RGPV OS

OS Question Bank-Solution with explanation
Contains most asked questions from previous years examinations (Operating Systems).


Q1. What do you mean by Virtual Memory? Write down its advantages?

Q2. Compare Paging and Segmentation?

Q3. What is Process Scheduling, CPU Scheduling, Disk Scheduling? Explain Short, Medium and Long term Scheduler?

Q4. Explain concept of a process with its components.

Q5. Explain the following in brief Contiguous and Linked list allocation for implementing file system?

Q6. Explain various Disk scheduling algorithms with Illustrations.

Q7. Define process and thread. What is PCB? Explain its various entries with their usefulness?

Q8. Discuss advantages and disadvantages of the Buffer cache?

Q9. Explain different types of OS with examples of each.

Q10. What is an Operating System? Write down its desirable characteristics?

Q11. Wrtie short notes
       a)      Multi processor operating system
       b)      Distributes operating system
       c)       Threads
       d)      File protection

Q12. Define a deadlock? Write down the conditions responsible for deadlock? How can we recover from deadlock?

Q13. What are the various services provided by Operating system?

Q14. What do you mean by PCB? Where is it used? What are its contents? Explain.

Q15. What is Binary and Counting semaphores?

Q16. What is File? What are the different File attribute and operations?

Q17. What are System call? Explain briefly about various types of system call provided by an Operating System?

Q18. Describe necessary conditions for deadlocks situation to arise.

Q19. Consider the ahead set of processes with the length of CPU burst time given in  “m” sec-
Process
CPU Burst Time
Priority
P1
9
3
P2
3
1
P3
2
4
P4
5
2
The processes are assumed in the order P1, P2, P3, P4 with initial time zero. Calculate average waiting time and average turnaround time for the Priority CPU scheduling algorithm.

Q20. What are points to be consider in file system design? Explain linked list allocation in detail?

Q21. Write a Semaphore solution for dining Philosopher’s problem?

Q22. Briefly explain the following: (11:30 to 12:00)
      1)      Mutual exclusion
      2)      Critical section problem

Q23. Consider the following page reference string:
1,2,3,4,5,3,4,1,2,7,8,7,8,9,7,8,9,5,4,5. How many page faults would occur for the following replacement algorithm, assuming four frames:
      a)      FIFO
      b)      LRU

Q24. What do you mean by Contiguous Memory Allocation?

Q25. Describe Deadlock Handling in OS?

Q26. Explain CPU schedulers in operating system?

Q27. What is PCB in operating system?

Q28. Write the different state of a process with the help of Process state deagram?

Q29.  Consider the following snapshot of a system.
Answer the following questions using Bankers algorithm-
(i) What is the content of the matrix need?
(b) Is the system in a safe state?
(iii) If a request from process P1 arrives for (0, 4, 2, 0) can the request be granted immediately?

Q30. Consider a disk queue with requests for I/O to blocks on cylinders 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. The CLOOK scheduling algorithm is used. The head is initially at cylinder number  143. The cylinders are numbered from 0 to 4999. Find-
(a) Total head movement?
(b) Total seek time, if seek takes 2msec/cylinder move?

Q31. Consider a disk queue with requests for I/O to blocks on cylinders 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. The LOOK disk scheduling algorithm is used. The head is initially at cylinder number  143. The cylinders are numbered from 0 to 4999. Find-
(a) Total head movement?
(b) Total seek time, if seek takes 2msec/cylinder move?

Q32. Consider a disk queue with requests for I/O to blocks on cylinders 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. The C-SCAN disk scheduling algorithm is used. The head is initially at cylinder number  143. The cylinders are numbered from 0 to 4999. Find-
(a) Total head movement?
(b) Total seek time, if seek takes 2msec/cylinder move?

Q33. Consider a disk queue with requests for I/O to blocks on cylinders 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. The SCAN disk scheduling algorithm is used. The head is initially at cylinder number  143. The cylinders are numbered from 0 to 4999. Find-
(a) Total head movement?
(b) Total seek time, if seek takes 2msec/cylinder move?

Q34. Consider a disk queue with requests for I/O to blocks on cylinders 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. The SSTF disk scheduling algorithm is used. The head is initially at cylinder number  143. The cylinders are numbered from 0 to 4999. Find-
(a) Total head movement?
(b) Total seek time, if seek takes 2msec/cylinder move?

Q35. Consider a disk queue with requests for I/O to blocks on cylinders 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. The FCFS disk scheduling algorithm is used. The head is initially at cylinder number  143. The cylinders are numbered from 0 to 4999. Find-
(a) Total head movement?
(b) Total seek time, if seek takes 2msec/cylinder move?

Q36. Consider the following page reference string-
0, 1, 1, 2, 3, 4, 3, 3, 1, 0, 2.
How many page fault and page hit would occur for the LRU page replacement algorithm, assuming 4 frames being made available?

Q37. Consider the following page reference string-
0, 1, 1, 2, 3, 4, 3, 3, 1, 0, 2.
How many page fault and page hit would occur for the OPTIMAL  page replacement algorithm, assuming 4 frames being made available?

Q38. Consider the following page reference string-
0, 1, 1, 2, 3, 4, 3, 3, 1, 0, 2.
How many page fault and page hit would occur for the MRU page replacement algorithm, assuming 4 frames being made available?

Q39. Consider the following page reference string-
0, 1, 7, 2, 3, 2, 7, 1, 0, 3.
How many page fault and page hit would occur for the FIFO page replacement algorithm, assuming 4 frames being made available?

Q40. Consider the following processes and the related data-
Process
Arrival Time
CPU Burst Time
P1
0
8
P2
3
7
P3
5
6
P4
8
4
Using Round Robin CPU scheduling algorithm draw Gantt chart and calculate average waiting time, average turnaround time, average response time and throughput?

Q41. Consider the following processes and the related data-
Process
Arrival Time
CPU Burst Time
P1
0
20
P2
3
7
P3
5
6
P4
10
10
Using SJF non preemptive CPU scheduling algorithm draw Gantt chart and calculate average waiting time, average turnaround time, average response time and throughput?

Q42. Consider the following processes and the related data-
Process
Arrival Time
CPU Burst Time
P1
0
20
P2
3
7
P3
5
6
P4
10
10
Using SJF preemptive CPU scheduling algorithm draw Gantt chart and calculate average waiting time, average turnaround time, average response time and throughput?

Q43. Consider the following processes and the related data-
Process
Arrival Time
CPU Burst Time
P1
0
8
P2
2
5
P3
3
9
P4
4
3
Using SRTF (SJF preemptive) CPU scheduling algorithm draw Gantt chart and calculate average waiting time, average turnaround time, average response time and throughput?

Q44. What is Mutex in operating system?

Q45. Explain Network operating system?

Q46. What do you mean by paging in operating system.