1690 + Mcqs in Operating System McqOptions

1.	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» C. non – critical section

Discussion

2.	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» C. aging

Discussion

3.	Concurrent access to shared data may result in :
A.	data consistency
B.	data insecurity
C.	data inconsistency
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

4.	Which of the following scheduling algorithms gives minimum average waiting time ?
A.	FCFS
B.	SJF
C.	Round – robin
D.	Priority
Answer» C. Round – robin

Discussion

5.	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» E.

Discussion

6.	A solution to the problem of indefinite blockage of low – priority processes is :
A.	Starvation
B.	Wait queue
C.	Ready queue
D.	Aging
Answer» E.

Discussion

7.	‘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» E.

Discussion

8.	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 the mentioned
Answer» D. none of the mentioned

Discussion

9.	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» B. the inverse of the predicted next CPU burst

Discussion

10.	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» E.

Discussion

11.	The FCFS algorithm is particularly troublesome for ____________
A.	time sharing systems
B.	multiprogramming systems
C.	multiprocessor systems
D.	operating systems
Answer» C. multiprocessor systems

Discussion

12.	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» C. it is too complex to understand

Discussion

13.	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» C. RR – Round Robin

Discussion

14.	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» E.

Discussion

15.	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» C. Shortened; Shortened

Discussion

16.	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» C. Earliest Deadline First

Discussion

17.	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» D. critical ratio

Discussion

18.	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» B. tQ = 40ms

Discussion

19.	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» B. making proper use of processor

Discussion

20.	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» C. Shortest job first

Discussion

21.	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» C. first executes the job that needs minimal processor

Discussion

22.	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» B. use minimal resources

Discussion

23.	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» B. assigning ready processes to waiting queue

Discussion

24.	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» B. using very small time slices converts it into First come First served scheduling algorithm

Discussion

25.	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» C. All of the mentioned

Discussion

26.	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» C. the total time taken from submission time till the response is output

Discussion

27.	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» C. the total time spent in the running queue

Discussion

28.	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» E.

Discussion

29.	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» B. decrease CPU utilization

Discussion

30.	Dispatch latency is :
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» D. none of the mentioned

Discussion

31.	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» E.

Discussion

32.	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» C. When a process switches from the waiting state to the ready state

Discussion

33.	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» D. ready, long term

Discussion

34.	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» D. a few very short I/O bursts

Discussion

35.	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» C. Memory & I/O Burst

Discussion

36.	With multiprogramming, ______ is used productively.
A.	time
B.	space
C.	money
D.	all of the mentioned
Answer» B. space

Discussion

37.	CPU scheduling is the basis of ___________
A.	multiprocessor systems
B.	multiprogramming operating systems
C.	larger memory sized systems
D.	none of the mentioned
Answer» C. larger memory sized systems

Discussion

38.	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» C. process

Discussion

39.	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» B. classification of ready queue is permanent

Discussion

40.	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» E.

Discussion

41.	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» C. priority scheduling algorithm

Discussion

42.	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» C. parent process

Discussion

43.	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» B. CPU is allocated to the process with lowest priority

Discussion

44.	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» B. shortest job scheduling

Discussion

45.	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» C. response time

Discussion

46.	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» C. execution queue

Discussion

47.	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» B. interrupt

Discussion

48.	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» E.

Discussion

49.	How does the Hardware trigger an interrupt ?
A.	Sending signals to CPU through 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» B. Executing a special program called interrupt program

Discussion

50.	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» C. Bottom Layer(N) is the hardware

Discussion

Explore topic-wise MCQs in Testing Subject.

The segment of code in which the process may change common variables, update tables, write into files is known as :

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 :

Concurrent access to shared data may result in :

Which of the following scheduling algorithms gives minimum average waiting time ?

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 solution to the problem of indefinite blockage of low – priority processes is :

‘Aging’ is :

One of the disadvantages of the priority scheduling algorithm is that :

An SJF algorithm is simply a priority algorithm where the priority is :

Preemptive Shortest Job First scheduling is sometimes called :

The FCFS algorithm is particularly troublesome for ____________

The real difficulty with SJF in short term scheduling is :

The most optimal scheduling algorithm is :

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

Under multiprogramming, turnaround time for short jobs is usually ________ and that for long jobs is slightly ___________

Which of the following algorithms tends to minimize the process flow time ?

Orders are processed in the sequence they arrive if _______ rule sequences the jobs.

Scheduling is :

The strategy of making processes that are logically runnable to be temporarily suspended is called :

The FIFO algorithm :

Complex scheduling algorithms :

The portion of the process scheduler in an operating system that dispatches processes is concerned with :

With round robin scheduling algorithm in a time shared system,

Round robin scheduling falls under the category of :

Response time is :

Waiting time is :

Turnaround time is :

Scheduling is done so as to :

Dispatch latency is :

The switching of the CPU from one process or thread to another is called :

In the following cases non – preemptive scheduling occurs :

A process is selected from the ______ queue by the ________ scheduler, to be executed.

An I/O bound program will typically have :

The two steps of a process execution are :

With multiprogramming, ______ is used productively.

CPU scheduling is the basis of ___________

Which one of the following can not be scheduled by the kernel?

In multilevel feedback scheduling algorithm

Process are classified into different groups in

Time quantum is defined in

In priority scheduling algorithm, when a process arrives at the ready queue, its priority is compared with the priority of

In priority scheduling algorithm

Which scheduling algorithm allocates the CPU first to the process that requests the CPU first?

The interval from the time of submission of a process to the time of completion is termed as

The processes that are residing in main memory and are ready and waiting to execute are kept on a list called

Which module gives control of the CPU to the process selected by the short-term scheduler?

Which operation is performed by an interrupt handler ?

How does the Hardware trigger an interrupt ?

In the layered approach of Operating Systems :

Under multiprogramming, turnaround time for short jobs is usually and that for long jobs is slightly ___

A process is selected from the queue by the __ scheduler, to be executed.