Operating System: Complete In‑Depth Notes for JKSSB, SBI PO & IBPS Exams (Home Academy)
An Operating System is the backbone of any computing device. It acts as an interface between the user and computer hardware, enabling users to interact with the system efficiently while ensuring optimal utilization of resources. For competitive examinations such as SBI PO, IBPS PO, IBPS Clerk, and other banking exams, the topic of Operating System is frequently asked in both objective and conceptual formats. Understanding its functions, structure, and technical working is essential to score well.
What is an Operating System
An Operating System, commonly abbreviated as OS, is system software that manages computer hardware, software resources, and provides common services for computer programs. It controls the execution of application programs and acts as a resource allocator. Without an operating system, a computer is just a collection of hardware components without coordination or usability.
In banking examinations, Operating System questions often test conceptual clarity rather than programming depth. Candidates are expected to understand how the OS manages memory, processes, files, and devices rather than internal coding details.
Objectives of an Operating System
The primary objective of an operating system is to make the computer system convenient to use. It ensures that hardware resources such as CPU, memory, storage, and input-output devices are used efficiently. Another important objective is to provide a stable and secure environment for application execution while preventing unauthorized access to system resources.
Functions of an Operating System
The operating system performs several critical functions that keep the computer system running smoothly. Process management is one of the most important functions. The OS creates, schedules, executes, and terminates processes. It ensures that multiple processes can run simultaneously without interfering with each other by using techniques such as multitasking and context switching.
Memory management is another vital function. The operating system keeps track of primary memory usage, allocates memory to processes when needed, and deallocates memory once the process finishes execution. It also handles virtual memory, allowing programs to use more memory than physically available by using secondary storage as an extension of RAM.
File system management allows the operating system to organize data efficiently. It manages files and directories, controls access permissions, and ensures data integrity. The OS decides how data is stored, retrieved, and protected on storage devices such as hard disks and SSDs.
Device management is handled through device drivers. The operating system communicates with hardware devices such as printers, keyboards, scanners, and monitors. It coordinates device usage and resolves conflicts when multiple processes request the same device simultaneously.
Security and protection are integral functions of an operating system. The OS ensures that unauthorized users do not access sensitive data. It implements authentication mechanisms such as passwords and access control lists. In modern systems, encryption and firewall support are also integrated at the OS level.
User interface management is another essential function. The operating system provides a user interface that can be command-line based, such as MS-DOS or UNIX shell, or graphical, such as Windows, Linux GUI, and macOS. This interface allows users to interact with the system easily.
Types of Operating Systems
Operating systems are classified based on their functionality and usage. A batch operating system executes jobs in batches without user interaction. A time-sharing operating system allows multiple users to use the computer simultaneously by allocating time slices to each user. A real-time operating system responds to inputs within a fixed time constraint and is widely used in medical systems, robotics, and embedded devices.
Distributed operating systems manage a group of independent computers and make them appear as a single system. Network operating systems provide services such as file sharing and printer access over a network. Mobile operating systems such as Android and iOS are specifically designed for smartphones and tablets.
Kernel and Its Role
The kernel is the core component of an operating system. It directly interacts with hardware and manages system resources. The kernel handles process scheduling, memory management, device communication, and system calls. In exams, questions are often asked about the kernel being the heart of the operating system.
Booting Process
Booting is the process of starting a computer and loading the operating system into memory. When the system is powered on, the BIOS or UEFI performs hardware checks and loads the bootloader. The bootloader then loads the operating system kernel into RAM. This concept is frequently tested in banking exams.
