CS604 Operating System Solved Paper
Midterm 2011
SPRING 2011 (12 MAY 2011)
CS604 - OPERATING SYSTEMS
Time: 60 min
M a r k s: 38
CS604 - Operating System - Question No: 1 ( M a r k s: 1 ) http://vuzs.net
Linux is a version of _______ operating system.
Select correct option:
► OS/2
► Windows
► Unix
► None of the above
CS604 - Operating System - Question No: 2 ( M a r k s: 1 ) http://vuzs.net
Current working directory can be accessed using --------- Command.
Select correct option:
►. (dot)
► # ( hash )
► / (slash)
► ~ (tilt)
CS604 - Operating System - Question No: 3 ( M a r k s: 1 ) http://vuzs.net
Mkfifo() is a _______.
Select correct option:
► System Call
► Command
► Directory
► None of Above
CS604 - Operating System - Question No: 4 ( M a r k s: 1 ) http://vuzs.net
-------- command gives a snapshot of the current processes.
Select correct option:
► ps
► top
► who
► ls
CS604 - Operating System - Question No: 5 ( M a r k s: 1 ) http://vuzs.net
Time interval when the I/O Devices are accessed is known as --------.
Select correct option:
► CPU Burst
► IO Burst
► Time Slice
► None of Above
CS604 - Operating System - Question No: 6 ( M a r k s: 1 ) http://vuzs.net
The process of switching from one process to another is called ---------------.
Select correct option:
► context switching
► scheduling
► quantum period
► latency
CS604 - Operating System - Question No: 7 ( M a r k s: 1 ) http://vuzs.net
__________ directory includes essential system boot files including the kernel image.
Select correct option:
► /bin
► /boot
► /dev
► /etc
CS604 - Operating System - Question No: 8 ( M a r k s: 1 ) http://vuzs.net
________ scheduling algorithm is sometimes called shortest remaining time first scheduling algorithm.
Select correct option:
► Non-preemptive SJF
► Priority Scheduling
► Preemptive Shortest Job First
► FCFS
CS604 - Operating System - Question No: 9 ( M a r k s: 1 ) http://vuzs.net
A semaphore that cause Busy-Waiting is termed as ___________.
Select correct option:
► Spinlock
► Monitor
► Critical region
► Critical section
CS604 - Operating System - Question No: 10 ( M a r k s: 1 ) http://vuzs.net
Progress and Bounded Waiting are some of the characteristics to solve the critical section problems.
Select correct option:
► True
► False
CS604 - Operating System - Question No: 11 ( M a r k s: 1 ) http://vuzs.net
In ---------addressing, the recipient is not required to name the sender.
Select correct option:
► Symmetric
► Asymmetric
► Both symmetric and asymmetric
► None of the given options
CS604 - Operating System - Question No: 12 ( M a r k s: 1 ) http://vuzs.net
The execution of critical sections must NOT be mutually exclusive
Select correct option:
► True
► False
CS604 - Operating System - Question No: 13 ( M a r k s: 1 ) http://vuzs.net
A program in execution is called a _______________.
Select correct option:
► Command
► Process
► Software
► Compiler
CS604 - Operating System - Question No: 14 ( M a r k s: 1 ) http://vuzs.net
The critical section problem can be solved by the following except
► Software based solution
► Firmware based solution
► Operating system based solution
► Hardware based solution
CS604 - Operating System - Question No: 15 ( M a r k s: 1 ) http://vuzs.net
The bottom layer in the layered approach of Operating System is-----------
Select correct option:
► User interface
► Hardware
► Kernel
► None of the given options
CS604 - Operating System - Question No: 16 ( M a r k s: 1 ) http://vuzs.net
The manual pages can be read in Linux using ____ command.
Select correct option:
► man
► wan
► desc
► help
CS604 - Operating System - Question No: 17 ( M a r k s: 2 )
What is Convoy Effect?
Ans: Convoy effect is the result of mechanism in which some one has to follow an order like the movement of a convoy. In FCFS, a process whether shorter or smaller has to follow a queue to be assigned to a CPU. T
CS604 - Operating System - Question No: 18 ( M a r k s: 2 )
What are the common data structures in Bakery Algorithm?
Ans: The common data structures are:
CS604 - OPERATING SYSTEMS
Time: 60 min
M a r k s: 38
CS604 - Operating System - Question No: 1 ( M a r k s: 1 ) http://vuzs.net
Linux is a version of _______ operating system.
Select correct option:
► OS/2
► Windows
► Unix
► None of the above
CS604 - Operating System - Question No: 2 ( M a r k s: 1 ) http://vuzs.net
Current working directory can be accessed using --------- Command.
Select correct option:
►. (dot)
► # ( hash )
► / (slash)
► ~ (tilt)
CS604 - Operating System - Question No: 3 ( M a r k s: 1 ) http://vuzs.net
Mkfifo() is a _______.
Select correct option:
► System Call
► Command
► Directory
► None of Above
CS604 - Operating System - Question No: 4 ( M a r k s: 1 ) http://vuzs.net
-------- command gives a snapshot of the current processes.
Select correct option:
► ps
► top
► who
► ls
CS604 - Operating System - Question No: 5 ( M a r k s: 1 ) http://vuzs.net
Time interval when the I/O Devices are accessed is known as --------.
Select correct option:
► CPU Burst
► IO Burst
► Time Slice
► None of Above
CS604 - Operating System - Question No: 6 ( M a r k s: 1 ) http://vuzs.net
The process of switching from one process to another is called ---------------.
