Wednesday, November 12, 2025

EMRS Tier-I Syllabus Part-III: Basics of Operating System, Knowledge of ICT (Information & Communication Technology), PGT, TGT, Non Teaching Post, Exam 2025

📘 OPERATING SYSTEM – EXPERT NOTES (Highly Exam Focused)

1. Definition of OS

Operating System ek system software hai jo hardware aur user ke beech interface ka kaam karta hai.
It manages processes, memory, files, devices, security, and user interaction.

🧠 EXPERT NOTES – TOPIC WISE

2. Functions of Operating System

(A) Process Management

Process creation, scheduling, termination

Context switching

Deadlock handling

CPU scheduling algorithms:

FCFS

SJF

Priority

Round Robin

Multilevel Queue

(B) Memory Management

Allocation & deallocation

Contiguous memory allocation

Paging

Segmentation

Virtual memory (Demand Paging, Thrashing)

Page replacement: FIFO, LRU, Optimal

(C) File Management

Create, delete, read, write, update

File attributes

File allocation methods:

Sequential

Indexed

Linked

(D) Device Management

Device drivers

I/O management

Buffering, spooling

(E) Protection & Security

Authentication, authorization

Encryption

Access control lists (ACL)

(F) User Interface

Command Line Interface (CLI)

Graphical User Interface (GUI)

3. Types of Operating Systems

Batch OS – No user interaction, jobs in batches

Time Sharing OS – Multi-user, time slice based

Multiprogramming OS – Multiple programs in memory

Multitasking OS – Multiple tasks for a user

Real Time OS (RTOS) – Very fast, predictable

Distributed OS – Multiple computers acting as one

Network OS – Manages network resources

4. System Calls

Used by user programs to request OS services.
Types: Process control, File management, Device management, Information maintenance, Communication.

5. Memory Concepts

Internal fragmentation
External fragmentation
Swapping
Paging (frame/page size)
Segments
Page Fault
Working Set
TLB (Translation Lookaside Buffer)

6. Scheduling Concepts

CPU Burst + I/O Burst

Preemptive vs Non-preemptive

Turnaround time, Waiting time, Response time

7. Deadlock

Occurs when processes wait forever for resources.

Conditions (Coffman)

Mutual exclusion

Hold and wait

No preemption

Circular wait

Handling Techniques

Prevention

Avoidance (Banker’s Algorithm)

Detection & Recovery

✅ 50 MCQs on Operating System (English + Hindi)

1. Operating System is a –

A. Hardware
B. Application software
C. System software
D. Utility

Correct Answer: C
Hindi Explanation: OS system software hota hai jo hardware par control rakhta hai.

2. Which of the following is NOT an OS?

A. Linux
B. Windows
C. Oracle
D. Android

Correct Answer: C
Hindi: Oracle ek DBMS hai, OS nahi.

3. OS that responds immediately is called –

A. Batch OS
B. Real-time OS
C. Time sharing OS
D. Distributed OS

Answer: B
Hindi: RTOS turant response deta hai.

4. CPU scheduling is part of –

A. Process management
B. Memory management
C. File management
D. Security

Answer: A

5. Round Robin scheduling is best for –

A. Batch jobs
B. Interactive systems
C. Real-time systems
D. Multiprocessing

Answer: B

(Hindi: Round Robin interactive systems ke liye sabse theek.)

