Introduction to Operating System MCQ
Introduction to OSWhat is operating system?
a) collection of programs that manages hardware resources
b) system service provider to the application programs
c) link to interface the hardware and application programs
d) all of the mentioned
Answer : d) all of the mentioned
To access the services of operating system, the interface is
provided by the ___________
a) System calls
b) API
c) Library
d) Assembly instructions
Answer : a) System calls
Which one of the following is not true?
a) kernel is the program that constitutes the central core
of the operating system
b) kernel is the first part of operating system to load into
memory during booting
c) kernel is made of various modules which can not be loaded
in running operating system
d) kernel remains in the memory during the entire computer
session
Answer : c) kernel is made of various modules which can not
be loaded in running operating system
Which one of the following error will be handle by the
operating system?
a) power failure
b) lack of paper in printer
c) connection failure in the network
d) all of the mentioned
Answer : d) all of the mentioned
What is the main function of the command interpreter?
a) to get and execute the next user-specified command
b) to provide the interface between the API and application
program
c) to handle the files in operating system
d) none of the mentioned
Answer : a) to get and execute the next user-specified
command
By operating system, the resource management can be done via
__________
a) time division multiplexing
b) space division multiplexing
c) time and space division multiplexing
d) none of the mentioned
Answer : c) time and space division multiplexing
If a process fails, most operating system write the error
information to a ______
a) log file
b) another running process
c) new file
d) none of the mentioned
Answer : a) log file
System Structure
Which facility dynamically adds probes to a running system,
both in user processes and in the kernel?
a) DTrace
b) DLocate
c) DMap
d) DAdd
Answer : a) DTrace
Which one of the following is not a real time operating
system?
a) VxWorks
b) Windows CE
c) RTLinux
d) Palm OS
Answer : d) Palm OS
The OS X has ____________
a) monolithic kernel
b) hybrid kernel
c) microkernel
d) monolithic kernel with modules
Answer : c) microkernel
The systems which allow only one process execution at a
time, are called __________
a) uniprogramming systems
b) uniprocessing systems
c) unitasking systems
d) none of the mentioned
Answer : b) uniprocessing systems
The systems which allow only one process execution at a
time, are called __________
a) uniprogramming systems
b) uniprocessing systems
c) unitasking systems
d) none of the mentioned
Answer : b) uniprocessing systems
In operating system, each process has its own __________
a) address space and global variables
b) open files
c) pending alarms, signals and signal handlers
d) all of the mentioned
Answer : d) all of the mentioned
In Unix, Which system call creates the new process?
a) fork
b) create
c) new
d) none of the
Answer : a) fork
Process Management
A process can be terminated due to __________
a) normal exit
b) fatal error
c) killed by another process
d) all of the mentioned
Answer : d) all of the mentioned
What is the ready state of a process?
a) when process is scheduled to run after some execution
b) when process is unable to run until some task has been
completed
c) when process is using the CPU
d) none of the mentioned
Answer : a) when process is scheduled to run after some
execution
What is interprocess communication?
a) communication within the process
b) communication between two process
c) communication between two threads of same process
d) none of the mentioned
Answer : b) communication between two process
A set of processes is deadlock if __________
a) each process is blocked and will remain so forever
b) each process is terminated
c) all processes are trying to kill each other
d) none of the mentioned
Answer : a) each process is blocked and will remain so
forever
A process stack does not contain __________
a) Function parameters
b) Local variables
c) Return addresses
d) PID of child process
Answer : d) PID of child process
Which system call returns the process identifier of a
terminated child?
a) wait
b) exit
c) fork
d) get
Answer : a) wait
The address of the next instruction to be executed by the
current process is provided by the __________
a) CPU registers
b) Program counter
c) Process stack
d) Pipe
Answer : b) Program counter
A Process Control Block(PCB) does not contain which of the
following?
a) Code
b) Stack
c) Bootstrap program
d) Data
Answer : c) Bootstrap program
The number of processes completed per unit time is known as
__________
a) Output
b) Throughput
c) Efficiency
d) Capacity 24.
Answer : b) Throughput
The state of a process is defined by __________
a) the final activity of the process
b) the activity just executed by the process
c) the activity to next be executed by the process
d) the current activity of the process
Answer : d) the current activity of the process
Which of the
following is not the state of a process?
a) New
b) Old
c) Waiting
d) Running
Answer : b) Old
What is a Process Control Block?
a) Process type variable
b) Data Structure
c) A secondary storage section
d) A Block in memory
Answer : b) Data Structure
The entry of all the PCBs of the current processes is in
__________
a) Process Register
b) Program Counter
c) Process Table
d) Process Unit
Answer : c) Process Table
What is the degree of multiprogramming?
a) the number of processes executed per unit time
b) the number of processes in the ready queue
c) the number of processes in the I/O queue
d) the number of processes in memory
Answer : d) the number of processes in memory
A single thread of control allows the process to perform
__________
a) only one task at a time
b) multiple tasks at a time
c) only two tasks at a time
d) all of the mentioned
Answer : a) only one task at a time
Process Synchronization
What is the objective of multiprogramming?
a) Have some process running at all times
b) Have multiple programs waiting in a queue ready to run
c) To minimize CPU utilization
d) None of the mentioned
Answer : a) Have some process running at all times
Which of the following do not belong to queues for
processes?
a) Job Queue
b) PCB queue
c) Device Queue
d) Ready Queue
Answer : b) PCB queue
When the process issues an I/O request __________
a) It is placed in an I/O queue
b) It is placed in a waiting queue
c) It is placed in the ready queue
d) It is placed in the Job queue
Answer : a) It is placed in an I/O queue
What will happen when a process terminates?
