Concurrent process are
A. process that do not overlap in time
B. process that overlap in time
C. processes that executed by a processor at the same time
D. none of the above
ANSWER: C
The only state transition that is initiated by the user process itself is
A. Block
B. Dispatch
C. Wakeup
D. None of the above
ANSWER: A
which of the following are real time operating system
A. an on-line railway reservation system
B. a process control system
C. aircraft control system
D. payroll processing system
ANSWER: C
Critical region is
A. A part of the operating system which is not allowed to be accessed by any process
B. A set of instructions that access common shared resource which exclude one another in time
C. The portion of the main memory which can be accessed only by one process at a time
D. None of the above
ANSWER: B
in a time sharing operating system, when the time slot given to a process is completed, the process goes from running state to the
A. BLOCKED state
B. READY state
C. SUSPENDED state
D. TERMINATED state
ANSWER: B
At a particular time, the value of a counting semaphore is 10. It will become 7 after
A. 3 V operations
B. 3 P operations
C. 5 V operations and 2 P operations
D. 13 P operations and 10 V operations
ANSWER: D
Semaphores are used to solve the problem of
A. Race condition
B. Process synchronization
C. Mutual exclusion
D. None of the above
ANSWER: B
Pre-emptive scheduling is the strategy of the temporarily suspending a running process
A. Before the CPU time slice expires
B. To allow starving process to run
C. When it requests I/O
D. None of the above
ANSWER: C
Mutual exclusion problem occurs between
A. Two disjoint process that do not interact
B. Process that share resources
C. Process that do not use the same resources
D. None of the above
ANSWER: B
Which of the following is a service not supported by the operating system?
A. Protection
B. Accounting
C. Compilation
D. I/O operation
ANSWER: C
In round robin CPU scheduling, as the quantum is increased, the average turn around time
A. increases
B. decreases
C. remains constant
D. varies irregularly
ANSWER: D
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 is resident in the memory
D. a single user can execute many programs in the same time
ANSWER: C
In which of the following scheduling policies does context switching never take place?
A. Round-robin
B. SJF
C. Pre-emptive
D. FCFS
ANSWER: D
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
In real time operating system, which of the following is most suitable scheduling scheme?
A. Round-robin
B. FCFS
C. Pre-emptive scheduling
D. Random scheduling
ANSWER: A
Which of the following scheduling algorithms gives minimum average waiting time
A. FCFS
B. SJF
C. Round-Robin
D. Priority
ANSWER: B
Which of the following scheduling policy is well suited for a time sharing operating system
A. SJF
B. Round-robin
C. FCFS
D. Priority
ANSWER: B
Process is
A. Program under execution
B. Content of main memory
C. A job in secondary memory
D. Program on disk
ANSWER: A
Convoy effect is the problem of:
A. FCFS
B. SJF
C. SRTF
D. Round Robin
ANSWER: A
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 these
ANSWER: A
Which one of the following cannot be scheduled by the kernel?
A. Kernel level
B. user level thread
C. process
D. none of these
ANSWER: A
a thread is also called:
A. Light weight process (LWP)
B. Heavy weight process (HWP)
C. Process
D. None of these
ANSWER: A
Inter-process communication:
A. Is required for all processes
B. Is usually done via disk drives
C. Needed in case of co-operative processes
D. Is never necessary
ANSWER: C
Interval between the time of submission and completion of the job is called:
A. Waiting time
B. Turnaround time
C. Throughput
D. Response time
ANSWER: B
Program ‘preemption’ is:
A. Forced de allocation of the CPU from a program which is executing on the CPU.
B. Release of CPU by the program after completing its task
C. A program terminating itself due to detection of an error
D. None of the above
ANSWER: A
Difference of burst time and turnaround time is:
A. Waiting time
B. Response time
C. Actual time
D. None of the above
ANSWER: c
CPU scheduler is also known as:
A. Long term scheduler
B. Short term scheduler
C. Midterm scheduler
D. None
ANSWER: B
Long term scheduler is also known as:
A. Short term scheduler
B. CPU scheduler
C. Job scheduler
D. Midterm scheduler
ANSWER: C
Which is not the state of process?
