Operating System MCQs with Answers
Practice important Operating System MCQs with answers and explanations.
Chapter: 14
Q361:
Preemptive scheduling allows a process to be _______ during its execution.
A. Terminated
B. Interrupted
C. Suspended
D. Finished
Correct Answer:
B
Chapter: 14
Q362:
Which scheduling criterion refers to the time taken for a process to complete after submission?
A. Turnaround time
B. Waiting time
C. CPU utilization
D. Response time
Correct Answer:
A
Chapter: 14
Q363:
What is the goal of CPU scheduling in a system?
A. Minimize CPU utilization
B. Maximize throughput
C. Maximize waiting time
D. None of the above
Correct Answer:
B
Chapter: 14
Q364:
Which algorithm is based on giving the CPU to the process that requests it first?
A. FCFS
B. SJF
C. SRTF
D. Priority Scheduling
Correct Answer:
A
Chapter: 14
Q365:
FCFS is a _______ scheduling algorithm.
A. Preemptive
B. Non-preemptive
C. Both
D. A
Correct Answer:
B
Chapter: 14
Q366:
Which of the following best describes the Gantt chart for the process execution order P1, P2, P3?
A. First-come, first-served
B. Shortest job first
C. Shortest remaining time first
D. Priority scheduling
Correct Answer:
A
Chapter: 14
Q367:
When does the convoy effect occur in FCFS scheduling?
A. When short processes wait behind long processes
B. When processes are prioritized by memory usage
C. When I/O requests dominate CPU time
D. None of the above
Correct Answer:
A
Chapter: 14
Q368:
The average waiting time in FCFS is calculated by _______.
A. Dividing total CPU time by number of processes
B. Average time spent in I/O divided by number of processes
C. Summing all individual waiting times and dividing by number of processes
D. Summing burst times and dividing by the number of processes
Correct Answer:
C
Chapter: 14
Q369:
In the system where processes P2, P3, and P1 arrive in that order, what is the average waiting time?
A. 3
B. 6
C. 17
D. 7
Correct Answer:
B
Chapter: 14
Q370:
The term "ready queue" refers to _______.
A. A list of processes waiting for I/O
B. A list of processes waiting for CPU time
C. A list of processes ready for memory allocation
D. A list of completed processes
Correct Answer:
B
Chapter: 14
Q371:
Which of the following is a feature of preemptive scheduling?
A. The CPU can be reallocated before the process finishes its burst time.
B. The process executes until termination without interruption.
C. The process must wait for I/O before the CPU is allocated.
D. None of the above
Correct Answer:
A
Chapter: 14
Q372:
Which of the following scheduling algorithms is best for batch systems?
A. FCFS
B. SJF
C. Multilevel queues
D. All of the above
Correct Answer:
A
Chapter: 14
Q373:
In a non-preemptive system, once the CPU is allocated to a process, it will keep the CPU until _______.
A. The process completes execution
B. The process terminates
C. The process switches to waiting state
D. The process switches to ready state
Correct Answer:
C
Chapter: 14
Q374:
What happens when the CPU becomes idle in a multiprogramming system?
A. The OS selects a new process to execute.
B. The system enters a shutdown state.
C. The running process is terminated.
D. No action is taken.
Correct Answer:
A
Chapter: 14
Q375:
Fill in the blank: A process that requests the CPU first is allocated the CPU first in the _______ scheduling algorithm.
A. First-Come-First-Served (FCFS)
B. Shortest Job First (SJF)
C. Shortest Remaining Time First (SRTF)
D. Priority Scheduling
Correct Answer:
A
Chapter: 14
Q376:
Fill in the blank: In FCFS scheduling, the average waiting time can vary substantially if the processes' _______ vary greatly.
A. Memory requirements
B. Burst times
C. I/O times
D. Priority levels
Correct Answer:
B
Chapter: 15
Q377:
The Shortest-Job-First (SJF) scheduling algorithm assigns the CPU to the process with the __________ next CPU burst.
A. longest
B. shortest
C. average
D. equal
Correct Answer:
B
Chapter: 15
Q378:
In Shortest-Job-First (SJF) scheduling, if two processes have the same CPU burst, which scheduling is used to break the tie?
A. Round Robin
B. Priority Scheduling
C. FCFS
D. SRTF
Correct Answer:
C
Chapter: 15
Q379:
The predicted value for the next CPU burst in SJF is given by the equation τn+1 = αtn + (1-α)τn, where 0 ≤ α ≤ 1. What does α represent?
A. Time unit
B. Process priority
C. Smoothing constant
D. CPU burst
Correct Answer:
C
Chapter: 15
Q380:
Shortest-Job-First scheduling is a __________ algorithm.
A. preemptive
B. non-preemptive
C. hybrid
D. both
Correct Answer:
B