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View Full Version : CS604 FinalTerm current solve paper spring July 2011



Vuhelper
07-11-2011, 08:26 PM
Question No: 1 ( Marks: 1 ) - Please choose one

A ---------------- (or an exception) is a software-generated interrupt caused either by an error (division by zero or invalid memory access) or by a user request for an operating system service.



► Interrupt



► Trap



► Signal



► Process



Question No: 2 ( Marks: 1 ) - Please choose one

Which register holds the smallest legal physical memory address for a process?





► Base register





► Limit register



► Status register

► None of the given options



Question No: 3 ( Marks: 1 ) - Please choose one

The process of switching from one process to another is called -----------------





► context switching

► scheduling

► quantum period

► latency



Question No: 4 ( Marks: 1 ) - Please choose one

The --------------semaphore provides mutual exclusion for accesses to the buffer pool and is initialized to the value 1.



► mutex









► binary

► couting

► none of the given options



Question No: 5 ( Marks: 1 ) - Please choose one

Binary semaphores are those that have only two values---------



► 0 and n











► 0 and 0

► 0 and 1

► None of the given options



Question No: 6 ( Marks: 1 ) - Please choose one

Addresses generated relative to part of program, not to start of physical memory are



► Virtual

► Physical

► Relocatable







► Symbolic



Question No: 7 ( Marks: 1 ) - Please choose one

Object files and libraries are combined by a ------------- program to produce the executable binary



► Compiler











► Linker

► Text editor

► Loader



Question No: 8 ( Marks: 1 ) - Please choose one

Physical memory is broken down into fixed-sized blocks, called----------- and Logical memory is divided into blocks of the same size, called -----------





► Frames, pages









► Pages, Frames

► Frames, holes

► Holes, segments



Question No: 9 ( Marks: 1 ) - Please choose one

A page table needed for keeping track of pages of the page table is called --------------





► 2-level paging











► Page directory

► Page size

► Page table size





Question No: 10 ( Marks: 1 ) - Please choose one

The address generated by the CPU, after any indexing or other addressing-mode arithmetic, is called a --------address, and the address it gets translated to by the MMU is called a ---------address.











Virtual, physical



► Hexadecimal, Binary,

► Valid, invalid

► Physical, Virtual



Question No: 11 ( Marks: 1 ) - Please choose one

Each page is a power of -------- bytes long in paging scheme.



► 2











► 3

► 4

► 5



Question No: 12 ( Marks: 1 ) - Please choose one

_______ is a way to establish a connection between the file to be shared and the directory entries of the users who want to have aces to this file.





► Link







► Directory

► Common Group

► Access Permission



Question No: 13 ( Marks: 1 ) - Please choose one

When a _____link is created, a directory entry for the existing file is created



► Soft





None of the given options





► Hard

► Soft or Hard

► Soft or Hard



Question No: 14 ( Marks: 1 ) - Please choose one

The ___________ method requires each file to occupy a set of contiguous blocks on the disk.





► Contiguous Allocation









► Linked Allocation

► Indexed Allocation

► None of the given options



Question No: 15 ( Marks: 1 ) - Please choose one

Which part of the computer system helps in managing the file and memory management system?



► Operating System



► Device Drivers



► Application Software



► Hardware





Question No: 16 ( Marks: 1 ) - Please choose one

Which of the following is correct definition for wait operation?



► wait(S) {

while(S<=0)

;// no op

S--;

}



► wait(S) {

S++;

}



► wait(S) {

while(S>=0)

;// no op

S--;

}



► wait(S) {

S--;

}





Question No: 17 ( Marks: 1 ) - Please choose one

Wrong use of wait and signal operations (in context with semaphores) can cause _________ problem(s).



► Mutual Exclusion



► Deadlock



► Bounded Waiting



► All of the given options are correct





Question No: 18 ( Marks: 1 ) - Please choose one

If a system is not in a safe state, there can be no deadlocks.



► True



► False







Question No: 19 ( Marks: 1 ) - Please choose one

If a process continues to fault, replacing pages, for which it then faults and brings back in right away. This high paging activity is called ___________.

► paging

► thrashing

► page fault

► CPU utilization



Question No: 20 ( Marks: 1 ) - Please choose one

In _____________ page replace algorithm we will replace the page that has not been used for the longest period of time.

► counter based

► Least Frequently Used

► FIFO

► LRU



Question No: 21 ( Marks: 1 ) - Please choose one

Overlays are implemented by the _________________



► Operating system



► Programmer



► Kernel



► Shell





Question No: 22 ( Marks: 1 ) - Please choose one

An acyclic graph does not allow directories to have shared subdirectories and files.

► True

► False



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?