Group B

Attempt any Six question

2. What is an operating System? Explain the functions of operating system

3. Define the term semaphore. How does semaphore help in dining philosopher problem

4. A system has two process and three resources. Each process needs a maximum of two resources is deadlock possible? Explain with answer.

5. Suppose a new process in a system arrives at an average of siz process per minute and each such process requires an average of 8 seconds of service time. Estimate the fraction of time the CPU is busy in a system with a single processor.

6. Given references to the following pages by a program,
0,9,0,18,1,8,7,8,7,1,2,8,2,7,8,2,3,8,3
How many page faults will occur if the program has three page frames for each of following algorithms?
(a) FIFO
(b) LRU

7. What is file? Explain how access control matrix provides resource protection that may access process.

8. What do you mean by one-time password authentication? How worms are different from virus?

Group C

Attempt any Two question

9. Write CPU Scheduling criteria. For the processes listed in following table, draw Gantt chart illustrating their executrion and calculate average waiting time and turnaround time using.
a) First come First Serve
b) Shortest Remaining Time Next
c) Priority
d) Round Robin (quantum = 1sec)

10. Define the term seek time and rotational delay in disk scheduling. Suppose that the disk has 100 cylinders, numbered 0 to 99. The drive is currently serving a request at cylinder 43 and previous request was at cylinder 25. The queue of pending request, in FIFO order is: 86, 70,13,74,48,9,50,30 Starting from current head position, what is total distance (in cylinders) that the disk arm moves to satisfy all pending request for each of following disk scheduling algorithms?
a) FCFS
b) SSTF
c) SCAN
d) LOOK

11. What is clock synchronization? Explain how physical clock synchronizes by Berkeley algorithm and logical clock synchronize by lamport\'s algorithm with suitable example.