A. Blocked
B. Running
C. Ready
D. Privileged
ANSWER: D
SJF is:
A. Preemptive
B. Non Preemptive
C. Both (A. and (B.
D. None of the above
ANSWER: C
A process can be
A. Single threaded
B. Multithreaded
C. Both (A. and (B.
D. none of the mentioned
ANSWER: C
Which one of the following is not shared by threads?
A. program counter
B. Stack
C. both (A. and (B.
D. none of the mentioned
ANSWER: C
One of the disadvantages of the priority scheduling algorithm is that :
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 these
ANSWER: C
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. SRTF scheduling – Shortest Remaining Time First
ANSWER: D
Scheduling is:
A. allowing a job to use the processor
B. Making proper use of processor
C. Both a and b
D. None of these
ANSWER: C
The 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
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
The degree of multi-programming is
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: B
The Process Control Block is
A. Process type variable
B. Data Structure
C. a secondary storage section
D. a Block in memory
ANSWER: B
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 number of processes completed per unit time is known as __________.
A. Output
B. Throughput
C. Efficiency
D. Capacity
ANSWER: B
Time quantum is defined in
A. shortest job scheduling algorithm
B. round robin scheduling algorithm
C. priority scheduling algorithm
D. multilevel queue scheduling algorithm
ANSWER: B
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
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
The systems which allows 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
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: A
In Unix, Which system call creates the new process?
a) fork
b) create
c) new
d) none of the mentioned
ANSWER: A
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
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
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
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
A process stack does not contain
a) Function parameters
b) Local variables
c) Return addresses
d) PID of child process
ANSWER: D
A Process Control Block(PCB) does not contain which of the following :
a) Code
b) Stack
c) Bootstrap program
d) Data
ANSWER: C
Which of the following is not the state of a process?
a) New
b) Old
c) Waiting
d) Running
ANSWER: B
The Process Control Block is:
a) Process type variable
b) Data Structure
c) A secondary storage section
d) A Block in memory
ANSWER: B
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
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: A
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: D
An IPC facility provides at least two operations :
a) write & delete message
b) delete & receive message
c) send & delete message
d) receive & send message
ANSWER: D
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: A
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: D
A parent process calling _____ system call will be suspended until children processes terminate.
a) wait
b) fork
c) exit
d) exec
ANSWER: C
4. 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
7. 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: B
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
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
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: B
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: C
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
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
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
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
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: D
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: B
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: D
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: A
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
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
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
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
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
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: A
CPU scheduling is the basis of ___________
a) multiprocessor systems
b) multiprogramming operating systems
c) larger memory sized systems
d) none of the mentioned
ANSWER: A
With multiprogramming, ______ is used productively.
a) time
b) space
c) money
d) all of the mentioned
ANSWER: A
The two steps of a process execution are :
a) I/O & OS Burst
b) CPU & I/O Burst
c) Memory & I/O Burst
d) OS & Memory Burst
ANSWER: B
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
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
The switching of the CPU from one process or thread to another is called :
a) process switch
b) task switch
c) context switch
d) all of the mentioned
ANSWER: C
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
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
Turnaround time is :
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
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: D
Waiting time is :
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: A
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
Response time is :
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
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
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
5. The 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
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
Scheduling is :
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
The most optimal scheduling algorithm is :
a) FCFS – First come First served
b) SJF – Shortest Job First
c) RR – Round Robin
d) None of the mentioned
ANSWER: B
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
The FCFS algorithm is particularly troublesome for ____________
a) time sharing systems
b) multiprogramming systems
c) multiprocessor systems
d) operating systems
ANSWER: B
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
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: C
8. ‘Aging’ is :
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
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
Which of the following scheduling algorithms gives minimum average waiting time ?
a) FCFS
b) SJF
c) Round – robin
d) Priority
ANSWER: B
