AD-405 Operating Systems - Nov 2023 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aExplain the evolution of operating system in detail.
   How to answer

   • Define operating system and need for evolution
   • Explain serial/batch, multiprogramming, time-sharing stages
   • Explain personal, parallel, distributed, real-time and mobile OS developments
   • Summarize goals: efficiency, convenience, resource management
2. 7 Marks
   bExplain the concept of buffering and spooling.
   How to answer

   • Define buffering and spooling
   • Explain types of buffering and buffer management
   • Explain spooling with printer example
   • Differentiate purpose and concurrency handling
3. 7 Marks
   aWhat is a File? Write different file attributes and operations?
   How to answer

   • Define file as logical storage unit
   • List file attributes: name, type, size, protection etc.
   • List file operations: create, read, write, delete etc.
   • Brief purpose of file system management
4. 7 Marks
   bCompare the following CPU scheduling algorithms, highlighting the strengths and limitation of each algorithms.

   1. i)FCFS
   2. ii)SRTF
   How to answer

   • Define CPU scheduling and criteria
   • Explain FCFS working, strengths and limitations
   • Explain SRTF working, strengths and limitations
   • Compare on preemption, waiting time, starvation, convoy effect
5. 7 Marks
   aExplain disk structure. How data read and write form/on disk?
   How to answer

   • Define disk structure: platters, tracks, sectors, cylinders
   • Explain read/write heads and disk controller
   • Explain read/write process with seeking and rotation
   • Include diagram of disk geometry
6. 7 Marks
   bWhat is the Difference between SCAN and LOOK Disk scheduling algorithms?
   How to answer

   • Define SCAN elevator movement to disk ends
   • Define LOOK movement only to last request
   • Compare arm movement, waiting time and efficiency
   • Give example movement sequence
7. 7 Marks
   aWhat is process state? Explain state transition diagram.
   How to answer

   • Define process state
   • List states: new, ready, running, waiting, terminated
   • Explain transitions with diagram
   • Explain schedulers role in transitions
8. 7 Marks
   bExplain Thread Control Block.
   How to answer

   • Define Thread Control Block
   • List fields: thread ID, state, registers, stack, priority
   • Explain per-thread vs per-process information
   • Compare with Process Control Block
9. 7 Marks
   aDescribe about how recovery from deadlock?
   How to answer

   • Define deadlock recovery concept
   • Explain process termination: abort all / one by one
   • Explain resource preemption and rollback
   • Discuss selection criteria: priority, cost
10. 7 Marks
    bWhat is Segmentation? Explain virtual to physical address mapping in a segmented system with the help of a diagram.
    How to answer

    • Define segmentation and segment table
    • Explain segment number and offset addressing
    • Explain limit checking and physical address generation
    • Include diagram of virtual to physical mapping
11. 7 Marks
    aWrite a semaphore solution for dining philosopher's problem.
    How to answer

    • State dining philosophers problem with 5 philosophers
    • Define semaphores: chopsticks and mutex
    • Give wait/signal steps for pickup and putdown
    • Explain deadlock avoidance and starvation handling
12. 7 Marks
    bHow many page faults does the LRU, FIFO and Optimal page replacement algorithm produce 7 1 2 0 3 0 4 2 3 0 3 2 1 2 0 1 7 0 1 assume frame size is 3?
    How to answer

    • State reference string 7 1 2 0 3 0 4 2 3 0 3 2 1 2 0 1 7 0 1 and 3 frames
    • Simulate FIFO and count faults
    • Simulate LRU and count faults
    • Simulate Optimal and count faults and compare
13. 7 Marks
    aExplain virtual memory in operating system. Discuss the advantages and disadvantages of non contiguous storage allocation.
    How to answer

    • Define virtual memory and demand paging
    • Explain advantages of non-contiguous allocation
    • Explain disadvantages: overhead, fragmentation, complexity
    • Compare contiguous vs non-contiguous
14. 7 Marks
    bDiscuss the design issues of distributed operating system.
    How to answer

    • Define distributed operating system
    • Discuss transparency, communication, reliability issues
    • Discuss scalability, heterogeneity, security issues
    • Summarize design trade-offs
15. 14 Marks
    Write short notes:

    1. a)Worms and Virus
    2. b)Demand paging
    3. c)Batch processing
    4. d)Time-sharing
    How to answer

    • Define worms vs virus characteristics
    • Explain demand paging mechanism
    • Explain batch processing and time-sharing
    • Give examples and advantages for each