Operating System CPU Scheduling Solved MCQs

 

Operating System CPU Scheduling Solved MCQs

In this section of Operating System CPU Scheduling MCQs.it contain Operating System Process Management – CPU Scheduling MCQs (Multiple Choice Questions Answers).All the MCQs (Multiple Choice Question Answers) requires in detail reading of Operating System subject as the hardness level of MCQs have been kept to advance level.

 

1.CPU-scheduling decisions may take place under which of the following  circumstances:

1. When a process switches from the running state to the waiting state
2. When a process switches from the running state to the ready state
3. When a process switches from the waiting state to the ready state
4. When a process terminates

• 1 and 2
• 1,2,3
• 2,3,4
• 1,2,3,4

D. 1,2,3,4

2.Under nonpreemptive scheduling, once the CPU has been allocated to a process, the process keeps the CPU until .

1. it releases the CPU by terminating
2. it releases the CPU by switching to the waiting state
3. it releases the CPU By switching to the ready state
4. it releases the CPU By switching to the Running state

• 1 and 2
• 1,2,3
• 2,3,4
• 1,2,3,4

A. 1 and 2

3.An I/O-bound program typically has

• a few long CPU bursts
• a few short CPU bursts
• many short CPU bursts
• None of the above

C. many short CPU bursts

4.A CPU-bound program might have

• a few long CPU bursts
• a few short CPU bursts
• many short CPU bursts
• None of the above

A. a few long CPU bursts

5.Whenever the CPU becomes idle, the operating system must select one of the processes in the ___ to be executed.

• execution queue
• process queue
• waiting queue
• ready queue

D. ready queue Explanation :

6.The ____ is the module that gives control of the CPU to the process selected by the short-term scheduler.

• interrupt
• scheduler
• dispatcher
• All of the above

C. dispatcher Explanation :

• Switching context
• Switching to user mode
• Jumping to the proper location in the user program to restart that program

7.The dispatcher should be as fast as possible, since it is invoked during every process switch. The time it takes for the dispatcher to stop one process and start another running is known as the ____.

• hardware latency
• dispatch latency
• memory latency
• RAM Latency

B. dispatch latency

 

1.Many criteria have been suggested for comparing CPU-scheduling algorithms.The criteria include which of the following:

1. CPU utilization
2. Throughput
3. Turnaround time
4. Waiting time
5. Response time

• 1,2
• 1,2,3
• 1,2,3,4
• 1,2,3,4,5

D. 1,2,3,4,5

2.We want to keep the CPU as busy as possible,This criteria refers to as

• Throughput
• CPU utilization
• Response time

B. CPU utilization

3.If the CPU is busy executing processes, then work is being done. One measure of work is the number of processes that are completed per time unit, called ____.

• Throughput
• CPU utilization
• Turnaround time
• Response time

A. Throughput

4.From the point of view of a particular process, the important criterion is how long it takes to execute that process. The interval from the time of submission of a process to the time of completion is the ____

• Throughput
• Waiting time
• Turnaround time
• Response time

C. Turnaround time Explanation :

5._________is the sum of the periods spent waiting in the ready queue.

• Throughput
• Waiting time
• Turnaround time
• Response time

B. Waiting time Explanation :

6.another measure is the time from the submission of a request until the first response is produced. This measure is called_____

• Throughput
• Waiting time
• Turnaround time
• Response time

D. Response time Explanation :

7.It is desirable to ______.

• minimize CPU utilization and throughput and to maximize turnaround time, waiting time, and response time
• maximize CPU utilization and throughput and to minimize turnaround time, waiting time, and response time
• maximize CPU utilization and turnaround time and to minimize throughput, waiting time, and response time
• minimize waiting time and throughput and to maximize turnaround time, CPU utilization, and response time

B. maximize CPU utilization and throughput and to minimize turnaround time, waiting time, and response time

 

1.In Which of the following algorithm the process that requests the CPU first is allocated the CPU first

• Shortest-Job-First Scheduling
• First-Come, First-Served Scheduling
• Priority Scheduling
• Round-Robin Scheduling

B. First-Come, First-Served Scheduling

2.Which of the following  scheduling algorithm is nonpreemptive

• Shortest-Job-First Scheduling
• First-Come, First-Served Scheduling
• Priority Scheduling
• Round-Robin Scheduling

B. First-Come, First-Served Scheduling

3.Which of the following  scheduling algorithm the average waiting time for the process to start execution  is often quite long

• Shortest-Job-First Scheduling
• Shortest-Job-First Scheduling
• First-Come, First-Served Scheduling
• Priority Scheduling

C. First-Come, First-Served Scheduling

4.Which of the following  scheduling algorithm associates with each process the length of the process’s next CPU burst

• Shortest-Job-First Scheduling
• First-Come, First-Served Scheduling
• Priority Scheduling
• Round-Robin Scheduling

A. Shortest-Job-First Scheduling

5.In Shortest-Job-First Scheduling If the next CPU bursts of two processes are the same, ____ scheduling is used to break the tie.

