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Operating System Unit 3 – CPU Scheduling and Deadlock: AKTU previous year questions

37 AKTU questions from Unit 3 (CPU Scheduling and Deadlock) asked in 2018–2025, tagged by marks, year and topic. In short: about 36 marks of every paper come from this unit; the most asked topic is CPU Scheduling (22 times); 25 questions came back in a later year. The latest ones are listed below; on the page you can filter them by 2-mark or long questions, topic and repeats.

Unit 3 previous year questions

  • A system has 3 processors and 5 programs ready for execution. In how many ways can the processors be assigned to the programs assuming each processor executes one program at a time? (2 marks, 2025, CPU Scheduling)
  • List three components stored in a PCB. (2 marks, 2025, CPU Scheduling)
  • Explain the process concept in detail with its states and state transition diagram. (7 marks, 2025, CPU Scheduling)
  • Consider the set of processes with arrival time (in milliseconds), CPU burst time (in milliseconds), and priority (0 is the highest priority) shown below. P1(AT=0,BT=11,Pri=2), P2(AT=5,BT=28,Pri=0), P3(AT=12,BT=2,Pri=3), P4(AT=2,BT=10,Pri=1), P5(AT=9,BT=16,Pri=4). Draw the Gantt chart and find average waiting time using preemptive priority scheduling algorithm. (7 marks, 2025, CPU Scheduling)
  • Compare and contrast FCFS, SJF, and Round Robin scheduling algorithms. (7 marks, 2025, CPU Scheduling)
  • Two semaphores S1 and S2 are both initialized to 1. Process P1 executes wait(S1); wait(S2); and P2 executes wait(S2); wait(S1);. Explain how a deadlock may occur and under what sequence. (7 marks, 2025, Deadlock)
  • A system shares 9 tape drives. Current allocation and maximum requirement: P1(alloc=3, max=7), P2(alloc=1, max=6), P3(alloc=3, max=5). Which of the following best describes current state: 1. Safe, Deadlocked 2. Safe, Not Deadlocked 3. Not Safe, Deadlocked 4. Not Safe, Not deadlocked. Explain. (7 marks, 2025, Deadlock)
  • Define a process state? (2 marks, 2024, CPU Scheduling)
  • Name one piece of process identification information? (2 marks, 2024, CPU Scheduling)
  • Explain the structure and contents of a Process Control Block (PCB)? (7 marks, 2024, CPU Scheduling)
  • Explore the concept of deadlock and how it can occur in concurrent systems, discussing prevention and avoidance techniques? (7 marks, 2024, Deadlock)
  • Evaluate strategies for deadlock prevention, avoidance, detection, and recovery in concurrent systems, highlighting their effectiveness and trade-offs? (7 marks, 2024, Deadlock)

Most asked Unit 3 topics

  • CPU Scheduling – asked 22 times
  • Deadlock – asked 14 times
  • Threads and Management – asked 1 times

Unit 3 question pattern

  • 2-mark questions: 13 asked in 2018–2025
  • 7-mark questions: 16 asked in 2018–2025
  • 10-mark questions: 8 asked in 2018–2025
  • About 36 marks from Unit 3 in every paper
  • 25 questions were asked again in a later year

Unit 3 questions year by year

  • 2025: 7 Unit 3 questions asked (39 marks across that year's papers)
  • 2024: 6 Unit 3 questions asked (32 marks across that year's papers)
  • 2023: 6 Unit 3 questions asked (52 marks across that year's papers)
  • 2022: 6 Unit 3 questions asked (36 marks across that year's papers)
  • 2019: 6 Unit 3 questions asked (27 marks across that year's papers)
  • 2018: 6 Unit 3 questions asked (32 marks across that year's papers)