Pokhara University
Bachelor of Engineering in Computer Engineering
Semester 3 · PU Spring 2024
Course Title: Operating System
Candidates are required to give their answers in their own words as far as practicable.
- 1.15
- a) Define operating system. Discuss on different types of operating system.
- b) How CPU switches from one process to another? Illustrate with a diagram. What is switching overhead?
OR
Explain Dining Philosopher Problem in process synchronization and give solutions to it.
- 2.15
- a) Given the following set of information, calculate the average waiting time and average turn-around time using SRTN, FCFS, RR (Quantum = 2). Also discuss which algorithm works best. Process Arrival Service Time (Burst es re rp [| 3 | 3s fp f « | 9 id
- b) Define process. Explain PCB, process states and its transition with figures.
- 3.15
- a) Define page fault. Consider the following page reference strings: 1,3, 4, 5,3. 1.6, 7,3, 1. 3,4, 8. 9, 4, 3, 1, 3, 4, 7. How many page faults would occur for each of the following page replacement algorithms assuming 3 pages a frame? In each case calculate fault ratio.
- i) | Second Chance page replacement
- ii) LRU page replacement
- iii) | Optimal page replacement
- b) Define coalescing and compaction. Explain the necessity of inverted — page tables.
OR
What is difference between Paging and Segmentation? What are different page-table structures? Explain anyone.
Answer comingAlso asked in 2023
- 4.15
- a) Whatis internal and external fragmentation? Explain TLB in detail.
- b) Consider following snapshot of a system. BUBO SRE H Oa joo fs fu fa fe [fa fe fo [2 fda ef a fn fae ea ebb ehhh pt fra fo fs |e fo fa [of P Ca CE Answer the following questions using Banker's algorithm:
- i) | What is the content of the matrix needed?
- ii) Is the system ina safe state? Also find the safe sequence.
- 5.8
- a) What'are different ways to input output? Explain Interrupt-Driven “7 V/O with diagram.
- b) How files and directories are stored in memory such that they canbe managed efficiently. Explain the approaches.
- 6.15
- a) Define bottleneck. Explain the concept of cloud OS.
- b) What is cloud operating system? Discuss its characteristics and = advantages.
- 7.
Write short notes on: (Any two) 2x5
- a) Kernel and its types
- b) Mobile OS
- c) Memory hierarchy ea e 7 Brie rr " ' Se a
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