Computer Notes in Hindi — MP Police SI Prelims 2026 (113 Official PYQs)

📊 2025 paper ka analysis (12 shifts × 10 = 120 Computer questions): Sabse zyada sawal Internet/Browser/URL/IP (≈20), Windows/OS (≈16), Cyber Security (≈10), Backup & Cloud Storage (≈8), Software types (≈8), Memory/Storage (≈7), Excel (≈7) se aaye. Level: aasaan se medium, kuch "applied" (practical) sawal. Isliye har topic me concept + practical example diya hai — ratne ke saath samajhna bhi zaroori hai.

📑 इस पेज पर उपलब्ध टॉपिक्स (Jump to Topic):

1. Computer Basics (मूल बातें) 2. History, Fathers & Generations 3. CPU, Motherboard & Ports 4. Memory & Storage (मेमोरी) 5. Input / Output Devices 6. Software & Languages 7. Operating System & Windows 8. MS Word 9. MS Excel 10. MS PowerPoint 11. Internet, WWW, Browser, URL, IP, DNS 12. Email 13. Networking (नेटवर्किंग) 14. Protocols & Ports 15. Cyber Security (साइबर सुरक्षा) 16. Backup & Cloud Storage 17. Cyber Crime & IT Act 2000 18. Number System (संख्या पद्धति) 19. Important Abbreviations 20. Latest Tech, UPI & e-Governance

📌 1. कंप्यूटर की मूल बातें (Computer Basics) (6 min read)

1.1 Computer kya hai?

Computer = ek electronic machine jo data (आँकड़े) ko input ke roop me leti hai, instructions (program) ke hisaab se process karti hai, aur information (सूचना) output deti hai. Word "compute" = ganana karna.
Computer ko "Data Processor" bhi kehte hain, kyunki ye data ko store, process aur jab chahe retrieve (वापस प्राप्त) kar sakta hai.
Data = raw facts (कच्चे तथ्य), jaise marks 45, 67. Information = processed, meaningful data, jaise "average 56".
IPO Cycle: Input → Process → Output (+ Storage). Data processing ki 3 sub-activities: (1) input data capture karna, (2) data manipulate karna, (3) output results manage karna.
GIGO = Garbage In, Garbage Out — galat input ya kharab program → galat output. Computer khud galti nahi karta; galti input/program ki hoti hai.

1.2 Computer ke components

Part	Matlab	Example
Hardware	Physical parts jinhe chhoo sakte hain	Keyboard, CPU, Hard disk, Floppy drive, Monitor
Software	Programs / instructions ka set (chhoo nahi sakte)	Windows, MS Word, Compiler, Antivirus
Firmware	Hardware (ROM chip) me permanently likha software	BIOS
Liveware / Humanware / Peopleware	Computer use karne wale log (users)	Operator, programmer

⚠️ Hardware akele kuch nahi kar sakta — use software instructions chahiye. Aur software ko chalne ke liye hardware chahiye.

1.3 Computer ki visheshtayen (Characteristics)

Characteristic	Matlab
Speed (गति)	Lakhon-karodon operations per second; time microsecond (10⁻⁶), nanosecond (10⁻⁹), picosecond (10⁻¹²) me naapa jata hai
Accuracy (शुद्धता)	Sahi input par hamesha sahi result (errors = GIGO)
Diligence (अविरामता / लगन)	Bina thake, bina aaram, lagatar kaam; monotony, tiredness, lack of concentration se mukt
Versatility (बहुमुखी प्रतिभा)	Ek hi computer banking, gaming, scientific — alag-alag kaam kar sakta hai
Storage / Memory	Bahut sara data store karke kabhi bhi recall kar sakta hai
Reliability	Bharosemand, lambe samay tak same result

Seemayen (Limitations): No I.Q. — computer khud decision nahi le sakta, use batana padta hai kya aur kis kram (sequence) me karna hai. No Feelings — bhavnaon/instinct ke aadhar par judgment nahi le sakta.

