FINAL TERM EXAMINATION
Spring 2010
CS604- Operating Systems (Session - 4)
Time: 90 min
Marks: 60
Question No: 23 ( Marks: 1 ) - Please choose one
The size of pages and frames are same in logical memory and physical memory respectively.
► True
► False
Question No: 24 ( Marks: 1 ) - Please choose one
A modification of free-list approach in free space managment is to store the addresses of n free blocks in the first free block. Known as ______.
► counting
► linked list
► bit vector
► grouping
Question No: 25 ( Marks: 1 ) - Please choose one
In deadlock detection and recovery algorithm, a deadlock exists in the system if and only if the wait for graph contains a _____________
► Cycle
► Graph
► Edge
► Node
Question No: 26 ( Marks: 1 ) - Please choose one
Intel is basically designed for following Operating Systems except __________.
► MULTICS
► OS/2
► Windows
► Linux
Question No: 27 ( Marks: 1 ) - Please choose one
Following is NOT true about Virtual memory.
► Virtual memory help in executing bigger programs even greater in size that of main memory.
► Virtual memory makes the processes to stuck when the collective size of all the processes becomes greater than the size of main memory.
► Virtual memory also allows files and memory to be shared by several different processes through page sharing.
► Virtual memory makes the task of programming easier because the programmer need not worry about the amount of physical memory,
Question No: 28 ( Marks: 1 ) - Please choose one
The execution of critical sections must NOT be mutually exclusive
► True
► False
Question No: 29 ( Marks: 1 ) - Please choose one
The critical section problem can be solved by the following except
► Software based solution
► Firmware based solution
► Operating system based solution
► Hardware based solution
Question No: 30 ( Marks: 1 ) - Please choose one
The bottom layer in the layered approach of Operating System is-----------
► User interface
► Hardware
► Kernel
► None of the given options
Question No: 31 ( Marks: 2 )
Under what conditions can you use the Wait-for graph to detect deadlock?
ANS:
We use wait-for graph in a condition if all the resources have only a single instance, then we use deadlock detection algorithm that uses a variant of the resource allocation graph.
Question No: 32 ( Marks: 2 )
List the four events that cause the execution of a piece of code in kernel.
Ans:
List the four events that cause the execution of a piece of code in kernel:
1- Interrupt
2- Trap
3- System call
4- signal
Question No: 33 ( Marks: 2 )
What is basic logic in FIFO page replacement algorithm?
Ans:
A FIFO page replacement algorithm correlates with every page to know the time when that page was brought into memory. When a page becomes to be replaced, the oldest page is chosen. It is not necessary to record the time when the page was brought in. for this we can create a FIFO queue to hold all pages into memory. We simply replace the page at the head of the queue.
Question No: 34 ( Marks: 2 )
The problem with using an acyclic-graph structure is ensuring that there are no cycles. What is the solution?
Question No: 35 ( Marks: 3 )
What are the three different stages/times when the addresses can be bound to instructions and data?
Ans:
1- compile time
2- load time
3- execution time
Question No: 36 ( Marks: 3 )
What is Mounting? Name two types of mounting. Give your answer with respect to File System?
Question No: 37 ( Marks: 3 )
List down two major benefits of Virtual Memory
Ans:
1-Users would be able to write programs for an extremely lagre virtual address space which simplify the programming task.
2- less input and output needed to load or swap each user program into memory, so each user program would run faster.
Question No: 38 ( Marks: 3 )
Write three main responsibilities of an operating system?
Ans:
1- manage secondary storage devices
2- manage processes
3- allow a user to manage files and directories properly
Question No: 39 ( Marks: 5 )
Briefly explain the difference Least frequently used and Most Frequently Used algorithms with respect to Page Replacement techniques.
Ans:
Question No: 40 ( Marks: 5 )
Calculate the maximum no. of bits required for page number and no. of bits required for frames when there are 16 pages and 32 frames in the system?