N A L A N D A O P E N U N I V E R S I T Y
Master of Computer Application Part-III
PAPER-XXI
(MCS-041 Operating Systems)
Annual Examination, 2017
Time 3 Hours. Full Marks 80
Answer any Five Questions.
All questions carry equal marks.
1. What is a semaphore? Give solution to sleeping barber problem with the help of semaphore.
2. Draw the Gantt chart for the FCFS and SJF policy, considering any four set of processes that
arrive at time with the length of CPU time given in milliseconds. Also calculate the average
waiting and average turnaround time. (Assume four process with variable time period in
milliseconds).
3. What is segmentation? Explain with an example. How segmentation different from paging.
4. Explain algorithm for deadlock prevention. Give a suitable example to explain the algorithm.
5. Give a short note on mutual exclusion in a distributed system. Explain token based mutual
exclusion in the context of it.
6. Implement FCFS, SCAN, LOOK and 8C LOOK scheduling for the following disk queues
50, 91, 150, 42, 130, 98, 18, 138, 140.
Assume that the disk head is initially at cylinder 50. Calculate the total head count.
7. Discuss hardware support in paging. How is overlay different from swapping? Explain.
8. Explain pipes and filters in UNIX (with examples). Give a diagram to explain various states of
a process. Explain the PCB or TCB also.
9. Explain paging address translation by and give suitable diagrams and examples also
Direct Mapping.
Associative Mapping.
10. Give short notes on the following
Disk Organization in UNIX.
DOS and NOS.
Multiprocessor Interconnection.
Macintosh OS.