Operating System MCQ (Multiple Choice Questions)
1. What is the main software that acts as a bridge between a computer’s user and its hardware?
a) Application software
b) Utility tool
c) Compiler
d) Operating system
Explanation: The operating system manages hardware resources and provides common services for application programs, acting as an intermediary between users and hardware.
2. Which component oversees the overall functioning of a computer and enables user interaction?
a) Motherboard
b) Application program
c) Interpreter
d) Operating system
Explanation: The OS coordinates hardware, manages resources, and provides the interface (GUI or CLI) through which users interact with the computer.
3. What are the key roles of an operating system for user ease?
a) Managing CPU planning and performance
b) Handling data files
c) Overseeing input/output devices and interfaces
d) All of the above
Explanation: Modern operating systems handle process management, file system operations, device I/O, memory allocation, security, and more.
4. Which operating system supports only one user at a time?
a) Unix
b) Linux
c) Windows 95
d) MS-DOS
Explanation: MS-DOS was a single-user, single-tasking operating system designed primarily for personal computers.
5. What does MS-DOS stand for?
a) Microsoft Disk Operating System
b) Microsoft Double Operating System
c) Microsoft Dual Operating System
d) Microsoft Dual Operation System
Explanation: MS-DOS (Microsoft Disk Operating System) was developed by Microsoft for IBM PCs and focused on disk management.
6. An OS that permits only one task or user simultaneously is called?
a) Multi-user OS
b) Single-user OS
c) Multi-tasking OS
d) Single-processing OS
Explanation: Single-user operating systems allow only one user and typically one task at a time (e.g., early DOS versions).
7. What was the initial command-line based single-user OS for personal computers?
a) Windows 9X
b) VMS
c) Windows 95
d) PC-DOS
Explanation: PC-DOS (IBM’s version) and MS-DOS were the dominant command-line single-user OS in the early PC era.
8. Which are examples of single-user operating systems?
a) Windows 95
b) Windows 9X
c) MS-DOS
d) Both b and c
Explanation: Both MS-DOS and early Windows 9x series were primarily single-user systems (though Windows 9x supported basic multitasking).
9. Which OS can handle multiple tasks at once?
a) All of the above
b) Unix
c) Windows 95
d) Linux
Explanation: Unix, Linux, and Windows 95 (and later) all support multitasking — running multiple processes concurrently.
10. Which OS type prioritizes tasks based on urgency and resources?
a) Time-sharing OS
b) Real-time OS
c) Multi-user OS
d) Batch processing OS
Explanation: Batch processing OS groups similar jobs and executes them in sequence, often prioritizing based on job requirements.
11. Identify a batch processing operating system.
a) Linux
b) VMS
c) Unix
d) Mac OS
Explanation: Unix (and many of its derivatives) can be used in batch processing mode, although it is better known for interactive/time-sharing use.
12. Why is an operating system essential in computers?
a) Resource management
b) User-friendliness
c) Hardware control
d) All of these
Explanation: The OS manages hardware, provides abstraction, improves usability, and enables efficient resource sharing.
13. When was the debut version of Microsoft Windows released?
a) November 1985
b) October 1986
c) August 1980
d) None
Explanation: Windows 1.0 was released on November 20, 1985 as a graphical shell running on top of MS-DOS.
14. Which Windows release in 1990 featured enhanced graphics and 386 processor support?
a) Windows 1.0
b) Windows 2.0
c) Windows 3.0
d) None
Explanation: Windows 3.0 (1990) introduced protected mode, better memory management, and improved GUI.
15. Which 1995 Windows version added GUI, TCP/IP, and networking features?
a) MS-DOS
b) Windows 98
c) Windows 95
d) Windows NT
Explanation: Windows 95 brought a full 32-bit GUI, integrated TCP/IP stack, and Plug and Play support.
16. What does GUI expand to?
a) Graphical User Intercommunication
b) Graphical User Interface
c) Graphics User Interface
d) Graphics User Intercommunication
Explanation: GUI stands for Graphical User Interface — visual icons, windows, menus instead of text commands.
17. Who created the first GUI in the 1970s?
a) Microsoft
b) IBM
c) Intel
d) Xerox Corporation
Explanation: Xerox PARC developed the Alto computer (1973) with the first modern GUI concepts (windows, icons, mouse).
18. What is another term for Command Line Interface (CLI)?
a) Character User Interface
b) Command User Interface
c) Command User Intercom
d) None
Explanation: CLI is also commonly called CUI (Character User Interface) because it uses text/character-based interaction.
19. Which is not a core function of an OS?
a) Processor management
b) File management
c) Resource management
d) Networking
Explanation: Networking is supported by many OS but is not considered a core/fundamental function like process, memory, file, and device management.
20. Processing all transactions together at once is termed?
a) Database system
b) Real-time system
c) Batch processing
d) Time-sharing system
Explanation: Batch processing collects similar jobs and processes them as a group without user interaction.
21. Microsoft Windows is characterized as?
a) Multitasking, multiuser
b) Multiuser, single-tasking
c) Single-user, multitasking
d) Single-user, single-tasking
Explanation: Consumer versions of Windows are primarily single-user but support preemptive multitasking.
22. Executing multiple files on one processor simultaneously is?
a) Single-tasking
b) Scheduling
c) Multiprocessing
d) Multitasking
Explanation: Multiprocessing = multiple processors; multitasking = multiple processes sharing one processor.