1.4 Computer ke prakar (Types)

Aadhar	Types
Kaam karne ka tarika	Analog (continuous data — thermometer, speedometer), Digital (discrete 0/1 — PC, laptop), Hybrid (dono ka mel — hospital ICU monitoring)
Size / Power	Micro (PC, laptop, desktop) → Mini (medium organisations) → Mainframe (bank, railway reservation; hazaron users terminals se) → Supercomputer (sabse tez; mausam forecast, nuclear research; speed FLOPS me)
Purpose	General purpose (PC) vs Special purpose (ATM, washing machine controller)

Dumb Terminal: Mainframe se juda keyboard + monitor jiske paas apni processing ya storage nahi hoti — sab kaam mainframe karta hai. (Smart terminal me thodi processing hoti hai.)
Computer Simulation: Real-world system ko ek mathematical model ke roop me computer par chalana (jaise flight simulator, mausam model).
Applications: CAD (Computer-Aided Design) aur CAM — manufacturing/engineering design me; e-governance, banking, healthcare, education, defence.

⚠️ Exam Traps:

"Bina aaram lagatar kaam" = Diligence (Speed nahi). "Alag-alag kaam" = Versatility.
"No IQ" = khud decision nahi le sakta. "No feelings" = bhavna se judgment nahi. Dono alag options hote hain.
Compiler hardware nahi, software hai.
GIGO ka full form "Garbage In Garbage Out" — GIGA/GOGA jaise distractors se bachen.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. विशेषताएँ "No I.Q." क्या दर्शाती हैं? / What do the characteristics "No I.Q." represent? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) Feelings/instincts ke aadhar par judgment nahi le sakta

(B) Khud decision nahi le sakta; batana padta hai kya aur kis kram me karna hai

(C) Bahut sari information store karke recall kar sakta hai

(D) Monotony, thakan se mukt hai

सही उत्तर: (B)
No IQ = computer "dumb" machine hai, apna dimaag nahi lagata. (A) "No Feelings" ki paribhasha hai, (C) Storage, (D) Diligence.

Q2. निम्नलिखित में से कौन-सा कथन सही है? (Data processing) / Which statement is true? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) Data processing me 3 sub-activities: input capture, data manipulate, output results manage

(B) 2 sub-activities: input capture aur manipulate

(C) 4 sub-activities: capture, calculate, manipulate, output

(D) None of the above

सही उत्तर: (A)
Standard textbook definition: data processing = capturing input data + manipulating data + managing output results (teen).

Q3. Software, data और users के विवरण के अनुसार कौन-सा कथन सही नहीं है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) Program = instructions ka set jo computer ki samajh wali language me likha ho

(B) Hardware akele bina software instructions ke kaam kar sakta hai

(C) Data raw facts hain jinhe process karke meaningful information banti hai

(D) Users ko skinware, liveware, humanware, peopleware bhi kehte hain

सही उत्तर: (B)
Hardware bina software ke bekaar hai — ye kathan galat hai, baaki teeno sahi.

Q4. मेनफ्रेम सिस्टम में डम्ब टर्मिनल की मुख्य विशेषता क्या है? / Main characteristic of a dumb terminal? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) Data store kar sakta hai par process nahi

(B) Na data store kar sakta hai, na khud processing

(C) Apni storage aur processing capability hai

(D) Process kar sakta hai par output display nahi

सही उत्तर: (B)
Dumb terminal sirf input bhejta aur output dikhata hai; storage/processing mainframe karta hai.

Q5. कौन-सी खासियत कंप्यूटर को banking, gaming और scientific कामों के बीच switch करने देती है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) Isolation

(B) Versatility (बहुमुखी प्रतिभा)

(C) Humanness

(D) Infallibility

सही उत्तर: (B) Versatility
Ek machine, anek prakar ke kaam = versatility.

Q6. कौन-सा अनुप्रयोग क्षेत्र CAD (Computer-Aided Design) के लिए कंप्यूटर का उपयोग करता है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) Manufacturing (उत्पादन)

(B) Education

(C) Defense

(D) Healthcare

सही उत्तर: (A) Manufacturing
CAD/CAM products aur machine parts ke design-manufacturing me use hote hain (AutoCAD jaisa software).

Q7. जो कंप्यूटर बिना आराम किए लगातार काम करते हैं, वे किस विशेषता को दर्शाते हैं? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) Emotion

(B) Diligence (अविरामता)

(C) Transparency

(D) Randomness

सही उत्तर: (B) Diligence

Q8. कंप्यूटर को अक्सर ____ कहा जाता है, क्योंकि यह डेटा को जब चाहें संग्रहीत, संसाधित और पुनः प्राप्त कर सकता है। MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) Data analyzer

(B) Data processor

(C) Data compiler

(D) Data converter

सही उत्तर: (B) Data processor

Q9. निम्नलिखित में से कौन-सा हार्डवेयर का उदाहरण नहीं है? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) Keyboard

(B) Hard disk drive

(C) Floppy disk drive

(D) Compiler

सही उत्तर: (D) Compiler
Compiler ek software (language translator) hai.