• Shortest-Job-First
• First-Come, First-Served
• Priority
• Round-Robin

B. First-Come, First-Served

6.more appropriate term for Which of the following scheduling method would be the shortest-next CPU-burst algorithm

• Round-Robin Scheduling
• First-Come, First-Served Scheduling
• Priority Scheduling
• Shortest-Job-First Scheduling

D. Shortest-Job-First Scheduling

7.The SJF algorithm can be

• preemptive Only
• nonpreemptive Only
• either preemptive or nonpreemptive
• None of the above

C. either preemptive or nonpreemptive

8.Which of the following  scheduling algorithm is used frequently in long-term scheduling

• Shortest-Job-First Scheduling
• First-Come, First-Served Scheduling
• Priority Scheduling
• Round-Robin Scheduling

A. Shortest-Job-First Scheduling

9.Which of the following  scheduling algorithm is provably optimal, in that it gives the minimum average waiting time for a given set of processes.

• Round-Robin Scheduling
• First-Come, First-Served Scheduling
• Priority Scheduling
• Shortest-Job-First Scheduling

D. Shortest-Job-First Scheduling

10.____ is sometimes called shortest-remaining-time-first scheduling

• Round-Robin Scheduling
• Preemptive SJF scheduling
• Priority Scheduling
• First-Come, First-Served Scheduling

B. Preemptive SJF scheduling

11.Which of the following Statement is TRUE for Shortest-Job-First Scheduling

1. The SJF algorithm is a special case of the general priority-scheduling algorithm
2. it can be implemented at the level of short-term CPU scheduling
3. A nonpreemptive SJF algorithm will allow the currently running process to finish its CPU burst
4. A preemptive SJF algorithm will preempt the currently executing process

• 1 ,2,4
• 1,2,3
• 1,3,4
• 1,2,3,4

C. 1,3,4 Explanation :

12.Which of the following Statement is TRUE for First-Come, First-Served Scheduling

1. When a process enters the ready queue, its PCB is linked onto the tail of the queue. When the CPU is free, it is allocated to the process at the head of the queue
2. FCFS scheduling algorithm is preemptive
3. The implementation of the FCFS policy is easily managed with a FIFO queue
4. the average waiting time under the FCFS policy is often quite small

• 1 ,2,4
• 1,3
• 1,3,4
• 1,2,3,4

B. 1,3 Explanation :

13.The next CPU burst of the newly arrived process may be shorter than what is left of the currently executing process. A _____ will preempt the currently executing process

• preemptive priority scheduling algorithm
• nonpreemptive SJF algorithm
• preemptive SJF algorithm
• First-Come, First-Served Scheduling

C. preemptive SJF algorithm

14.The ____ is a special case of the general priority-scheduling algorithm

• FCFS scheduling
• RR scheduling
• FCLS scheduling
• SJF algorithm

D. SJF algorithm

15.In which of the following Scheduling Algorithm A priority is associated with each process, and the CPU is allocated to the process with the highest priority.

• Round-Robin Scheduling
• Preemptive SJF scheduling
• Priority Scheduling
• First-Come, First-Served Scheduling

C. Priority Scheduling

16.In Priority Scheduling Equal-priority processes are scheduled in ___ order

• LIFO -Last In Fist Out
• FCFS - First Come First Served
• SJF - Shortest job First
• LILO -Last in Last Out

B. FCFS - First Come First Served

17.In Priority Scheduling Algorithm Which of the following stands True

• the priority (p) is equal to the next CPU burst. The smaller the CPU burst, the higher the priority
• the priority (p) is the inverse of the (predicted) next CPU burst. The smaller the CPU burst, the higher the priority
• the priority (p) is the inverse of the (predicted) next CPU burst. The larger the CPU burst, the lower the priority
• the priority (p) is equal to the next CPU burst. The larger the CPU burst, the lower The priority

C. the priority (p) is the inverse of the (predicted) next CPU burst. The larger the CPU burst, the lower the priority

18.The Priority Scheduling algorithm can be

• preemptive Only
• nonpreemptive Only
• either preemptive or nonpreemptive
• None of the above

C. either preemptive or nonpreemptive

19.A preemptive priority scheduling algorithm will preempt the CPU if

• The priority of the newly arrived process is higher than the priority of the currently running process
• The priority of the newly arrived process is Lower than the priority of the currently running process
• The priority of the newly arrived process is equal to the priority of the currently running process
• all of the above