a) It is removed from all queues
b) It is removed from all, but the job queue
c) Its process control block is de-allocated
d) Its process control block is never de-allocated
Answer : a) It is removed from all queues
What is a long-term scheduler?
a) It selects which process has to be brought into the ready
queue
b) It selects which process has to be executed next and
allocates CPU
c) It selects which process to remove from memory by
swapping
d) None of the mentioned
Answer : a) It selects which process has to be brought into
the ready queue
If all processes I/O bound, the ready queue will almost
always be ______ and the Short term Scheduler will have a ______ to do.
a) full, little
b) full, lot
c) empty, little
d) empty, lot
Answer : c) empty, little
What is a medium-term scheduler?
a) It selects which process has to be brought into the ready
queue
b) It selects which process has to be executed next and
allocates CPU
c) It selects which process to remove from memory by
swapping
d) None of the mentioned
Answer : c) It selects which process to remove from memory
by swapping
What is a short-term scheduler?
a) It selects which process has to be brought into the ready
queue
b) It selects which process has to be executed next and
allocates CPU
c) It selects which process to remove from memory by
swapping
d) None of the mentioned
Answer : b) It selects which process has to be executed next
and allocates CPU
The primary distinction between the short term scheduler and
the long term scheduler is __________
a) The length of their queues
b) The type of processes they schedule
c) The frequency of their execution
d) None of the mentioned
Answer : c) The frequency of their execution
The only state transition that is initiated by the user
process itself is __________
a) block
b) wakeup
c) dispatch
d) none of the mentioned
Answer : a) block
In a time-sharing operating system, when the time slot given
to a process is completed, the process goes from the running state to the
__________
a) Blocked state
b) Ready state
c) Suspended state
d) Terminated state
Answer : b) Ready state
In a multiprogramming environment __________
a) the processor executes more than one process at a time
b) the programs are developed by more than one person
c) more than one process resides in the memory
d) a single user can execute many programs at the same time
Answer : c) more than one process resides in the memory
Suppose that a process is in “Blocked” state waiting for
some I/O service. When the service is completed, it goes to the __________
a) Running state
b) Ready state
c) Suspended state
d) Terminated state
Answer : b) Ready state
The context of a process in the PCB of a process does not
contain __________
a) the value of the CPU registers
b) the process state
c) memory-management information
d) context switch time
Answer : d) context switch time
Which of the following need not necessarily be saved on a
context switch between processes?
a) General purpose registers
b) Translation lookaside buffer
c) Program counter
d) All of the mentioned
Answer : b) Translation lookaside buffer
Which of the following does not interrupt a running process?
a) A device
b) Timer
c) Scheduler process
d) Power failure
Answer : c) Scheduler process
Which process can be affected by other processes executing
in the system?
a) cooperating process
b) child process
c) parent process
d) init process
Answer : a) cooperating process
When several processes access the same data concurrently and
the outcome of the execution depends on the particular order in which the
access takes place, is called?
a) dynamic condition
b) race condition
c) essential condition
d) critical condition
Answer : b) race condition
If a process is executing in its critical section, then no
other processes can be executing in their critical section. This condition is
called?
a) mutual exclusion
b) critical exclusion
c) synchronous exclusion
d) asynchronous exclusion
Answer : a) mutual exclusion
Which one of the following is a synchronization tool?
a) thread
b) pipe
c) semaphore
d) socket
Answer : c) semaphore
A semaphore is a shared integer variable __________
a) that can not drop below zero
b) that can not be more than zero
c) that can not drop below one
d) that can not be more than one
Answer : a) that can not drop below zero
Mutual exclusion can be provided by the __________
a) mutex locks b) binary semaphores
c) both mutex locks and binary semaphores
d) none of the mentioned
Answer : c) both mutex locks and binary semaphores
When high priority task is indirectly preempted by medium
priority task effectively inverting the relative priority of the two tasks, the
scenario is called __________
a) priority inversion
b) priority removal
c) priority exchange
d) priority modification
Answer : a) priority inversion
Process synchronization can be done on __________
a) hardware level
b) software level
c) both hardware and software level
d) none of the mentioned
Answer : c) both hardware and software level
A monitor is a module that encapsulates __________
a) shared data structures
b) procedures that operate on shared data structure
c) synchronization between concurrent procedure invocation
d) all of the mentioned
Answer : d) all of the mentioned
To enable a process to wait within the monitor __________
a) a condition variable must be declared as condition
b) condition variables must be used as Boolean objects
c) semaphore must be used
d) all of the mentioned
Answer : a) a condition variable must be declared as
condition
Restricting the child process to a subset of the parent’s
resources prevents any process from __________
a) overloading the system by using a lot of secondary
storage
b) under-loading the system by very less CPU utilization
c) overloading the system by creating a lot of sub-processes
d) crashing the system by utilizing multiple resources
Answer : c) overloading the system by creating a lot of
sub-processes
A parent process calling _____ system call will be suspended
until children processes terminate.
a) wait
b) fork
c) exit
d) exec
Answer : a) wait
Cascading termination refers to termination of all child
processes before the parent terminates ______
a) Normally
b) Abnormally
c) Normally or abnormally
d) None of the mentioned
Answer : a) Normally
With _____________ only one process can execute at a time;
meanwhile all other process are waiting for the processor. With ______________
more than one process can be running simultaneously each on a different
processor.
