650+ Operating System (OS) Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Computer Science Engineering (CSE) , Information Technology Engineering (IT) , Bachelor of Science in Computer Science FY (BSc CS) , Bachelor of Computer Applications (BCA) , Bachelor of Science in Computer Science (BSc CS) .

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251.	A parent process calling system call will be suspended until children processes terminate.
A.	wait
B.	fork
C.	exit
D.	exec
Answer» A. wait

252.	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

253.	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

254.	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

255.	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

256.	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

257.	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

258.	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

259.	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

260.	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

261.	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

267.	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

268.	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» B. critical section

269.	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

270.	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

262.	In indirect communication between
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

263.	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

264.	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

265.	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

266.	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

271.	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

272.	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

273.	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

274.	An un-interruptible unit is known as
A.	single
B.	atomic
C.	static
D.	none of the mentioned
Answer» B. atomic

275.	TestAndSet instruction is executed
A.	after a particular process
B.	periodically
C.	atomically
D.	none of the mentioned
Answer» C. atomically

650+ Operating System (OS) Solved MCQs

A parent process calling system call will be suspended until children processes terminate.

Cascading termination refers to termination of all child processes before the parent terminates

In UNIX, each process is identified by its

The child process can

The child process completes execution, but the parent keeps executing, then the child process is known as

What is Inter process communication?

Message passing system allows processes to

Which of the following two operations are provided by the IPC facility?

Messages sent by a process

The link between two processes P and Q to send and receive messages is called

Which of the following are TRUE for direct communication?

In indirect communication between

In the non blocking send

In the Zero capacity queue

The Zero Capacity queue

Concurrent access to shared data may result in

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

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

Which of the following conditions must be satisfied to solve the critical section problem?

Mutual exclusion implies that

Bounded waiting implies that there exists a bound on the number of times a process is allowed to enter its critical section

A minimum of variable(s) is/are required to be shared between processes to solve the critical section problem.

In the bakery algorithm to solve the critical section problem

An un-interruptible unit is known as

TestAndSet instruction is executed

Semaphore is a/an to solve the critical section problem.

What are the two atomic operations permissible on semaphores?

What are Spinlocks?

What is the main disadvantage of spinlocks?

The wait operation of the semaphore basically works on the basic system call.

The signal operation of the semaphore basically works on the basic system call.

If the semaphore value is negative

The code that changes the value of the semaphore is

What will happen if a non-recursive mutex is locked more than once?

What is a semaphore?

What are the two kinds of semaphores?

What is a mutex?

A binary semaphore is a semaphore with integer values

Semaphores are mostly used to implement

The bounded buffer problem is also known as

In the bounded buffer problem, there are the empty and full semaphores that

To ensure difficulties do not arise in the readers – writers problem are given exclusive access to the shared object.

The dining – philosophers problem will occur in case of

A deadlock free solution to the dining philosophers problem

A monitor is a type of

A monitor is characterized by

A procedure defined within a can access only those variables declared locally within the and its formal parameters.

If no process is suspended, the signal operation

A collection of instructions that performs a single logical function is called

What are the operations that can be invoked on a condition variable?

276.	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

277.	What are the two atomic operations permissible on semaphores?
A.	wait
B.	stop
C.	hold
D.	none of the mentioned
Answer» A. wait

278.	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

279.	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

280.	The wait operation of the semaphore basically works on the basic system call.
A.	stop()
B.	block()
C.	hold()
D.	wait()
Answer» B. block()

281.	The signal operation of the semaphore basically works on the basic system call.
A.	continue()
B.	wakeup()
C.	getup()
D.	start()
Answer» B. wakeup()

282.	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

283.	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

284.	What will happen if a non-recursive mutex is locked more than once?
A.	starvation
B.	deadlock
C.	aging
D.	signaling
Answer» B. deadlock

285.	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