A. The priority of the newly arrived process is higher than the priority of the currently running process

20.A nonpreemptive priority scheduling algorithm will simply put the new process at ___

• The tail of the ready queue.
• The head of the ready queue.
• head and tail of the ready queue
• None of the above

B. The head of the ready queue.

21.The indefinite blocking, or starvation is A major problem related to which of the following scheduling algorithm

• Shortest-Job-First Scheduling
• First-Come, First-Served Scheduling
• Priority Scheduling
• Round-Robin Scheduling

C. Priority Scheduling

22.Which of the following scheduling algorithm can leave some low priority processes waiting indefinitely?

• Shortest-Job-First Scheduling
• Priority Scheduling
• First-Come, First-Served Scheduling
• Round-Robin Scheduling

B. Priority Scheduling

23.A solution to the problem of indefinite blockage of low-priority processes is ______

• Switching
• Swapping
• Paging
• aging

D. aging

24.Which of the following statement is True for Aging

• Aging involves gradually increasing the priority of processes that wait in the system for a long time
• Aging involves gradually decreasing the priority of processes that wait in the system for a long time
• Aging involves gradually increasing the priority of processes that wait in the system for a small time
• Aging involves gradually decreasing the priority of processes that wait in the system for a small time

A. Aging involves gradually increasing the priority of processes that wait in the system for a long time

25.Which of the following Scheduling Algorithm is designed especially for timesharing systems?

• Shortest-Job-First Scheduling
• Priority Scheduling
• First-Come, First-Served Scheduling
• Round-Robin Scheduling

D. Round-Robin Scheduling

26.The RR scheduling algorithm is

• preemptive
• nonpreemptive
• either preemptive or nonpreemptive
• All of the above

A. preemptive

27.A Round-Robin Scheduling algorithm will simply put the new process at _____

• the tail of the ready queue
• the head of the ready queue.
• head and tail of the ready queue.
• None of the above

A. the tail of the ready queue

28.In which of the following scheduling algorithm The ready queue is treated as a circular queue. and we again treat the ready queue as a FIFO queue of processes

• Round-Robin Scheduling
• Preemptive SJF scheduling
• Priority Scheduling
• First-Come, First-Served Scheduling

A. Round-Robin Scheduling

29.In which of the following scheduling algorithm new processes are added to the tail of the ready queue. The CPU scheduler picks the first process from the ready queue, sets a timer to interrupt after 1 time quantum, and dispatches the process.

• Shortest-Job-First Scheduling
• Priority Scheduling
• First-Come, First-Served Scheduling
• Round-Robin Scheduling

D. Round-Robin Scheduling Explanation :

30.In Round-Robin Scheduling algorithm, The process may have a CPU burst of less than 1 time quantum. In this case:

• the timer will go off and will cause an interrupt to the operating system. A context switch will be executed, and the process will be put at the tail of the ready queue, The CPU scheduler will then select the next process in the ready queue
• the timer will go off and will cause an interrupt to the operating system. A context switch will be executed, and the process will be put at the head of the ready queue, The CPU scheduler will then select the next process in the ready queue
• the process itself will release the CPU voluntarily. The scheduler will then proceed to the next process in the ready queue
• the process itself will not release the CPU voluntarily. The scheduler will then proceed to the next process in the ready queue

C. the process itself will release the CPU voluntarily. The scheduler will then proceed to the next process in the ready queue

31.In Round-Robin scheduling algorithm, If the CPU burst of the currently running process is longer than 1 time quantum. In this case:

• The timer will go off and will cause an interrupt to the operating system. A context switch will be executed, and the process will be put at the tail of the ready queue, The CPU scheduler will then select the next process in the ready queue.
• the timer will go off and will cause an interrupt to the operating system. A context switch will be executed, and the process will be put at the head of the ready queue, The CPU scheduler will then select the next process in the ready queue
• the process itself will release the CPU voluntarily. The scheduler will then proceed to the next process in the ready queue
• the process itself will not release the CPU voluntarily. The scheduler will then proceed to the next process in the ready queue

A. The timer will go off and will cause an interrupt to the operating system. A context switch will be executed, and the process will be put at the tail of the ready queue, The CPU scheduler will then select the next process in the ready queue.

32.In which of the following scheduling algorithm the performance of the algorithm depends heavily on the size of the time quantum

• Shortest-Job-First Scheduling
• Priority Scheduling
• First-Come, First-Served Scheduling
• Round-Robin Scheduling

D. Round-Robin Scheduling