1) A hard disk which is having 500 cylinders, numbered from 0 to 499. The drive is presently serving the request at cylinder 143, and the previous request was at cylinder 125. Status of queue is as follows: 86, 470, 13, 177, 448, 150, 102, 175, 130. What is the total distance (in cylinders) that disk arm moves to satisfy all the pending requests for each of the disk-scheduling algorithms given below?

a. FCFS
b. SSTF
c. SCAN
d. LOOK

2) Operating system provides the environment for execution of programs. prepare down the services that are provided for the convenience of the programmer, to make programming task easier? Describe the services in detail.

a) prepare down different Execution modes in the Operating System.

b) What do you mean by a System call? Describe the different kinds of system calls

3) In general a Process can be divided into Single Threaded Process and Multi Threaded Process.

a) prepare down the benefits of multithreaded programming.

b) Describe the Multithreading Models with suitable diagram.

c) Describe Round robin scheduling with an ex.

4)a) What do you mean by Critical Section? describe in detail with suitable ex.

b) There are few classical problems of synchronization and these problems are exs of a large class of concurrency–control problems. One of the problems is Dining-Philosophers problem. Describe this problem with suitable ex. prepare the Monitor solution for this problem.

5) Describe the Banker’s algorithm for deadlock avoidance with suitable ex.

6) Paging is the memory management scheme. Sketch the Paging hardware diagram. prepare down the working procedure of paging hardware in detail.

7) How can you handle the page fault in demand paging? Describe FIFO page replacement and Optimal Page replacement algorithms in detail.

8) Describe the different diskspace allocation methods.

9) Describe the different disk scheduling algorithms in detail with suitable ex.