Operating System Questions and Answers

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Operating System Questions and Answers

These Operating System MCQ and Answers are most important for your upcoming examination including BCA, MCA, GATE, NET, UGC NET & other Interview examinations. and also these questions are ask in a job interview so these Operating System MCQs are very important for campus placement tests and job interviews From your graduations or degree. Here We the team live learns will update more questions soon.

Operating System, or OS, is a program that provides the interface between the user and computer hardware. It is also responsible for managing the other programs on a computer. An operating system can be compared to a government with different departments. The government ensures that thousands of people live together peacefully and work towards the same goal. The OS ensures that the different programs run on a computer work together without any conflicts. It manages memory, handles devices, and controls access to files. It works as an interface between users and computers.

Hey Students These Operating System MCQ and Answers – Implementing Real Time Operating Systems are asked in various examinations including BCA, MCA, GATE, and other tests. The questions based on the below Operating System MCQ and Answers – Implementing Real Time Operating Systems test your basic knowledge of MCQs on the topic of Operating Systems and the level of comprehension and grasp that you hold.

Here we share the top Operating System MCQ and Answers PDF these questions are really help to crack your interview On Operating System Questions.

Operating System MCQ and Answers – Implementing Real Time Operating Systems

1. What is Event latency?

a) the amount of time an event takes to occur from when the system started

b) the amount of time from the event occurrence till the system stops

c) the amount of time from event occurrence till the event crashes

d) the amount of time that elapses from when an event occurs to when it is serviced.

Answer: d

2. Interrupt latency refers to the period of time ____________

a) from the occurrence of an event to the arrival of an interrupt

b) from the occurrence of an event to the servicing of an interrupt

c) from arrival of an interrupt to the start of the interrupt service routine

d) none of the mentioned

Answer: c

3. Real time systems need to __________ the interrupt latency.

a) minimize

b) maximize

c) not bother about

d) none of the mentioned

Answer: a

4. The amount of time required for the scheduling dispatcher to stop one process and start another is known as ______________

a) event latency

b) interrupt latency

c) dispatch latency

d) context switch

Answer: c

5. The most effective technique to keep dispatch latency low is to ____________

a) provide non preemptive kernels

b) provide preemptive kernels

c) make it user programmed

d) run less number of processes at a time

Answer: b

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6. Priority inversion is solved by use of _____________

a) priority inheritance protocol

b) two phase lock protocol

c) time protocol

d) all of the mentioned

Answer: a

7. In a real time system the computer results ____________

a) must be produced within a specific deadline period

b) may be produced at any time

c) may be correct

d) all of the mentioned

Answer: a

8. In a safety critical system, incorrect operation ____________

a) does not affect much

b) causes minor problems

c) causes major and serious problems

d) none of the mentioned

Answer: c

9. Antilock brake systems, flight management systems, pacemakers are examples of ____________

a) safety critical system

b) hard real time system

c) soft real time system

d) safety critical system and hard real time system

Answer: d

10. In a ______ real time system, it is guaranteed that critical real time tasks will be completed within their deadlines.

a) soft

b) hard

c) critical

d) none of the mentioned

Answer: b

11. Some of the properties of real time systems include ____________

a) single purpose

b) inexpensively mass produced

c) small size

d) all of the mentioned

Answer: d

12. The amount of memory in a real time system is generally ____________

a) less compared to PCs

b) high compared to PCs

c) same as in PCs

d) they do not have any memory

Answer: a

13. What is the priority of a real time task?

a) must degrade over time

b) must not degrade over time

c) may degrade over time

d) none of the mentioned

Answer: b

14. Memory management units ____________

a) increase the cost of the system

b) increase the power consumption of the system

c) increase the time required to complete an operation

d) all of the mentioned

Answer: d

15. The technique in which the CPU generates physical addresses directly is known as ____________

a) relocation register method

b) real addressing

c) virtual addressing

d) none of the mentioned

Answer: b

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Operating System MCQ and Answers – Implementing Real Time Operating Systems

Here a lots of mcqs to help you to crack your Operating System Level Interview Questions and Answers with free pdf so guys be ready for your upcoming Interview exams.

1. What is Event latency?

a) the amount of time an event takes to occur from when the system started

b) the amount of time from the event occurrence till the system stops

c) the amount of time from event occurrence till the event crashes

d) the amount of time that elapses from when an event occurs to when it is serviced.