Select correct option:
► context switching
► scheduling
► quantum period
► latency
CS604 - Operating System - Question No: 7 ( M a r k s: 1 ) http://vuzs.net
__________ directory includes essential system boot files including the kernel image.
Select correct option:
► /bin
► /boot
► /dev
► /etc
CS604 - Operating System - Question No: 8 ( M a r k s: 1 ) http://vuzs.net
________ scheduling algorithm is sometimes called shortest remaining time first scheduling algorithm.
Select correct option:
► Non-preemptive SJF
► Priority Scheduling
► Preemptive Shortest Job First
► FCFS
CS604 - Operating System - Question No: 9 ( M a r k s: 1 ) http://vuzs.net
A semaphore that cause Busy-Waiting is termed as ___________.
Select correct option:
► Spinlock
► Monitor
► Critical region
► Critical section
CS604 - Operating System - Question No: 10 ( M a r k s: 1 ) http://vuzs.net
Progress and Bounded Waiting are some of the characteristics to solve the critical section problems.
Select correct option:
► True
► False
CS604 - Operating System - Question No: 11 ( M a r k s: 1 ) http://vuzs.net
In ---------addressing, the recipient is not required to name the sender.
Select correct option:
► Symmetric
► Asymmetric
► Both symmetric and asymmetric
► None of the given options
CS604 - Operating System - Question No: 12 ( M a r k s: 1 ) http://vuzs.net
The execution of critical sections must NOT be mutually exclusive
Select correct option:
► True
► False
CS604 - Operating System - Question No: 13 ( M a r k s: 1 ) http://vuzs.net
A program in execution is called a _______________.
Select correct option:
► Command
► Process
► Software
► Compiler
CS604 - Operating System - Question No: 14 ( M a r k s: 1 ) http://vuzs.net
The critical section problem can be solved by the following except
► Software based solution
► Firmware based solution
► Operating system based solution
► Hardware based solution
CS604 - Operating System - Question No: 15 ( M a r k s: 1 ) http://vuzs.net
The bottom layer in the layered approach of Operating System is-----------
Select correct option:
► User interface
► Hardware
► Kernel
► None of the given options
CS604 - Operating System - Question No: 16 ( M a r k s: 1 ) http://vuzs.net
The manual pages can be read in Linux using ____ command.
Select correct option:
► man
► wan
► desc
► help
CS604 - Operating System - Question No: 17 ( M a r k s: 2 )
What is Convoy Effect?
Ans: Convoy effect is the result of mechanism in which some one has to follow an order like the movement of a convoy. In FCFS, a process whether shorter or smaller has to follow a queue to be assigned to a CPU. T
CS604 - Operating System - Question No: 18 ( M a r k s: 2 )
What are the common data structures in Bakery Algorithm?
Ans: The common data structures are:
boolean choosing [n];
int number[n];
CS604 - Operating System - Question No: 19 ( M a r k s: 2 )
How a pipe can be created?
Ans: The pipe() system call creates a pipe and returns two file descriptors, one for
reading and second for writing. The files associated with these
file descriptors are streams and are both opened for reading and writing. Naturally, to use
such a channel properly, one needs to form some kind of protocol in which data is sent
over the pipe.
CS604 - Operating System - Question No: 20 ( M a r k s: 3 )
Define Progress and Bounded Waiting.
Ans: 2. Progress
CS604 - Operating System - Question No: 20 ( M a r k s: 3 )
Define Progress and Bounded Waiting.
Ans: 2. Progress
If no process is executing in its critical section and some processes wish to enter their
critical sections, then only those processes that are not executing in their remainder
section can participate in the decision on which will enter its critical section next, and
this selection cannot be postponed indefinitely.
3. Bounded Waiting
There exists a bound on the number of times that other processes are allowed to enter
their critical sections after a process has made a request to enter its critical section and
before that request is granted.
CS604 - Operating System - Question No: 21 ( M a r k s: 3 )
What is Starvation and how it occures
Ans: A major problem with priority- scheduling algorithms is indefinite blocking (or
starvation). A process that is ready to run but lacking the CPU can be considered
blocked-waiting for the CPU.
CS604 - Operating System - Question No: 22 ( M a r k s: 5 )
What are the advantages of Round Robin Scheduling Algorithm?
CS604 - Operating System - Question No: 23 ( M a r k s: 5 )
Analyze the following algorithm to solve the critical section problem and explain whether it satisfies the Mutual Exclusion Characteristic
Flag[i] = True;
Turn = j;
do{
while(Flag[j] = True && turn==j);
critical section
Flag[i] = False;
remainder section
} While(1)
CS604 - Operating System - Question No: 22 ( M a r k s: 5 )
What are the advantages of Round Robin Scheduling Algorithm?
CS604 - Operating System - Question No: 23 ( M a r k s: 5 )
Analyze the following algorithm to solve the critical section problem and explain whether it satisfies the Mutual Exclusion Characteristic
Flag[i] = True;
Turn = j;
do{
while(Flag[j] = True && turn==j);
critical section
Flag[i] = False;
remainder section
} While(1)
Ans: To prove mutual exclusion, note that Pi enters its critical section only if either
flag[j]=false or turn=i. Also, if both processes were executing in their critical sections at
the same time, then flag[0]= = flag[1]= = true. These two observations suggest that P0 and
P1 could not have found both conditions in the while statement true at the same time,
since the value of ‘turn’ can either be 0 or 1. Hence only one process say P0 must have
successfully exited the while statement. Hence mutual exclusion is preserved.