6. Page fault occurs when –

A. Page is in memory
B. Page is not in memory
C. Disk is full
D. RAM is full

Answer: B

7. Thrashing occurs due to –

A. High CPU usage
B. Excessive paging
C. Low RAM
D. Fragmentation

Answer: B

8. Which is NOT a deadlock condition?

A. Circular wait
B. Mutual exclusion
C. Swapping
D. Hold and wait

Answer: C

9. FCFS stands for –

A. First Come First Serve
B. First Check First Serve
C. Fast Come Fast Serve
D. File Control File System

Answer: A

10. Virtual memory is –

A. Cache memory
B. RAM + Disk
C. ROM
D. CPU register

Answer: B

11. Page replacement algorithm –

A. FIFO
B. LRU
C. Optimal
D. All of these

Answer: D

12. Who developed Linux?

A. Charles Babbage
B. Steve Jobs
C. Linus Torvalds
D. Bill Gates

Answer: C

13. Which OS uses a shell?

A. Windows
B. Unix
C. Android
D. iOS

Answer: B

14. Fragmentation occurs in –

A. Paging
B. Segmentation
C. Contiguous allocation
D. None

Answer: C

15. TLB stands for –

A. Translation Lookaside Buffer
B. Temporary Load Buffer
C. Terminal Link Buffer
D. Transfer Load Block

Answer: A

16. Which of the following is NOT a type of OS?

A. Batch
B. Time Sharing
C. Compiler
D. Real Time
Answer: C
Hindi: Compiler ek language translator hai, OS nahi.

17. Which OS is used in mobile phones?

A. Android
B. MS-DOS
C. UNIX
D. Windows 98
Answer: A

18. GUI stands for –

A. General User Interface
B. Graphical User Interface
C. Group User Interface
D. Graphic Utility Interaction
Answer: B

19. MS-DOS is a –

A. GUI OS
B. Single-user OS
C. Multi-user OS
D. Real-time OS
Answer: B

20. The kernel is –

A. Part of RAM
B. Core part of OS
C. Hardware
D. Application
Answer: B

21. Process in execution is known as –

A. Thread
B. Job
C. Task
D. Program
Answer: C

22. Which scheduling method causes starvation?

A. FCFS
B. Round Robin
C. Priority
D. SJF
Answer: C
Hindi: Priority scheduling me low-priority process wait karte rehte hain.

23. The smallest unit of memory management is –

A. Frame/Page
B. Segment
C. Byte
D. File
Answer: A

24. Which of these is preemptive scheduling?

A. FCFS
B. SJF
C. SRTF
D. Priority (Non-preemptive)
Answer: C

25. Banker's Algorithm is for –

A. Scheduling
B. Deadlock avoidance
C. Memory allocation
D. File allocation
Answer: B

26. Spooling stands for –

A. Simultaneous Peripheral Operation On-Line
B. Sequential Peripheral Operation On-Line
C. Spontaneous Operation Layer
D. None
Answer: A

27. Semaphore is used to –

A. Manage memory
B. Control concurrency
C. Manage I/O
D. Detect virus
Answer: B

28. Which is NOT a file allocation method?

A. Sequential
B. Indexed
C. Linked
D. Spooling
Answer: D

29. Which OS launched first among these?

A. Windows 95
B. Windows XP
C. Windows 7
D. Windows 10
Answer: A

30. UNIX is written in –

A. Java
B. Assembly
C. C
D. Python
Answer: C

31. Which is NOT a feature of OS?

A. Memory management
B. File management
C. CPU management
D. Compilation
Answer: D

32. Interrupt is generated by –

A. CPU
B. I/O device
C. RAM
D. Cache
Answer: B

33. The ready queue stores –

A. Completed processes
B. Blocked processes
C. Processes waiting for CPU
D. Processes doing I/O
Answer: C

34. Multithreading improves –

A. Speed
B. Security
C. File allocation
D. Voltage
Answer: A

35. OS X is developed by –

A. Microsoft
B. Apple
C. IBM
D. Google
Answer: B

36. What is the primary purpose of OS?

A. Entertainment
B. Manage hardware
C. Create websites
D. Write programs
Answer: B

37. A process may be in which state?

A. Ready
B. Running
C. Blocked
D. All of these
Answer: D

38. Which is NOT a memory allocation technique?

A. Contiguous
B. Paging
C. Spooling
D. Segmentation
Answer: C

39. Context switching refers to –

A. Switching memory
B. Switching CPU between processes
C. Switching monitor
D. Switching hard disk
Answer: B

40. Linux is –

A. Open-source
B. Closed-source
C. Proprietary
D. Paid-only
Answer: A

41. Which system call creates a process?

A. fork()
B. exec()
C. wait()
D. kill()
Answer: A

42. Booting means –

A. Shutdown process
B. Starting the OS
C. Installing apps
D. Formatting disk
Answer: B

43. OS that handles multiple processors –

A. Single-user OS
B. Multitasking OS
C. Multiprocessing OS
D. Real-time OS
Answer: C

44. Disk scheduling algorithm –

A. FCFS
B. SSTF
C. SCAN
D. All of these
Answer: D

45. IPC means –

A. Inter Process Communication
B. Internal Processor Control
C. International Program Code
D. Internet Process Control
Answer: A

46. The shell is a –

A. Hardware
B. Command interpreter
C. Compiler
D. CPU
Answer: B

47. Windows uses which file system?

A. ext4
B. NTFS
C. FAT32
D. Both B & C
Answer: D

48. Which OS is MOST secure?

A. Windows
B. Linux
C. MS-DOS
D. Android
Answer: B

49. Which OS uses the HFS+ file system?

A. Windows
B. Linux
C. MacOS
D. Android
Answer: C

50. Boot loader is stored in –

A. RAM
B. ROM
C. Hard disk (MBR)
D. Cache
Answer: C

30 PYQs (WITH OPTIONS) – Operating System (EMRS/KVS/NVS Level)

PYQ 1. MS-DOS is a –

A. Single-user, single-tasking OS
B. Multiuser OS
C. Real-time OS
D. Network OS
✔ Answer: A
Hindi: MS-DOS ek single-user aur single-tasking operating system hai।

PYQ 2. Which OS introduced the Start Menu?