Answer: d

2. Interrupt latency refers to the period of time ____________

a) from the occurrence of an event to the arrival of an interrupt

b) from the occurrence of an event to the servicing of an interrupt

c) from arrival of an interrupt to the start of the interrupt service routine

d) none of the mentioned

Answer: c

3. Real time systems need to __________ the interrupt latency.

a) minimize

b) maximize

c) not bother about

d) none of the mentioned

Answer: a

4. The amount of time required for the scheduling dispatcher to stop one process and start another is known as ______________

a) event latency

b) interrupt latency

c) dispatch latency

d) context switch

Answer: c

5. The most effective technique to keep dispatch latency low is to ____________

a) provide non preemptive kernels

b) provide preemptive kernels

c) make it user programmed

d) run less number of processes at a time

Answer: b

6. Priority inversion is solved by use of _____________

a) priority inheritance protocol

b) two phase lock protocol

c) time protocol

d) all of the mentioned

Answer: a

7. In a real time system the computer results ____________

a) must be produced within a specific deadline period

b) may be produced at any time

c) may be correct

d) all of the mentioned

Answer: a

8. In a safety critical system, incorrect operation ____________

a) does not affect much

b) causes minor problems

c) causes major and serious problems

d) none of the mentioned

Answer: c

9. Antilock brake systems, flight management systems, pacemakers are examples of ____________

a) safety critical system

b) hard real time system

c) soft real time system

d) safety critical system and hard real time system

Answer: d

10. In a ______ real time system, it is guaranteed that critical real time tasks will be completed within their deadlines.

a) soft

b) hard

c) critical

d) none of the mentioned

Answer: b

11. Some of the properties of real time systems include ____________

a) single purpose

b) inexpensively mass produced

c) small size

d) all of the mentioned

Answer: d

12. The amount of memory in a real time system is generally ____________

a) less compared to PCs

b) high compared to PCs

c) same as in PCs

d) they do not have any memory

Answer: a

13. What is the priority of a real time task?

a) must degrade over time

b) must not degrade over time

c) may degrade over time

d) none of the mentioned

Answer: b

14. Memory management units ____________

a) increase the cost of the system

b) increase the power consumption of the system

c) increase the time required to complete an operation

d) all of the mentioned

Answer: d

15. The technique in which the CPU generates physical addresses directly is known as ____________

a) relocation register method

b) real addressing

c) virtual addressing

d) none of the mentioned

Answer: b

Operating System MCQ and Answers – Real Time CPU Scheduling

1. Using EDF algorithm practically, it is impossible to achieve 100 percent utilization due to __________

a) the cost of context switching

b) interrupt handling

c) power consumption

d) all of the mentioned

Answer: a

2. T shares of time are allocated among all processes out of N shares in __________ scheduling algorithm.

a) rate monotonic

b) proportional share

c) earliest deadline first

d) none of the mentioned

Answer: b

3. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.

A will have ______ percent of the total processor time.

a) 20

b) 15

c) 50

d) none of the mentioned

Answer: c

4. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.

B will have ______ percent of the total processor time.

a) 20

b) 15

c) 50

d) none of the mentioned

Answer: b

5. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.

C will have ______ percent of the total processor time.

a) 20

b) 15

c) 50

d) none of the mentioned

Answer: a

6. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.

If a new process D requested 30 shares, the admission controller would __________

a) allocate 30 shares to it

b) deny entry to D in the system

c) all of the mentioned

d) none of the mentioned

Answer: b

7. To schedule the processes, they are considered _________

a) infinitely long

b) periodic

c) heavy weight

d) light weight

Answer: b

8. If the period of a process is ‘p’, then what is the rate of the task?

a) p2

b) 2*p

c) 1/p

d) p

Answer: c

9. The scheduler admits a process using __________

a) two phase locking protocol

b) admission control algorithm

c) busy wait polling

d) none of the mentioned

Answer: c

10. The ____________ scheduling algorithm schedules periodic tasks using a static priority policy with preemption.

a) earliest deadline first

b) rate monotonic

c) first cum first served

d) priority

Answer: b

11. Rate monotonic scheduling assumes that the __________

a) processing time of a periodic process is same for each CPU burst

b) processing time of a periodic process is different for each CPU burst

c) periods of all processes is the same

d) none of the mentioned

Answer: a

12. In rate monotonic scheduling, a process with a shorter period is assigned __________

a) a higher priority

b) a lower priority

c) higher & lower priority

d) none of the mentioned

Answer: a

13. There are two processes P1 and P2, whose periods are 50 and 100 respectively. P1 is assigned higher priority than P2. The processing times are t1 = 20 for P1 and t2 = 35 for P2. Is it possible to schedule these tasks so that each meets its deadline using Rate monotonic scheduling?