a) Multiprocessing, Multiprogramming
b) Multiprogramming, Uniprocessing
c) Multiprogramming, Multiprocessing
d) Uniprogramming, Multiprocessing
Answer : d) Uniprogramming, Multiprocessing
In UNIX, each process is identified by its __________
a) Process Control Block
b) Device Queue
c) Process Identifier
d) None of the mentioned
Answer : c) Process Identifier
In UNIX, the return value for the fork system call is _____
for the child process and _____ for the parent process.
a) A Negative integer, Zero
b) Zero, A Negative integer
c) Zero, A nonzero integer
d) A nonzero integer, Zero
Answer : c) Zero, A nonzero integer
The child process can __________
a) be a duplicate of the parent process
b) never be a duplicate of the parent process
c) cannot have another program loaded into it
d) never have another program loaded into it
Answer : a) be a duplicate of the parent process
The child process completes execution, but the parent keeps
executing, then the child process is known as __________
a) Orphan
b) Zombie
c) Body
d) Dead
Answer : b) Zombie
What is Inter process communication?
a) allows processes to communicate and synchronize their
actions when using the same address space
b) allows processes to communicate and synchronize their
actions without using the same address space
c) allows the processes to only synchronize their actions
without communication
d) none of the mentioned
Answer : b) allows processes to communicate and synchronize
their actions without using the same address space
Message passing system allows processes to __________
a) communicate with one another without resorting to shared
data
b) communicate with one another by resorting to shared data
c) share data
d) name the recipient or sender of the message
Answer : a) communicate with one another without resorting
to shared data
Which of the following two operations are provided by the
IPC facility?
a) write & delete message
b) delete & receive message
c) send & delete message
d) receive & send message
Answer : d) receive & send message
Messages sent by a process __________
a) have to be of a fixed size
b) have to be a variable size
c) can be fixed or variable sized
d) None of the mentioned
Answer : c) can be fixed or variable sized
The link between two processes P and Q to send and receive
messages is called __________
a) communication link
b) message-passing link
c) synchronization link
d) all of the mentioned
Answer : a) communication link
Which of the following are TRUE for direct communication?
a) A communication link can be associated with N number of
process(N = max. number of processes supported by system)
b) A communication link can be associated with exactly two
processes
c) Exactly N/2 links exist between each pair of processes(N
= max. number of processes supported by system)
d) Exactly two link exists between each pair of processes
Answer : b) A communication link can be associated with
exactly two processes
In indirect communication between processes P and Q
__________
a) there is another process R to handle and pass on the
messages between P and Q
b) there is another machine between the two processes to
help communication
c) there is a mailbox to help communication between P and Q
d) none of the mentioned
Answer : c) there is a mailbox to help communication between
P and Q
In the non blocking send __________
a) the sending process keeps sending until the message is
received
b) the sending process sends the message and resumes
operation
c) the sending process keeps sending until it receives a
message
d) none of the mentioned
Answer : b) the sending process sends the message and
resumes operation
In the Zero capacity queue __________
a) the queue can store at least one message
b) the sender blocks until the receiver receives the message
c) the sender keeps sending and the messages don’t wait in
the queue
d) none of the mentioned
Answer : b) the sender blocks until the receiver receives
the message
The Zero Capacity queue __________
a) is referred to as a message system with buffering
b) is referred to as a message system with no buffering
c) is referred to as a link d) none of the mentioned
Answer : b) is referred to as a message system with no
buffering
Bounded capacity and Unbounded capacity queues are referred
to as __________
a) Programmed buffering
b) Automatic buffering
c) User defined buffering
d) No buffering
Answer : b) Automatic buffering
Remote Procedure Calls are used ____________
a) for communication between two processes remotely different
from each other on the same system
b) for communication between two processes on the same
system
c) for communication between two processes on separate
systems
d) none of the mentioned
Answer : c) for communication between two processes on
separate systems
To differentiate the many network services a system supports
______ are used.
a) Variables
b) Sockets
c) Ports
d) Service names
Answer : c) Ports
RPC provides a(an) _____ on the client side, a separate one
for each remote procedure.
a) stub
b) identifier
c) name
d) process identifier
Answer : a) stub
What is stub?
a) transmits the message to the server where the server side
stub receives the message and invokes procedure on the server side
b) packs the parameters into a form transmittable over the
network
c) locates the port on the server
d) all of the mentioned
Answer : d) all of the mentioned
To resolve the problem of data representation on different
systems RPCs define _____________
a) machine dependent representation of data
b) machine representation of data
c) machine-independent representation of data
d) none of the mentioned
Answer : c) machine-independent representation of data
What is the full form of RMI?
a) Remote Memory Installation
b) Remote Memory Invocation
c) Remote Method Installation
d) Remote Method Invocation
Answer : d) Remote Method Invocation
The remote method invocation __________
a) allows a process to invoke memory on a remote object
b) allows a thread to invoke a method on a remote object
c) allows a thread to invoke memory on a remote object
d) allows a process to invoke a method on a remote object
Answer : b) allows a thread to invoke a method on a remote
object
A process that is based on IPC mechanism which executes on
different systems and can communicate with other processes using message based
communication, is called ________
a) Local Procedure Call
b) Inter Process Communication
c) Remote Procedure Call
d) Remote Machine Invocation
Answer : c) Remote Procedure Call
The initial program that is run when the computer is powered
up is called __________
a) boot program
b) bootloader
c) initializer
d) bootstrap program
Answer : d) bootstrap program
How does the software trigger an interrupt?
a) Sending signals to CPU through bus
b) Executing a
special operation called system call
c) Executing a special program called system program
d) Executing a special program called interrupt trigger
program
Answer : b) Executing a special operation called system call
CPU Scheduling
What is a trap/exception?
