2022 question paper
Operating System
28 questions
Q1a. Which scheduling policy is most suitable for a time shared operating system: (i) Shortest job first (ii) Round Robin (iii) FCFS (iv) Elevator20222m
Module 2: Processes & Scheduling
View this question on its own page →Which scheduling policy is most suitable for a time shared operating system:
(i) Shortest job first
(ii) Round Robin
(iii) FCFS
(iv) ElevatorQ1b. A process executes the following segment of code: ``c for (i = 1; i <= n; i++) fork(); `` The number of new processes created is: (i) n (ii) (n(n+1))/2 (iii) 2^n - 1 (iv) 2^n20222m
Module 2: Processes & Scheduling
View this question on its own page →A process executes the following segment of code:
for (i = 1; i <= n; i++) fork();The number of new processes created is:
(i) n
(ii) (n(n+1))/2
(iii) 2^n - 1
(iv) 2^nQ1c. ______ is a technique of improving the priority of process waiting in queue for CPU allocation: (i) Starvation (ii) Ageing (iii) Revocation (iv) Relocation20222m
Module 2: Processes & Scheduling
View this question on its own page →______ is a technique of improving the priority of process waiting in queue for CPU allocation:
(i) Starvation
(ii) Ageing
(iii) Revocation
(iv) RelocationQ1d. Interval between the time of submission and first response to the job is called: (i) waiting time (ii) turnaround time (iii) throughput (iv) response time20222m
Module 2: Processes & Scheduling
View this question on its own page →Interval between the time of submission and first response to the job is called:
(i) waiting time
(ii) turnaround time
(iii) throughput
(iv) response timeQ1e. A process is: (i) program in high level language kept on disk (ii) content of main memory (iii) program in execution (iv) job in secondary memory20222m
Module 2: Processes & Scheduling
View this question on its own page →A process is:
(i) program in high level language kept on disk
(ii) content of main memory
(iii) program in execution
(iv) job in secondary memoryQ1f. In which of the following page replacement policy Belady's anomaly occurs? (i) FIFO (ii) LRU (iii) LFU (iv) NRU20222m
Module 5: Memory Management
View this question on its own page →In which of the following page replacement policy Belady's anomaly occurs?
(i) FIFO
(ii) LRU
(iii) LFU
(iv) NRUQ1g. Which of the following approach require knowledge of the system's state in advance. (i) Deadlock detection (ii) Deadlock prevention (iii) Deadlock avoidance (iv) None of these20222m
Module 4: Deadlocks
View this question on its own page →Which of the following approach require knowledge of the system's state in advance.
(i) Deadlock detection
(ii) Deadlock prevention
(iii) Deadlock avoidance
(iv) None of theseQ1h. ______ is the time required to move the disk-arm to the desired track. (i) Seek time (ii) Rotational Latency (iii) Access time (iv) Waiting time20222m
Module 6: I/O & File Management
View this question on its own page →______ is the time required to move the disk-arm to the desired track.
(i) Seek time
(ii) Rotational Latency
(iii) Access time
(iv) Waiting timeQ1i. Which module gives control of the CPU to the process selected by the short-term scheduler? (i) dispatcher (ii) scheduler (iii) Interrupt (iv) None of these20222m
Module 2: Processes & Scheduling
View this question on its own page →Which module gives control of the CPU to the process selected by the short-term scheduler?
(i) dispatcher
(ii) scheduler
(iii) Interrupt
(iv) None of theseQ1j. Which memory allocation policy allocates the largest hole to the process? (i) Best-fit (ii) Worst-fit (iii) First-fit (iv) None of the above.20222m
Module 5: Memory Management
View this question on its own page →Which memory allocation policy allocates the largest hole to the process?
(i) Best-fit
(ii) Worst-fit
(iii) First-fit
(iv) None of the above.Q2a. Describe seek time, rotational latency, random-access time and their relationship in context of magnetic disks by drawing its moving – head mechanism.20227m
Module 6: I/O & File Management
View this question on its own page →Describe seek time, rotational latency, random-access time and their relationship in context of magnetic disks by drawing its moving – head mechanism.
Q2b. Suppose a disk has 100 cylinders, numbered from 0 to 99. At some time the disk arm is at cylinder 50, and there is a queue of disk access requests for cylinders 4, 34, 10, 7, 19, 73, 2, 15, 6 and 20. Assuming that shortest seek-time first (SSTF) is being used for scheduling the disk access. Calculate the total time taken to satisfy all requests if it takes 1 millisecond to move from one cylinder to adjacent one.20227m
Module 6: I/O & File Management
View this question on its own page →Suppose a disk has 100 cylinders, numbered from 0 to 99. At some time the disk arm is at cylinder 50, and there is a queue of disk access requests for cylinders 4, 34, 10, 7, 19, 73, 2, 15, 6 and 20. Assuming that shortest seek-time first (SSTF) is being used for scheduling the disk access. Calculate the total time taken to satisfy all requests if it takes 1 millisecond to move from one cylinder to adjacent one.
Q3a. What do you understand by address binding, Explain the various address binding schemes.20227m
Module 5: Memory Management
View this question on its own page →What do you understand by address binding, Explain the various address binding schemes.