23. Running several tasks or programs at the same time is?
a) Multithreading
b) Multiprocessing
c) Multitasking
d) Multicomputing
Explanation: Multitasking allows several programs to appear to run simultaneously by rapidly switching the CPU.
24. Handling multiple programs via several processors is known as?
a) Multiprogramming
b) Multitasking
c) Time-sharing
d) Multiprocessing
Explanation: Multiprocessing uses multiple CPUs/processors to run programs in true parallel.
25. What is RTOS an abbreviation for?
a) Reliable Time OS
b) Real Time OS
c) Reboot Time OS
d) None
Explanation: Real-Time Operating System — guarantees response within strict time constraints.
26. A system executing multiple processes at once is?
a) Multiprogramming
b) Batch processing
c) Multiprocessing
d) Real-time processing
Explanation: Multiprogramming keeps multiple programs in memory to improve CPU utilization.
27. Loading the OS into computer memory is called?
a) Processing
b) Booting
c) Starting
d) Synchronizing
Explanation: Booting is the process of loading the operating system into RAM during startup.
28. Which program resides in ROM?
a) Application
b) OS program
c) Bootstrap
d) Both b and c
Explanation: The bootstrap loader (or boot ROM) is stored in ROM/EEPROM and starts the OS loading process.
29. The bootstrap loader’s role is?
a) Initialize CPU registers
b) Device controllers
c) Load and start OS
d) All of these
Explanation: The bootstrap program initializes hardware minimally and loads the OS kernel.
30. Selecting and loading a task into memory is?
a) Single processing
b) Job scheduling
c) Single programming
d) Single-tasking
Explanation: Job scheduling (long-term scheduling) decides which jobs are admitted to the ready queue.
31. POST stands for?
a) Power On Self Test
b) Power Off Self Test
c) Power On/Off Self Test
d) None
Explanation: POST is a diagnostic testing sequence run by BIOS/UEFI at power-on.
32. BIOS means?
a) Basic Input Output System
b) Input Output Basic System
c) Booting Input Output System
d) None
Explanation: BIOS provides the lowest-level hardware abstraction and boot services.
33. Which verifies connected hardware like keyboard and monitor?
a) BIOS
b) POST
c) SIMPS
d) Master Boot Record
Explanation: Power-On Self-Test checks basic hardware functionality before booting.
34. Restarting a running computer with Ctrl + Alt + Del is?
a) Cold booting
b) Warm booting
c) Shut down
d) Logging off
Explanation: Warm boot restarts the OS without cutting power (faster than cold boot).
35. Core tasks of an OS include?
a) Processor management
b) User interface
c) Memory management
d) All of these
Explanation: Processor (process), memory, device, file, security, and user interface management are fundamental OS responsibilities.
36. The central part of an OS is?
a) Shell
b) Kernel
c) GUI
d) File system
Explanation: The kernel is the core component that manages system resources and hardware directly.
37. What OS type is for time-sensitive tasks?
a) Batch OS
b) Time-sharing OS
c) Real-time OS
d) Distributed OS
Explanation: Real-time OS (RTOS) is designed for applications where timing is critical (e.g., avionics, robotics).
38. Which is not an operating system?
a) Windows
b) Linux
c) Python
d) macOS
Explanation: Python is a high-level programming language, not an operating system.
39. The main goal of an OS is?
a) Manage hardware resources
b) Run applications
c) Compile programs
d) Edit text files
Explanation: Resource management (CPU, memory, I/O devices) is the primary responsibility of any OS.
40. An open-source OS is?
a) Windows
b) Linux
c) macOS
d) MS-DOS
Explanation: Linux kernel and many distributions are open-source under various free licenses.
41. Which memory technique employs paging?
a) Segmentation
b) Virtual memory
c) Contiguous allocation
d) Partitioning
Explanation: Paging is the main mechanism used to implement virtual memory in modern OS.
42. A deadlock occurs when?
a) Process in infinite loop
b) Processes wait indefinitely
c) Process executes without wait
d) Process releases resource early
Explanation: Deadlock is a situation where two or more processes are stuck waiting for each other to release resources.
43. Thrashing refers to?
a) High CPU use
b) Excessive page swapping
c) Boot failure
d) Infinite loop
Explanation: Thrashing occurs when the system spends more time swapping pages than executing processes.
44. Linux command to view processes?
a) dir
b) ps
c) cd
d) exit
Explanation: The ps command displays information about active processes.
45. Which is not a process state?
a) Running
b) Waiting
c) Ready
d) Compiled
Explanation: Compiled is a program development stage, not a runtime process state.
46. An operating system is?
a) Software managing hardware
b) Background program
c) Hardware component
d) Programming language
Explanation: OS is system software that controls hardware and provides services to application software.
47. Memory divided into fixed blocks uses?
a) Paging
b) Segmentation
c) Fragmentation
d) Swapping
Explanation: Paging divides both physical and virtual memory into fixed-size blocks called pages/frames.
48. Windows typically uses which file system?
a) EXT4
b) NTFS
c) HFS+
d) FAT32
Explanation: NTFS (New Technology File System) is the default and most feature-rich file system in modern Windows.
49. In UNIX, an orphan process is?
a) Terminated with table entry
b) Parent finished execution
c) No memory assigned
d) Running in kernel mode
Explanation: An orphan process continues running after its parent terminates; it is usually adopted by init (PID 1).
50. Which OS lacks multitasking support?
a) Windows XP
b) MS-DOS
c) Linux
d) macOS
Explanation: Original MS-DOS was single-tasking; only one program could run at a time.