a) yes

b) no

c) maybe

d) none of the mentioned

Answer: a

14. If a set of processes cannot be scheduled by rate monotonic scheduling algorithm, then __________

a) they can be scheduled by EDF algorithm

b) they cannot be scheduled by EDF algorithm

c) they cannot be scheduled by any other algorithm

d) none of the mentioned

Answer: c

15. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35. The total CPU utilization is?

a) 0.90

b) 0.74

c) 0.94

d) 0.80

Answer: c

16. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35. Can the processes be scheduled without missing the deadlines?

a) Yes

b) No

c) Maybe

d) None of the mentioned

Answer: b

17. Earliest deadline first algorithm assigns priorities according to ____________

a) periods

b) deadlines

c) burst times

d) none of the mentioned

Answer: b

18. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35. The total CPU utilization is ____________

a) 0.90

b) 0.74

c) 0.94

d) 0.80

Answer: c

19. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35., the priorities of P1 and P2 are?

a) remain the same throughout

b) keep varying from time to time

c) may or may not be change

d) none of the mentioned

Answer: b

Operating System MCQ and Answers – Basics Processes

1. 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

2. 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

3. In Operating Systems, which of the following is/are CPU scheduling algorithms?

a) Round Robin

b) Shortest Job First

c) Priority

d) All of the mentioned

Answer: d

4. 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

5. 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

6. Which one of the following is not a real time operating system?

a) VxWorks

b) QNX

c) RTLinux

d) Palm OS

Answer: d

7. The OS X has ____________

a) monolithic kernel

b) hybrid kernel

c) microkernel

d) monolithic kernel with modules

Answer: b

8. What is an operating system?

a) collection of programs that manages hardware resources

b) system service provider to the application programs

c) interface between the hardware and application programs

d) all of the mentioned

Answer: d

9. 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

10. 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

Operating System MCQ and Answers – Process Control Block

1. Which of the following is not the state of a process?

a) New

b) Old

c) Waiting

d) Running

Answer: b

2. 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

3. 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

4. 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

5. 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

6. What is the objective of multiprogramming?

a) Have a process running at all time

b) Have multiple programs waiting in a queue ready to run

c) To increase CPU utilization

d) None of the mentioned

Answer: c

7. A Process Control Block(PCB) does not contain which of the following?

a) Code

b) Stack

c) Bootstrap program

d) Data

Answer: c

8. The number of processes completed per unit time is known as __________

a) Output

b) Throughput

c) Efficiency

d) Capacity

Answer: b

9. 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

Operating System MCQ and Answers – Process Scheduling Queues

1. What is a long-term scheduler?

a) It selects processes which have to be brought into the ready queue

b) It selects processes which have to be executed next and allocates CPU

c) It selects processes which heave to remove from memory by swapping

d) None of the mentioned

Answer: a

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

13. Which of the following does not interrupt a running process?

a) A device

b) Timer

c) Scheduler process

d) Power failure

Answer: c

14. 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

15. 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

Operating System MCQ and Answers – Process Synchronization

1. If a process is executing in its critical section, then no other processes can be executing in their critical section. What is this condition called?

a) mutual exclusion

b) critical exclusion

c) synchronous exclusion

d) asynchronous exclusion

Answer: a

2. Which one of the following is a synchronization tool?

a) thread

b) pipe

c) semaphore

d) socket

Answer: c

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

Operating System MCQ and Answers – Process Creation

1. Cascading termination refers to the termination of all child processes if the parent process terminates ______

a) Normally

b) Abnormally

c) Normally or abnormally

d) None of the mentioned

Answer: c

2. 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

3. 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

4.  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

5. 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

6. 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

7. 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

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

a) wait

b) fork

c) exit

d) exec

Answer: a

Operating System MCQ and Answers – Inter Process Communication

1. 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

2. 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

3. 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 is 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. What is Interprocess 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

c) allows the processes to only synchronize their actions without communication

d) none of the mentioned

Answer: b

10. Message passing system allows processes to __________

a) communicate with each other without sharing the same address space

b) communicate with one another by resorting to shared data

c) share data

d) name the recipient or sender of the message

Answer: a

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