A. Windows XP
B. Windows 7
C. Windows 95
D. Windows Vista
✔ Answer: C

PYQ 3. Deadlock occurs due to –

A. Mutual exclusion
B. Hold & wait
C. No preemption
D. Circular wait
✔ Answer: D
(Deadlock ke 4 conditions me se sabse important: Circular wait)

PYQ 4. Virtual memory increases –

A. CPU speed
B. Effective memory size
C. Disk fragmentation
D. File size
✔ Answer: B

PYQ 5. Deadlock avoidance uses –

A. FCFS
B. Banker’s Algorithm
C. FIFO
D. LRU
✔ Answer: B

PYQ 6. Thrashing occurs due to –

A. Too little memory
B. Too much CPU
C. Too many printers
D. Slow hard disk
✔ Answer: A

PYQ 7. FCFS scheduling is –

A. Preemptive
B. Non-preemptive
C. Real-time
D. Hybrid
✔ Answer: B

PYQ 8. UNIX is a –

A. Single-user OS
B. Multiuser, multitasking OS
C. Real-time OS
D. Batch OS
✔ Answer: B

PYQ 9. Windows OS is developed by –

A. Apple
B. Microsoft
C. IBM
D. Google
✔ Answer: B

PYQ 10. PCB stores –

A. File allocation table
B. CPU scheduling table
C. Process information
D. Virtual memory table
✔ Answer: C

PYQ 11. SJF stands for –

A. Small Job First
B. Shortest Job First
C. Simple Job Function
D. Sorted Job Framework
✔ Answer: B

PYQ 12. Fastest memory is –

A. Hard disk
B. RAM
C. Cache
D. CD-ROM
✔ Answer: C

PYQ 13. Kernel loads during –

A. Shutdown
B. Installation
C. Booting
D. Formatting
✔ Answer: C

PYQ 14. System call to terminate process –

A. end()
B. close()
C. exit()
D. stop()
✔ Answer: C

PYQ 15. LRU algorithm replaces –

A. Largest page
B. Smallest page
C. Recently used page
D. Least recently used page
✔ Answer: D

PYQ 16. Open-source OS is –

A. Windows
B. Linux
C. MacOS
D. Android
✔ Answer: B

PYQ 17. Device driver is –

A. Hardware device
B. OS feature
C. Software controlling hardware
D. Network device
✔ Answer: C

PYQ 18. Round Robin is used in –

A. Real-time system
B. Time-sharing OS
C. Batch processing
D. Single-tasking OS
✔ Answer: B

PYQ 19. Interrupt priority is managed by –

A. Hard disk
B. CPU
C. ROM
D. RAM
✔ Answer: B

PYQ 20. Internal fragmentation occurs in –

A. Paging
B. Segmentation
C. Fixed partition allocation
D. Demand paging
✔ Answer: C

PYQ 21. IPC includes –

A. Pipes
B. Message queues
C. Shared memory
D. All of the above
✔ Answer: D

PYQ 22. Which is a real-time OS?

A. Windows
B. Android
C. VxWorks
D. MS-DOS
✔ Answer: C

PYQ 23. Disk scheduling with minimum seek time –

A. FCFS
B. SSTF
C. SCAN
D. C-SCAN
✔ Answer: B

PYQ 24. Scheduler which selects next process for CPU –

A. Long-term scheduler
B. Medium-term scheduler
C. CPU scheduler
D. Queue scheduler
✔ Answer: C

PYQ 25. Which OS is developed by Google?

A. Windows
B. iOS
C. Linux
D. Android
✔ Answer: D

PYQ 26. Ready queue stores –

A. Processes doing I/O
B. Processes terminated
C. Processes waiting for CPU
D. All processes
✔ Answer: C

PYQ 27. Segmentation divides memory into –

A. Pages
B. Blocks
C. Logical segments
D. Clusters
✔ Answer: C

PYQ 28. CLI example –

A. Windows 10
B. Chrome
C. Command Prompt
D. File Explorer
✔ Answer: C

PYQ 29. Cache memory works on –

A. Hashing
B. Temporal & spatial locality
C. Compression
D. Paging
✔ Answer: B

PYQ 30. A process waiting for I/O is in –

A. Ready state
B. Running state
C. Blocked state
D. Suspended state

✔ Answer: C

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