Important MCQs on Operating System (SBI PO & IBPS PYQs)
Which of the following is the main function of an operating system
A. Word processing
B. Resource management
C. Database management
D. Spreadsheet calculation
Correct Answer: BWhich part of the operating system interacts directly with the hardware
A. Shell
B. Compiler
C. Kernel
D. Application software
Correct Answer: CWhich operating system allows multiple users to use a computer system simultaneously
A. Batch operating system
B. Single-user operating system
C. Time-sharing operating system
D. Real-time operating system
Correct Answer: CVirtual memory is associated with which function of an operating system
A. File management
B. Memory management
C. Device management
D. Process management
Correct Answer: BWhich of the following is an example of a real-time operating system
A. Windows 10
B. Linux
C. Android
D. VxWorks
Correct Answer: DWhich operating system component is responsible for handling system calls
A. Application software
B. Kernel
C. Device driver
D. User interface
Correct Answer: BThe process of loading the operating system into main memory is called
A. Scheduling
B. Spooling
C. Booting
D. Paging
Correct Answer: CWhich of the following is not a function of an operating system
A. Memory allocation
B. Virus detection
C. File management
D. Process scheduling
Correct Answer: B
Additional SBI PO & IBPS Previous Year MCQs on Operating System
Which of the following operating systems was developed by AT&T Bell Labs
A. Windows
B. UNIX
C. DOS
D. Android
Correct Answer: BWhich scheduling algorithm is used in time-sharing operating systems
A. First Come First Serve
B. Shortest Job First
C. Round Robin
D. Priority Scheduling
Correct Answer: CWhich of the following memory is volatile in nature
A. ROM
B. Hard Disk
C. RAM
D. DVD
Correct Answer: CThe main purpose of paging in an operating system is to
A. Increase CPU speed
B. Reduce memory fragmentation
C. Improve file security
D. Control device access
Correct Answer: BWhich operating system is mostly used in embedded systems
A. Batch operating system
B. Real-time operating system
C. Distributed operating system
D. Network operating system
Correct Answer: BWhich of the following is an example of multitasking operating system
A. MS-DOS
B. Windows
C. BIOS
D. Firmware
Correct Answer: BWhich component of operating system is responsible for deadlock handling
A. File system
B. Memory manager
C. Process manager
D. Device manager
Correct Answer: CWhich of the following allows the operating system to run multiple programs simultaneously
A. Spooling
B. Multitasking
C. Multiprogramming
D. Booting
Correct Answer: CThe smallest unit of data processed by a computer is
A. Byte
B. Bit
C. Nibble
D. Word
Correct Answer: BWhich operating system feature ensures that one user does not interfere with another user’s data
A. Scheduling
B. Protection
C. Spooling
D. Buffering
Correct Answer: BWhich of the following is not a type of operating system
A. Batch OS
B. Time-sharing OS
C. Compiler OS
D. Real-time OS
Correct Answer: CWhich memory management technique allows execution of processes larger than main memory
A. Segmentation
B. Paging
C. Virtual memory
D. Swapping
Correct Answer: CWhich operating system is mainly designed for mobile devices
A. UNIX
B. Android
C. MS-DOS
D. Windows NT
Correct Answer: BWhich of the following terms refers to the time taken by the operating system to switch from one process to another
A. Turnaround time
B. Waiting time
C. Response time
D. Context switching
Correct Answer: DWhich operating system manages communication between user and hardware
A. Compiler
B. Assembler
C. Operating system
D. Interpreter
Correct Answer: CWhich of the following is responsible for controlling input and output devices
A. Kernel
B. Device drivers
C. Shell
D. Application software
Correct Answer: BWhich operating system function allocates CPU time to different processes
A. Memory management
B. File management
C. Process scheduling
D. Device management
Correct Answer: CWhich of the following is an example of network operating system
A. Windows Server
B. MS Paint
C. Android
D. MS Word
Correct Answer: AWhich operating system concept helps in improving CPU utilization
A. Multiprogramming
B. Booting
C. Spooling
D. Buffering
Correct Answer: AWhich of the following is the first program loaded when a computer starts
A. Application software
B. Operating system
C. BIOS
D. Compiler
Correct Answer: CWhich of the following is used to prevent unauthorized access to computer resources
A. Scheduling
B. Authentication
C. Buffering
D. Caching
Correct Answer: BWhich operating system is open-source in nature
A. Windows
B. macOS
C. Linux
D. DOS
Correct Answer: C
The Operating System remains one of the most scoring topics in computer awareness for SBI PO and IBPS examinations. Regular practice of previous year questions along with conceptual clarity ensures high accuracy. Home Academy strongly recommends focusing on operating system fundamentals, real-world examples, and PYQs to master this topic effectively.