a) hardware generated interrupt caused by an error
b) software generated interrupt caused by an error
c) user generated interrupt caused by an error
d) none of the mentioned
Answer : b) software generated interrupt caused by an error
What is an ISR?
a) Information Service Request
b) Interrupt Service Request
c) Interrupt Service Routine
d) Information Service Routine
Answer : c) Interrupt Service Routine
What is an interrupt vector?
a) It is an address that is indexed to an interrupt handler
b) It is a unique device number that is indexed by an
address
c) It is a unique identity given to an interrupt
d) None of the mentioned
Answer : a) It is an address that is indexed to an interrupt
handler
DMA is used for __________
a) High speed devices(disks and communications network)
b) Low speed devices
c) Utilizing CPU cycles
d) All of the mentioned
Answer : a) High speed devices(disks and communications
network)
In a memory mapped input/output __________
a) the CPU uses polling to watch the control bit constantly,
looping to see if a device is ready
b) the CPU writes one data byte to the data register and
sets a bit in control register to show that a byte is available
c) the CPU receives an interrupt when the device is ready
for the next byte
d) the CPU runs a user written code and does accordingly
Answer : b) the CPU writes one data byte to the data
register and sets a bit in control register to show that a byte is available
In a programmed input/output(PIO) __________
a) the CPU uses polling to watch the control bit constantly,
looping to see if a device is ready
b) the CPU writes one data byte to the data register and
sets a bit in control register to show that a byte is available
c) the CPU receives an interrupt when the device is ready
for the next byte
d) the CPU runs a user written code and does accordingly
Answer : a) the CPU uses polling to watch the control bit
constantly, looping to see if a device is ready
In an interrupt driven input/output __________
a) the CPU uses polling to watch the control bit constantly,
looping to see if a device is ready
b) the CPU writes one data byte to the data register and
sets a bit in control register to show that a byte is available
c) the CPU receives an interrupt when the device is ready
for the next byte
d) the CPU runs a user written code and does accordingly
Answer : c) the CPU receives an interrupt when the device is
ready for the next byte
In the layered approach of Operating Systems __________
a) Bottom Layer(0) is the User interface
b) Highest Layer(N) is the User interface
c) Bottom Layer(N) is the hardware
d) Highest Layer(N) is the hardware
Answer : b) Highest Layer(N) is the User interface
How does the Hardware trigger an interrupt?
a) Sending signals to CPU through a system bus
b) Executing a special program called interrupt program
c) Executing a special program called system program
d) Executing a special operation called system call
Answer : a) Sending signals to CPU through a system bus
Which operation is performed by an interrupt handler?
a) Saving the current state of the system
b) Loading the interrupt handling code and executing it
c) Once done handling, bringing back the system to the
original state it was before the interrupt occurred
d) All of the mentioned
Answer : d) All of the mentioned
Which module gives control of the CPU to the process
selected by the short-term scheduler?
a) dispatcher
b) interrupt
c) scheduler
d) none of the mentioned
Answer : a) dispatcher
The processes that are residing in main memory and are ready
and waiting to execute are kept on a list called _____________
a) job queue
b) ready queue
c) execution queue
d) process queue
Answer : b) ready queue
The interval from the time of submission of a process to the
time of completion is termed as ____________
a) waiting time
b) turnaround time
c) response time
d) throughput
Answer : b) turnaround time
Which scheduling algorithm allocates the CPU first to the
process that requests the CPU first?
a) first-come, first-served scheduling
b) shortest job scheduling
c) priority scheduling
d) none of the mentioned
Answer : a) first-come, first-served scheduling
In priority scheduling algorithm ____________
a) CPU is allocated to the process with highest priority
b) CPU is allocated to the process with lowest priority
c) Equal priority processes can not be scheduled
d) None of the mentioned
Answer : a) CPU is allocated to the process with highest
priority
In priority scheduling algorithm, when a process arrives at
the ready queue, its priority is compared with the priority of ____________
a) all process
b) currently running process
c) parent process
d) init process
Answer : b) currently running process
Which algorithm is defined in Time quantum?
a) shortest job scheduling algorithm
b) round robin scheduling algorithm
c) priority scheduling algorithm
d) multilevel queue scheduling algorithm
Answer : b) round robin scheduling algorithm
Process are classified into different groups in ____________
a) shortest job scheduling algorithm
b) round robin scheduling algorithm
c) priority scheduling algorithm
d) multilevel queue scheduling algorithm
Answer : d) multilevel queue scheduling algorithm
In multilevel feedback scheduling algorithm ____________
a) a process can move to a different classified ready queue
b) classification of ready queue is permanent
c) processes are not classified into groups
d) none of the mentioned
Answer : a) a process can move to a different classified
ready queue
Which one of the following can not be scheduled by the
kernel?
a) kernel level thread
b) user level thread
c) process
d) none of the mentioned
Answer : b) user level thread
CPU scheduling is the basis of ___________
a) multiprocessor systems
b) multiprogramming operating systems
c) larger memory sized systems
d) none of the mentioned
Answer : b) multiprogramming operating systems
With multiprogramming ______ is used productively.
a) time
b) space
c) money
d) all of the mentioned
Answer : a) time
What are the two steps of a process execution?
a) I/O & OS Burst
b) CPU & I/O Burst
c) Memory & I/O Burst
d) OS & Memory Burst
Answer : b) CPU & I/O Burst
An I/O bound program will typically have ____________
a) a few very short CPU bursts
b) many very short I/O bursts
c) many very short CPU bursts
d) a few very short I/O bursts
Answer : c) many very short CPU bursts
A process is selected from the ______ queue by the ________
scheduler, to be executed.
