Mumbai university question papers Computer science
4th Sem Operating System
Question No.1 is compulsory.
Attempt any four questions out of remaining six questions.
[Total Marks: 100
1. a) What is an operating system? Explain in brief the different services which It
b) bExplain differentsystemcalls of O.S. .
. ihDifferentiatemonolithic.andlayeredstmcture ofO.S.
2 a) Consider the following set of processes with the length of cpu burst given in .
Process Burst time Priority
P1 10 3 ”
P2 1 1
P3 2 4
P4 1 2
P5 5 2
The processes are assumed to have arrived in the order pI, p2, p3, p4, p5 at time O.
i”) Draw the Gantt chart for FCFS, SJF, Priority and Round Robin (Quantu,-n=l).
ii) Which algorithm results in the maximum average waiting time? “10
b) Explain multilevel queue scheduling. Jo
3. a) What is deadlock? Explain various deadlock prevention techniques.
b) Explain critical section problem and its different solutions.
4. a) Explain paging in detail. Describe how logical address converted to physical
b) Calculate Hit and Faults using various page replacement 1.’t)
policies.(FIFO,LRU,OPT). for the following page sequence:
” (The page frame size is 3). ” .
S. a) Explain different techniques of disk scheduling.
b) Explain process concurrency/synchronization pfwindows O.S.
6. a) Explain file allocation in detail. ”
b) Explain how memory management takes place in Linux.
7. Write short notes on ~-
i) Semaphore –
ii) Unix File System
iv) Distributed O.S.