PYQ Analysis and Exam Preparation
A deep, strategic analysis of university exams from 2019 to 2024. Discover the guaranteed numericals, theoretical heavyweights, and tricky objective questions you must master to pass.
Learning Goals
- Identify the highest-yield theoretical topics (PCB, State Diagrams, Threads) that consistently appear for 7-14 marks.
- Understand the critical importance of practicing Gantt charts for SJF and Round Robin.
- Master tricky 2-mark objective questions involving state transitions and the fork() system call.
Deep Trend Analysis: The Exam Blueprint
An analysis of 27 exam questions spanning from 2019 to 2024 reveals a highly predictable pattern for Module 2. If you want to score maximum marks, your preparation should focus heavily on three distinct areas.
1. The Guaranteed Numerical (7–14 Marks)
Every single year, without exception, features a major numerical question requiring you to draw a Gantt chart and calculate Average Waiting Time (AWT) and Turnaround Time (TAT).
- The Favorites: The examiners overwhelmingly favor Round Robin (tested in 2022 and 2023) and Shortest Job First (SJF), specifically asking to compare Non-Preemptive vs. Preemptive (SRTF) versions (tested in 2019 and 2024).
2. The Theoretical Heavyweights (7 Marks)
Do not walk into the exam without memorizing the answers to these three topics:
- Process Control Block (PCB): Appeared in 2019, 2022, and 2023. You must be able to draw the PCB structure and explain its fields.
- Process State Transition Diagram: Appeared in 2022 and 2023. You must draw the 5-state or 7-state model flawlessly.
- Threads vs. Processes / User vs. Kernel Threads: Appeared heavily in 2019, 2023, and 2024.
3. The 2-Mark Vocabulary Traps
The short-answer questions are designed to test your precise understanding of OS vocabulary. Frequent targets include:
- The difference between the Short-Term Scheduler (selects the process) and the Dispatcher (actually gives it control of the CPU).
- Ageing: The specific technique used to solve Starvation in priority scheduling.
Knowledge Check
[2022] A process executes the following code: for (i = 1; i <= n; i++) fork(); The number of new processes created is:
High-Yield Subjective Bank
To pass this module, ensure you have a written, 200-word response prepared for the following recurring questions:
- [2022, 2023] Explain the different states of a process during its life cycle using a transition diagram.
- [2019, 2022, 2023] What is a Process Control Block (PCB)? Write short notes detailing its components.
- [2023, 2024] What are the two differences between a user-level thread and a kernel-level thread? Under what circumstance is one type better than the other?
- [2019, 2024] Describe the fundamental role of "Process Scheduling" in a multiprogramming operating system. Identify and explain at least three scheduling criteria (e.g., throughput, turnaround time).
The Ultimate Numerical Challenge
If you can solve this 14-mark question from the 2019 exam, you are ready for the numerical portion of the test.
Problem Statement: Consider the following process arrivals:
- P1: Arrival = 0.0, Burst = 7
- P2: Arrival = 2.0, Burst = 4
- P3: Arrival = 4.0, Burst = 1
- P4: Arrival = 5.0, Burst = 4
Your Task: Draw the Gantt charts and calculate the Average Waiting Time (AWT) and Average Turnaround Time (TAT) for both:
- Non-Preemptive SJF
- Preemptive SJF (SRTF)
Hint for Preemptive SJF: At time 2.0, P2 arrives. Does it preempt P1? At time 4.0, P3 arrives. Does it preempt the current running process? Pay close attention to remaining burst times!
To view complete PYQ, go here: https://pyqdeck.in/it/it_sem5/it_sem5_106503/practice/chapter