a) blocked, short term
b) wait, long term
c) ready, short term
d) ready, long term
Answer : c) ready, short term
In the following cases non – preemptive scheduling occurs?
a) When a process switches from the running state to the
ready state
b) When a process goes from the running state to the waiting
state
c) When a process switches from the waiting state to the
ready state
d) All of the mentioned
Answer : b) When a process goes from the running state to
the waiting state
The switching of the CPU from one process or thread to
another is called ____________
a) process switch
b) task switch
c) context
d) all of the mentioned
Answer : d) all of the mentioned
What is Dispatch latency?
a) the speed of dispatching a process from running to the
ready state
b) the time of dispatching a process from running to ready
state and keeping the CPU idle
c) the time to stop one process and start running another
one
d) none of the mentioned
Answer : c) the time to stop one process and start running
another one
Scheduling is done so as to ____________
a) increase CPU utilization
b) decrease CPU utilization
c) keep the CPU more idle
d) none of the mentioned
Answer : a) increase CPU utilization
Scheduling is done so as to ____________
a) increase the throughput
b) decrease the throughput
c) increase the duration of a specific amount of work
d) none of the mentioned
Answer : a) increase the throughput
What is Turnaround time?
a) the total waiting time for a process to finish execution
b) the total time spent in the ready queue
c) the total time spent in the running queue
d) the total time from the completion till the submission of
a process
Answer : d) the total time from the completion till the
submission of a process
Scheduling is done so as to ____________
a) increase the turnaround time
b) decrease the turnaround time
c) keep the turnaround time same
d) there is no relation between scheduling and turnaround
time
Answer : b) decrease the turnaround time
What is Waiting time?
a) the total time in the blocked and waiting queues
b) the total time spent in the ready queue
c) the total time spent in the running queue
d) the total time from the completion till the submission of
a process
Answer : b) the total time spent in the ready queue
Scheduling is done so as to ____________
a) increase the waiting time
b) keep the waiting time the same
c) decrease the waiting time
d) none of the mentioned
Answer : c) decrease the waiting time
What is Response time?
a) the total time taken from the submission time till the
completion time
b) the total time taken from the submission time till the
first response is produced
c) the total time taken from submission time till the
response is output
d) none of the mentioned
Answer : b) the total time taken from the submission time
till the first response is produced
Round robin scheduling falls under the category of
____________
a) Non-preemptive scheduling
b) Preemptive scheduling
c) All of the mentioned
d) None of the mentioned
Answer : b) Preemptive scheduling
With round robin scheduling algorithm in a time shared
system ____________
a) using very large time slices converts it into First come
First served scheduling algorithm
b) using very small time slices converts it into First come
First served scheduling algorithm
c) using extremely small time slices increases performance
d) using very small time slices converts it into Shortest
Job First algorithm
Answer : a) using very large time slices converts it into
First come First served scheduling algorithm
The portion of the process scheduler in an operating system
that dispatches processes is concerned with ____________
a) assigning ready processes to CPU
b) assigning ready processes to waiting queue
c) assigning running processes to blocked queue
d) all of the mentioned
Answer : a) assigning ready processes to CPU
Complex scheduling algorithms ____________
a) are very appropriate for very large computers
b) use minimal resources c) use many resources
d) all of the mentioned
Answer : a) are very appropriate for very large computers
What is FIFO algorithm?
a) first executes the job that came in last in the queue
b) first executes the job that came in first in the queue
c) first executes the job that needs minimal processor
d) first executes the job that has maximum processor needs
Answer : b)first executes the job that came in first in the
queue
The strategy of making processes that are logically runnable
to be temporarily suspended is called ____________
a) Non preemptive scheduling
b) Preemptive scheduling
c) Shortest job first
d) First come First served
Answer : b) Preemptive scheduling
What is Scheduling?
a) allowing a job to use the processor
b) making proper use of processor
c) all of the mentioned
d) none of the mentioned
Answer : a) allowing a job to use the processor
There are 10 different processes running on a workstation.
Idle processes are waiting for an input event in the input queue. Busy
processes are scheduled with the Round-Robin time sharing method. Which out of
the following quantum times is the best value for small response times, if the
processes have a short runtime, e.g. less than 10ms?
a) tQ = 15ms
b) tQ = 40ms
c) tQ = 45ms
d) tQ = 50ms
Answer : a) tQ = 15ms
Orders are processed in the sequence they arrive if _______
rule sequences the jobs.
a) earliest due date
b) slack time remaining
c) first come, first served
d) critical ratio
Answer : c) first come, first served
Which of the following algorithms tends to minimize the
process flow time?
a) First come First served
b) Shortest Job First
c) Earliest Deadline First
d) Longest Job First
Answer : b) Shortest Job First
Under multiprogramming, turnaround time for short jobs is
usually ________ and that for long jobs is slightly ___________
a) Lengthened; Shortened
b) Shortened; Lengthened
c) Shortened; Shortened
d) Shortened; Unchanged
Answer : b) Shortened; Lengthened
Which of the following statements are true? (GATE 2010)
I. Shortest remaining time first scheduling may cause
starvation
II. Preemptive scheduling may cause starvation
III. Round robin is better than FCFS in terms of response
time
a) I only
b) I and III only
c) II and III only
d) I, II and III
Answer : d) I, II and III
Which is the most optimal scheduling algorithm?
