Operating System MCQs with Answers & OS Practice Questions

Operating Systems • Processes • Scheduling • Memory

Operating System MCQs with Answers and OS Practice Questions

Practice 100 operating system MCQs across four focused sets. Review OS basics, processes, CPU scheduling, context switching, deadlocks, memory management, system calls, kernels, interrupts and other core concepts used in computer science courses and technical interviews.

Learn the Main Operating System Concepts Through Practice

An operating system sits between computer hardware and the programs that use it. It manages resources such as the CPU, memory and devices, while also helping programs run, handle input and output, access files and respond to errors. Windows, Linux and macOS are familiar examples, but the same basic ideas also appear in servers, mobile devices and real-time systems.

Operating systems can feel difficult because several topics connect to each other. A process needs CPU time. The scheduler decides when it runs. A context switch moves the CPU from one process to another. Memory management decides where data and instructions are kept. Synchronization becomes important when processes share resources, and poor resource handling can lead to deadlock.

The four practice sets below follow that path. Set 1 gives you a broad introduction. Set 2 moves deeper into processes and scheduling. Set 3 focuses strongly on CPU scheduling and deadlocks. Set 4 brings several ideas together with system calls, critical sections, virtual memory, file allocation, interrupts and different types of operating systems.

Processes

Learn process states, process control blocks, queues, context switching, dispatching and how running programs are managed.

CPU scheduling

Practice FCFS, SJF, SRTF, Round Robin, priority scheduling, throughput, response time and turnaround time.

Memory

Review virtual memory, page faults, page replacement, fragmentation, swap space and the difference between main and secondary memory.

Deadlocks and synchronization

Practise mutual exclusion, hold-and-wait, circular wait, semaphores, safe states and Banker's algorithm.

A simple operating system study path

1Start with the OS basics

Use Set 1 for operating-system services, resource management, virtual memory and introductory process ideas.

2Understand processes

Use Set 2 for process states, control blocks, queues, schedulers, context switches and CPU bursts.

3Focus on scheduling

Use Set 3 for FCFS, SJF, SRTF, Round Robin, priority scheduling, deadlocks and semaphores.

4Finish with mixed OS review

Use Set 4 for system calls, critical sections, virtual memory, file allocation, interrupts and wider OS concepts.

Main topics covered in the OS MCQ series

Operating system servicesProcessesProcess states PCBContext switchingSchedulers DispatcherFCFSSJFSRTF Round RobinPriority schedulingDeadlocks SemaphoresBanker's algorithmVirtual memory Page faultsFragmentationSystem calls KernelsInterruptsFile allocationIPC
Study note: these sets were published in 2021 and include a few examples that name older operating systems or platform versions. The core process, scheduling, memory and synchronization concepts are still useful, but version-specific facts should be checked against current course material when needed.

Operating System MCQ Sets

The current series has four published sets with 25 questions in each set. Choose the set that matches the topic you want to revise.

Set 1: Operating System Basics, Memory and Processes

This 25-question starter set covers the purpose and services of an operating system, booting, multitasking, resource allocation, virtual memory and page faults. It also introduces real-time systems, system programs, concurrent processes, multiprocessing, CPU scheduling, deadlock avoidance, kernel and user modes, dispatching and overlays.

25 questionsOS basicsVirtual memoryProcessesDeadlock avoidance
Practice Set 1

Set 2: Process Management and CPU Scheduling

Set 2 moves deeper into process management. Questions cover medium- and long-term schedulers, context switching, the kernel, CPU-bound and I/O-bound processes, dispatchers, process control blocks, stacks, process states and device queues. The second half adds SJF, Round Robin, FCFS, starvation, deterministic modeling and ready-state concepts.

25 questionsPCBContext switchSJFRound Robin
Practice Set 2

Set 3: CPU Scheduling, Deadlocks and Semaphores

This 25-question set has the strongest CPU-scheduling focus. It includes FCFS, FIFO, SJF, SRTF, Round Robin and priority scheduling, plus throughput, response time and turnaround time. The later questions move into deadlock conditions, safe and unsafe states, semaphores, hold-and-wait, Banker's algorithm and resource-allocation ideas.

25 questionsCPU schedulingDeadlocksSemaphoresBanker's algorithm
Practice Set 3

Set 4: System Calls, Memory, File Allocation and Mixed OS Review

Set 4 mixes several important OS topics. It covers system calls, critical-section rules, error handling, network and real-time operating systems, command interpreters, FIFO page replacement, fragmentation, hybrid kernels, virtual memory, context switching, file-allocation methods, the Unix fork system call, process termination, paging, interprocess communication and information protection.

25 questionsSystem callsCritical sectionsVirtual memoryIPC
Practice Set 4

How to Use These Operating System MCQs

1Learn the process story first

Understand what a process is, how it changes state and why the scheduler moves CPU time between processes.

2Practise scheduling on paper

For FCFS, SJF, SRTF and Round Robin, work through small examples instead of only memorising definitions.

3Connect memory and synchronization

After scheduling, revise page faults, virtual memory, critical sections and deadlocks so the topics make sense as one system.

Who Can Use This Operating System Practice Series?

These operating system MCQs are useful for computer science and IT students, university quizzes and exams, introductory systems courses and entry-level technical interview revision. MCQs are best for checking concepts, so use them together with scheduling problems, memory-management exercises and your current course notes.

Operating System MCQs FAQ

What topics are covered in these operating system MCQs?

The four sets cover operating-system services, processes, process states, CPU scheduling, context switching, dispatching, deadlocks, semaphores, virtual memory, page faults, kernels, system calls, critical sections, interrupts, file allocation and interprocess communication.

Which operating system set should a beginner start with?

Start with Set 1. It gives the broadest introduction to operating-system services, resources, virtual memory, processes and basic scheduling ideas before the later sets become more focused.

Which set is best for CPU scheduling MCQs?

Set 3 is the strongest scheduling set. It includes FCFS, SJF, SRTF, Round Robin, priority scheduling, throughput, response time and turnaround time. Set 2 also contains several scheduling questions.

Which sets cover deadlocks?

Deadlock ideas appear in Sets 1, 3 and 4. Set 3 gives the most focused practice on deadlock conditions, safe and unsafe states, semaphores and Banker's algorithm.

Are these OS MCQs useful for technical interviews?

They can help with entry-level concept revision, especially processes, scheduling, memory and deadlocks. For interviews, also practise explaining these ideas in your own words and solving small scheduling or synchronization problems.

How many operating system questions are in the current series?

The current series contains four published sets with 25 questions in each set, for 100 operating system MCQs in total.

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