Operating System

Operating system

Time : three hours MM – 80
Note :- Attempt five questions in all, selecting exactly one from each of the secations A, B, C and D. section E is compulsory.

Section A
1. Explain :
(a) Simple Batch system
(b) Multi-Programmed batch system
(c) Time sharing system. 12
2. Explain the difference and relationship between a program and a process. Is this difference important in serial (single process) operating system ? Why or why not ? 12

Section B
3. Distinguish between interrupt driven i/o and DMA.
4. Following is the information related to process workload :
Processes Burst-time (in ms)
P1 21
P2 13
P3 10
P4 8
P5 6
Compute the waiting time for (a) FCFS (b) SJF (c ) Round robin (quantum=10).

Section C
5. What are Semaphores ? explain the critical section problem. 12
6. Define deadlock . what are the necessary conditions of a deadlock ? discuss in detail.12

Section –D
7. Discuss various directory structure along with their relative advantages and disadvantages .
8. Distinguish between :-
(a) Authorization and authentication
(b) Protection and security
(c) File and directory.
9. (a) What is the principal disadvantage of too much multi-programming ?
(b) what are two main operating system functions ?
(c) what is the main difference between multi-programming and time-sharing ?
(d) what are device drivers ?
(e) what is the difference between pre-emptive and non-pre emptive scheduling ?
(f) name the conditions for the occurrence of a deadlock.
(g) what is a safe state ?
(h) what are semaphores?
(i) what is virtual memory ?
(j) what is the difference between authorization and authentication ?
(k) what is a thread ?
(l) why directory structure is acyclic graph type ?
(m) what is process control block (PCB) ?
(n) what are processes and resources ?
(o) what are Coordinating processes ?
(p) what is cryptology ? 16*2=32