma in Computer Science & Engineering
Subject: Operating System
Max. Marks: 100 Max. Time: 3 Hours
Model Question Paper
Note: 1. Section –I is compulsory.
2. Answer any TWO questions from each remaining Sections. Marks
Section – I
1. a) Fill in the blanks with appropriate word/s 5x1=5
i. The program in execution is …………….
ii. A new process is created by ………….
iii . ………. is the number of processes that are executed per unit.
iv. In two-level directory structure, each user has ………….
v. The file system implementation is done through ………….
b) Write a note on Protection and security. 5
Section – II
2. a) What are the advantages of multiprocessor systems? Explain. 5
b) Explain clustered systems. 5
c) Distinguish between traditional computing and client server computing. 5
3. a) Define the process. Explain the process states with diagram. 6
b) Differentiate between long term scheduler v/s c p u scheduler. 4
c) What are the reasons for process co operation? Explain. 5
4. a) Which are the CPU scheduling criteria? Explain 5
b) Consider the following set processes, with the length of CPU burst 10
given in milliseconds:
Process Burst time Priority
P1 10 3
P2 1 1
P3 2 3
P4 1 4
P5 5 2
The processes are assumed to have arrived in the order p1, p2, p3, p4, p5 all at time 0.
i). Draw the Gantt charts for FCFS and priority scheduling.
ii). What is the turnaround time for each process for each of scheduling
algorithms in part i ?
iii). Calculate average waiting time of each process.
Section – III
5. a) Explain how solve the problem of critical-section through semaphores 5
b) Explain the four necessary conditions for deadlock. 8
c) What do you mean by deadlock avoidance? 2
6. a) What is the significance of swapping ? Explain. 5
b) Explain in detail the paging memory management scheme. 10
7. a) Explain first-fit ,best-fit and worst-fit strategies for memory allocation . 6
b) What is the user view of segmentation? Explain. 5
c) Explain the concept of virtual memory. 4
Section – IV
8. a) Consider the following page reference string
How many page faults would occur for the following replacement algorithms,
assuming 4 page frames ?
i) LRU replacement
ii) FIFO replacement
iii) Optimal replacement 10
b) What is a file? Explain its attributes. 5
9. a) What are the operations performed on a directory ? Explain. 6
b) Explain two-level and tree-structured directories. 9
10. a) How to implement a file system ? Explain in detail . 9
b) What is the significance of the virtual file system? Explain. 6