a) FCFS – First come First served
b) SJF – Shortest Job First
c) RR – Round Robin
d) None of the mentioned
Answer : b) SJF – Shortest Job First
The real difficulty with SJF in short term scheduling is
____________
a) it is too good an algorithm
b) knowing the length of the next CPU request
c) it is too complex to understand
d) none of the mentioned
Answer : b) knowing the length of the next CPU request
The FCFS algorithm is particularly troublesome for
____________
a) time sharing systems
b) multiprogramming systems
c) multiprocessor systems
d) operating systems
Answer : b) multiprogramming systems
Consider the following set of processes, the length of the
CPU burst time given in milliseconds. Process Burst time P1 6 P2 8 P3 7 P4 3
Assuming the above process being scheduled with the SJF scheduling algorithm.
a) The waiting time for process P1 is 3ms
b) The waiting time for process P1 is 0ms
c) The waiting time for process P1 is 16ms
d) The waiting time for process P1 is 9ms
Answer : a) The waiting time for process P1 is 3ms
Preemptive Shortest Job First scheduling is sometimes called
____________
a) Fast SJF scheduling
b) EDF scheduling – Earliest Deadline First
c) HRRN scheduling – Highest Response Ratio Next
d) SRTN scheduling – Shortest Remaining Time Next
Answer : d) SRTN scheduling – Shortest Remaining Time Next
An SJF algorithm is simply a priority algorithm where the
priority is ____________
a) the predicted next CPU burst
b) the inverse of the predicted next CPU burst
c) the current CPU burst
d) anything the user wants
Answer : a) the predicted next CPU burst
Choose one of the disadvantages of the priority scheduling
algorithm?
a) it schedules in a very complex manner
b) its scheduling takes up a lot of time
c) it can lead to some low priority process waiting
indefinitely for the CPU
d) none of the mentioned
Answer : c) it can lead to some low priority process waiting
indefinitely for the CPU
What is ‘Aging’?
a) keeping track of cache contents
b) keeping track of what pages are currently residing in
memory
c) keeping track of how many times a given page is
referenced
d) increasing the priority of jobs to ensure termination in
a finite time
Answer : d) increasing the priority of jobs to ensure
termination in a finite time
A solution to the problem of indefinite blockage of low –
priority processes is ____________
a) Starvation
b) Wait queue
c) Ready queue
d) Aging
Answer : d) Aging
Which of the following statements are true? (GATE 2010)
i) Shortest remaining time first scheduling may cause
starvation
ii) Preemptive scheduling may cause starvation
iii) Round robin is better than FCFS in terms of response
time
a) i only
b) i and iii
only c) ii and iii only
d) i, ii and iii
Answer : d) i, ii and iii
Which of the following scheduling algorithms gives minimum
average waiting time?
a) FCFS
b) SJF
c) Round – robin
d) Priority
Answer : b) SJF
Concurrent access to shared data may result in ____________
a) data consistency
b) data insecurity
c) data inconsistency
d) none of the mentioned
Answer : c) data inconsistency
A situation where several processes access and manipulate
the same data concurrently and the outcome of the execution depends on the
particular order in which access takes place is called ____________
a) data consistency
b) race condition
c) aging
d) starvation
Answer : b) race condition
The segment of code in which the process may change common
variables, update tables, write into files is known as ____________
a) program
b) critical section
c) non – critical section
d) synchronizing
Answer : d) synchronizing
Which of the following conditions must be satisfied to solve
the critical section problem? a) Mutual Exclusion
b) Progress
c) Bounded Waiting
d) All of the mentioned
Answer : d) All of the mentioned
Mutual exclusion implies that ____________
a) if a process is executing in its critical section, then
no other process must be executing in their critical sections
b) if a process is executing in its critical section, then
other processes must be executing in their critical sections
c) if a process is executing in its critical section, then
all the resources of the system must be blocked until it finishes execution
d) none of the mentioned
Answer : a) if a process is executing in its critical
section, then no other process must be executing in their critical sections
Bounded waiting implies that there exists a bound on the
number of times a process is allowed to enter its critical section ____________
a) after a process has made a request to enter its critical
section and before the request is granted
b) when another process is in its critical section
c) before a process has made a request to enter its critical
section
d) none of the mentioned
Answer : a) after a process has made a request to enter its
critical section and before the request is granted
A minimum of _____
variable(s) is/are required to be shared between processes to solve the
critical section problem.
a) one
b) two
c) three
d) four
Answer : b) two
IO System
In the bakery algorithm to solve the critical section
problem ____________
a) each process is put into a queue and picked up in an
ordered manner
b) each process receives a number (may or may not be unique)
and the one with the lowest number is served next
c) each process gets a unique number and the one with the
highest number is served next
d) each process gets a unique number and the one with the
lowest number is served next
Answer : b) each process receives a number (may or may not
be unique) and the one with the lowest number is served next
An un-interruptible unit is known as ____________
a) single
b) atomic
c) static
d) none of the mentioned
Answer : b) atomic
Test And Set instruction is executed ____________
a) after a particular process
b) periodically
c) atomically
d) none of the mentioned
Answer : c) atomically
Semaphore is a/an _______ to solve the critical section
problem.
a) hardware for a system
b) special program for a system
c) integer variable
d) none of the mentioned
Answer : c) integer variable
What are the two atomic operations permissible on
semaphores?
a) wait
b) stop
c) hold
d) none of the mentioned
Answer : a) wait
What are Spinlocks?
a) CPU cycles wasting locks over critical sections of
programs
b) Locks that avoid time wastage in context switches
c) Locks that work better on multiprocessor systems
d) All of the mentioned
Answer : d) All of the mentioned
What is the main disadvantage of spinlocks?