Q3b. Consider the virtual page reference string 0, 4, 8, 20, 24, 36, 44, 12, 68, 72, 80, 84, 28, 32, 88, 92 on a demand paged virtual memory system running on computer system that has main memory of size 4 page frames which one initially empty. The CPU uses LRU page replacement policy. (i) How many page faults does this sequence cause? (ii) What are the page numbers of the pages present in the main memory at the end of the sequence?20227m
Module 5: Memory Management
View this question on its own page →Consider the virtual page reference string 0, 4, 8, 20, 24, 36, 44, 12, 68, 72, 80, 84, 28, 32, 88, 92 on a demand paged virtual memory system running on computer system that has main memory of size 4 page frames which one initially empty. The CPU uses LRU page replacement policy.
(i) How many page faults does this sequence cause?
(ii) What are the page numbers of the pages present in the main memory at the end of the sequence?Q4a. What do you understand by critical section problem. Discuss the requirements that a solution to the critical section problem must satisfy.20227m
Module 3: Inter-process Communication
View this question on its own page →What do you understand by critical section problem. Discuss the requirements that a solution to the critical section problem must satisfy.
Q4b. A single processor system has three resource types X, Y and Z, which are shared by three processes. There are 5 units of each resource type. Consider the following scenario, where the column 'alloc' denotes the number of units of each resource type allocated to each process, and the column request denotes the number of units of each resource type requested by a process in order to complete execution. Find the process that will finish first and last. | | alloc<br>X Y Z | Request<br>X Y Z | |---|---|---| | P0 | 1 2 1 | 1 0 3 | | P1 | 2 0 1 | 0 1 2 | | P2 | 2 2 1 | 1 2 0 |20227m
Module 4: Deadlocks
View this question on its own page →A single processor system has three resource types X, Y and Z, which are shared by three processes. There are 5 units of each resource type. Consider the following scenario, where the column 'alloc' denotes the number of units of each resource type allocated to each process, and the column request denotes the number of units of each resource type requested by a process in order to complete execution. Find the process that will finish first and last.
alloc<br>X Y Z Request<br>X Y Z P0 1 2 1 1 0 3 P1 2 0 1 0 1 2 P2 2 2 1 1 2 0 Q5a. Explain process state transition diagram of an operating system.20227m
Module 2: Processes & Scheduling
View this question on its own page →Explain process state transition diagram of an operating system.
Q5b. Consider the following CPU processes with arrival times 0 and CPU bursts (in milliseconds) as given below: | Process | Burst time | |---|---| | P1 | 24 | | P2 | 3 | | P3 | 3 | If the Round Robin Scheduling is used with time quantum of 4 milliseconds to schedule the processes. Draw the Gantt chart and calculate the average waiting time across all processes (in milliseconds).20227m
Module 2: Processes & Scheduling
View this question on its own page →Consider the following CPU processes with arrival times 0 and CPU bursts (in milliseconds) as given below:
Process Burst time P1 24 P2 3 P3 3 If the Round Robin Scheduling is used with time quantum of 4 milliseconds to schedule the processes. Draw the Gantt chart and calculate the average waiting time across all processes (in milliseconds).
Q6a. Write necessary conditions that must hold simultaneously to arise deadlock situation. Briefly explain different deadlock handling mechanisms.20227m
Module 4: Deadlocks
View this question on its own page →Write necessary conditions that must hold simultaneously to arise deadlock situation. Briefly explain different deadlock handling mechanisms.
Q6b. What is the cause of thrashing? How does the system detect thrashing and once detected what can the system do to eliminate it20227m
Module 5: Memory Management
View this question on its own page →What is the cause of thrashing? How does the system detect thrashing and once detected what can the system do to eliminate it
Q7a. What do you understand by fragmentation. Explain the difference between internal and external fragmentation.20227m
Module 5: Memory Management
View this question on its own page →What do you understand by fragmentation. Explain the difference between internal and external fragmentation.
Q7b. Consider a paging hardware with a TLB. Assume that the entire page table and all the pages are in the physical memory. It takes 10 milliseconds to search the TLB and 80 milliseconds to access the physical memory. If the TLB hit ratio is 0.6, find the effective memory access time (in milliseconds).20227m
Module 5: Memory Management
View this question on its own page →Consider a paging hardware with a TLB. Assume that the entire page table and all the pages are in the physical memory. It takes 10 milliseconds to search the TLB and 80 milliseconds to access the physical memory. If the TLB hit ratio is 0.6, find the effective memory access time (in milliseconds).
Q8a. What is thread? Explain the benefits of using thread.20227m
Module 2: Processes & Scheduling
View this question on its own page →What is thread? Explain the benefits of using thread.
Q8b. Explain the use of TLB in paging hardware and its benefits.20227m
Module 5: Memory Management
View this question on its own page →Explain the use of TLB in paging hardware and its benefits.
Q9a. Write short notes on: Banker's Algorithm20227m
Q9b. Write short notes on: Paging20227m
Q9c. Write short notes on: Process Control Block20227m
Module 2: Processes & Scheduling
View this question on its own page →Write short notes on: Process Control Block
Q9d. Write short notes on: Peterson's solution20227m
Module 3: Inter-process Communication
View this question on its own page →Write short notes on: Peterson's solution