a) they are not sufficient for many process
b) they require busy waiting
c) they are
unreliable sometimes
d) they are too complex for programmers
Answer : b) they require busy waiting
The wait operation of the semaphore basically works on the
basic _______ system call.
a) stop()
b) block()
c) hold()
d) wait()
Answer : b) block()
The signal operation of the semaphore basically works on the
basic _______ system call.
a) continue()
b) wakeup()
c) getup()
d) start()
Answer : b) wakeup()
If the semaphore value is negative ____________
a) its magnitude is the number of processes waiting on that
semaphore
b) it is invalid
c) no operation can be further performed on it until the
signal operation is performed on it
d) none of the mentioned
Answer : a) its magnitude is the number of processes waiting
on that semaphore
The code that changes the value of the semaphore is
____________
a) remainder section code
b) non – critical section code
c) critical section code
d) none of the mentioned
Answer : c) critical section code
What will happen if a non-recursive mutex is locked more
than once?
a) Starvation
b) Deadlock
c) Aging
d) Signaling
Answer : d) Signaling
What is a semaphore?
a) is a binary mutex
b) must be accessed from only one process
c) can be accessed from multiple processes
d) none of the mentioned
Answer : c) can be accessed from multiple processes
What are the two kinds of semaphores?
a) mutex & counting
b) binary & counting
c) counting & decimal
d) decimal & binary
Answer : b) binary & counting
What is a mutex?
a) is a binary mutex
b) must be accessed from only one process
c) can be accessed from multiple processes
d) none of the mentioned
Answer : b) must be accessed from only one process
At a particular time of computation the value of a counting
semaphore is 7.Then 20 P operations and 15 V operations were completed on this
semaphore. The resulting value of the semaphore is? (GATE 1987) a) 42
b) 2
c) 7
d) 12
Answer : b) 2
A binary semaphore is a semaphore with integer values
____________
a) 1
b) -1
c) 0.8
d) 0.5
Answer : a) 1
Semaphores are mostly used to implement ____________
a) System calls
b) IPC mechanisms
c) System protection
d) None of the mentioned
Answer : b) IPC mechanisms
Spinlocks are intended to provide __________ only.
a) Mutual Exclusion
b) Bounded Waiting
c) Aging
d) Progress
Answer : b) Bounded Waiting
The bounded buffer problem is also known as ____________
a) Readers – Writers problem
b) Dining – Philosophers problem
c) Producer – Consumer problem
d) None of the mentioned
Answer : c) Producer – Consumer problem
In the bounded buffer problem, there are the empty and full
semaphores that ____________
a) count the number of empty and full buffers
b) count the number of empty and full memory spaces
c) count the number of empty and full queues
d) none of the mentioned Unit : Memory Management
Answer : a) count the number of empty and full buffers
In the bounded buffer problem ____________
a) there is only one buffer
b) there are n buffers ( n being greater than one but
finite)
c) there are infinite buffers
d) the buffer size is bounded
Answer : b) there are n buffers ( n being greater than one
but finite)
To ensure difficulties do not arise in the readers – writers
problem _______ are given exclusive access to the shared object.
a) readers
b) writers
c) readers and writers
d) none of the mentioned
Answer : b) writers
The dining – philosophers problem will occur in case of
____________
a) 5 philosophers and 5 chopsticks
b) 4 philosophers and 5 chopsticks
c) 3 philosophers and 5 chopsticks
d) 6 philosophers and 5 chopsticks
Answer : a) 5 philosophers and 5 chopsticks
A deadlock free solution to the dining philosophers problem
____________
a) necessarily eliminates the possibility of starvation
b) does not necessarily eliminate the possibility of
starvation
c) eliminates any possibility of any kind of problem further
d) none of the mentioned
Answer : b) does not necessarily eliminate the possibility
of starvation
A monitor is a type of ____________
a) semaphore
b) low level synchronization construct
c) high level synchronization construct
d) none of the mentioned
Answer : c) high level synchronization construct
A monitor is characterized by ____________
a) a set of programmer defined operators
b) an identifier
c) the number of variables in it
d) all of the mentioned
Answer : a) a set of programmer defined operators
File System
A procedure defined within a ________ can access only those
variables declared locally within the _______ and its formal parameters.
a) process, semaphore
b) process, monitor
c) semaphore, semaphore
d) monitor, monitor
Answer : d) monitor, monitor
The monitor construct ensures that ____________
a) only one process can be active at a time within the
monitor
b) n number of processes can be active at a time within the
monitor (n being greater than 1)
c) the queue has only one process in it at a time
d) all of the mentioned
Answer : a) only one process can be active at a time within
the monitor
What are the operations that can be invoked on a condition
variable?
a) wait & signal
b) hold & wait
c) signal & hold
d) continue & signal
Answer : a) wait & signal
Which is the process of invoking the wait operation?
a) suspended until another process invokes the signal
operation
b) waiting for another process to complete before it can
itself call the signal operation
c) stopped until the next process in the queue finishes
execution
d) none of the mentioned
Answer : a) suspended until another process invokes the
signal operation
If no process is suspended, the signal operation
____________
a) puts the system into a deadlock state
b) suspends some default process execution
c) nothing happens
d) the output is unpredictable
Answer : c) nothing happens
A collection of instructions that performs a single logical
function is called ____________
a) transaction
b) operation
c) function
d) all of the mentioned
Answer : a) transaction
A terminated
transaction that has completed its execution successfully is ____________
otherwise it is __________
a) committed, destroyed
b) aborted, destroyed
c) committed, aborted
d) none of the mentioned
Answer : c) committed, aborted
The state of the data accessed by an aborted transaction
must be restored to what it was just before the transaction started executing.
This restoration is known as ________ of transaction.
a) safety
b) protection
c) roll – back
d) revert – back
Answer : c) roll – back
Write ahead logging is a way ____________
a) to ensure atomicity
b) to keep data consistent
c) that records data on stable storage
d) all of the mentioned
Answer : d) all of the mentioned
In the write ahead logging a _____________ is maintained.
a) a memory
b) a system
c) a disk
d) a log record
Answer : d) a log record
An actual update is not allowed to a data item ____________
a) before the corresponding log record is written out to
stable storage
b) after the corresponding log record is written out to
stable storage
c) until the whole log record has been checked for
inconsistencies
d) all of the mentioned
Answer : a) before the corresponding log record is written
out to stable storage
The undo and redo operations must be _________ to guarantee
correct behaviour, even if a failure occurs during recovery process.
a) idempotent
b) easy
c) protected
d) all of the mentioned
Answer : a) idempotent
The system periodically performs checkpoints that consists
of the following operation(s) ____________ a) Putting all the log records currently
in main memory onto stable storage
b) putting all modified data residing in main memory onto
stable storage
c) putting a log record onto stable storage
d) all of the mentioned
Answer : d) all of the mentioned
Consider a transaction T1 that committed prior to checkpoint.
The record appears in the log before the record. Any modifications made by T1
must have been written to the stable storage either with the checkpoint or
prior to it. Thus at recovery time ____________
a) There is a need to
perform an undo operation on T1
b) There is a need to perform a redo operation on T1
c) There is no need to perform an undo and redo operation on
T1
d) All of the mentioned
Answer : c) There is no need to perform an undo and redo
operation on T1
Serializable schedules are ones where ____________
a) concurrent execution of transactions is equivalent to the
transactions executed serially
b) the transactions can be carried out one after the other
c) a valid result occurs after execution transactions
d) none of the mentioned
Answer : a) concurrent execution of transactions is
equivalent to the transactions executed serially
A locking protocol is one that ____________
a) governs how locks are acquired
b) governs how locks are released
c) governs how locks are acquired and released
d) none of the mentioned
Answer : c) governs how locks are acquired and released
The two phase locking protocol consists of ____________
a) growing & shrinking phase
b) shrinking & creation phase
c) creation & growing phase
d) destruction & creation phase
Answer : a) growing & shrinking phase
The growing phase is a phase in which?
a) A transaction may obtain locks, but does not release any
b) A transaction may obtain locks, and releases a few or all
of them
c) A transaction may release locks, but does not obtain any
new locks
d) A transaction may release locks, and does obtain new
locks
Answer : c) A transaction may release locks, but does not
obtain any new locks
The shrinking phase is a phase in which?
a) A transaction may obtain locks, but does not release any
b) A transaction may obtain locks, and releases a few or all
of them
c) A transaction may release locks, but does not obtain any
new locks
d) A transaction may release locks, and does obtain new
locks
Answer : c) A transaction may release locks, but does not
obtain any new locks
Dead Lock
Which of the following concurrency control protocols ensure
both conflict serializability and freedom from deadlock? I) 2-phase locking II)
Timestamp ordering
a) I only
b) II only
c) Both I and II
d) Neither I nor II
Answer : b) II only
What is a reusable resource?
a) that can be used by one process at a time and is not
depleted by that use
b) that can be used by more than one process at a time
c) that can be shared between various threads
d) none of the mentioned
Answer : a) that can be used by one process at a time and is
not depleted by that use
Which of the following condition is required for a deadlock
to be possible?
a) mutual exclusion
b) a process may hold allocated resources while awaiting
assignment of other resources
c) no resource can be forcibly removed from a process
holding it
d) all of the mentioned
Answer : d) all of the mentioned
A system is in the
safe state if ____________
a) the system can allocate resources to each process in some
order and still avoid a deadlock
b) there exist a safe sequence
c) all of the mentioned
d) none of the mentioned
Answer : a) the system can allocate resources to each
process in some order and still avoid a deadlock
The circular wait condition can be prevented by ____________
a) defining a linear ordering of resource types
b) using thread
c) using pipes
d) all of the mentioned
Answer : a) defining a linear ordering of resource types
Which one of the following is the deadlock avoidance
algorithm?
a) banker’s algorithm b) round-robin algorithm
c) elevator algorithm
d) karn’s algorithm
Answer : a) banker’s algorithm b) round-robin algorithm
What is the drawback of banker’s algorithm?
a) in advance processes rarely know how much resource they
will need
b) the number of processes changes as time progresses
c) resource once available can disappear
d) all of the mentioned
Answer : d) all of the mentioned
For an effective operating system, when to check for
deadlock?
a) every time a resource request is made
b) at fixed time intervals
c) every time a resource request is made at fixed time
intervals
d) none of the mentioned
Answer : c) every time a resource request is made at fixed
time intervals
A problem encountered in multitasking when a process is
perpetually denied necessary resources is called ____________
a) deadlock
b) starvation
c) inversion
d) aging
Answer : b) starvation
Which one of the following is a visual ( mathematical ) way
to determine the deadlock occurrence?
a) resource allocation graph
b) starvation graph
c) inversion graph
d) none of the mentioned
Answer : a) resource allocation graph
To avoid deadlock ____________
a) there must be a fixed number of resources to allocate
b) resource allocation must be done only once
c) all deadlocked processes must be aborted
d) inversion technique can be used Answers
Answer : a) there must be a fixed number of resources to allocate
Reviewed by technical_saurabh
on
June 06, 2021
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