Q10. कंप्यूटर सिमुलेशन का मुख्य उद्देश्य क्या है? / Primary purpose of computer simulation? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) Real-world experiments ko physically karna

(B) Real-world system ko represent karne wala mathematical model chalana

(C) Analytical solutions ko manual calculation se badalna

(D) Sirf graphical output visualize karna

सही उत्तर: (B)

Q11. गलत इनपुट डेटा या अविश्वसनीय प्रोग्रामों के कारण होने वाली त्रुटियों को ____ कहा जाता है। MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) garbage-in-garbage-out (GIGO)

(B) garbage-in-garbage-add (GIGA)

(C) garbage-out-garbage-add (GOGA)

(D) None of the above

सही उत्तर: (A) GIGO

✍️ Practice MCQs (self-made — PYQ nahi)

P1. Thermometer aur speedometer kis prakar ke computing device ke udaharan hain? Practice MCQ

(A) Digital

(B) Analog

(C) Hybrid

(D) Mainframe

उत्तर: (B) Analog — continuous (lagatar badalne wali) quantity naapte hain.

P2. Mausam poorvanuman (weather forecasting) jaise bahut bade calculations ke liye kaunsa computer use hota hai? Practice MCQ

(A) Microcomputer

(B) Minicomputer

(C) Supercomputer

(D) Laptop

उत्तर: (C) Supercomputer

📌 2. इतिहास, जनक एवं पीढ़ियाँ (History, Fathers & Generations) (7 min read)

2.1 Timeline — ganana yantra se computer tak

Device / Machine	Kisne / Kab	Yaad rakhne wali baat
Abacus (गिनतारा)	Prachin kaal (China/Mesopotamia)	Sabse pehla ganana yantra; motiyon (beads) se jod-ghata
Napier's Bones	John Napier, 1617	Guna (multiplication) ke liye chhadiyan
Pascaline	Blaise Pascal, 1642	Pehla mechanical adding machine (jod-ghata)
Stepped Reckoner	Leibniz, 1673	Guna-bhag bhi kar sakta tha
Jacquard Loom	Joseph Marie Jacquard, 1804	Punch card se kapde ka design — punch card idea yahin se
Difference Engine (1822) & Analytical Engine (1830s)	Charles Babbage	Analytical Engine me Mill (≈CPU), Store (≈Memory), punch card input — aadhunik computer ka aadhar. Isliye Babbage = "Father of Computer"
—	Ada Lovelace	Analytical Engine ke liye program likha — duniya ki pehli programmer
Tabulating Machine	Herman Hollerith, 1890 (US census)	Punch card se data processing; unki company aage chalkar IBM bani
Mark I (ASCC)	Howard Aiken + IBM; 1937–44 (1937 me design, 1944 me Harvard ko mila)	Electromechanical computer
ENIAC	J. Presper Eckert & John Mauchly; 1946 me public	Pehla general-purpose electronic digital computer; lagbhag 18,000 vacuum tubes
EDSAC	Maurice Wilkes, 1949 (Cambridge)	Pehla vyavaharik stored-program computer
UNIVAC I	Eckert & Mauchly, 1951	Pehla commercial computer (USA)

Von Neumann Architecture: John von Neumann ka stored-program concept — program aur data dono memory me store. Aaj ke lagbhag sabhi computer isi par.

2.2 Computer ki peedhiyan (Generations)

Generation	Technology	Features / Examples
1st (≈1940–1956)	Vacuum Tube	Bahut bade, garam, zyada bijli; machine language; punch cards; ENIAC, EDVAC, UNIVAC I
2nd (≈1956–1963)	Transistor (1947, Bell Labs)	Chhote, tez; assembly language, FORTRAN/COBOL shuru; IBM 1401
3rd (≈1964–1971)	IC (Integrated Circuit) — Jack Kilby, 1958	Keyboard-monitor, operating system, multiprogramming; IBM System/360
4th (≈1971–ab tak)	Microprocessor (VLSI) — Intel 4004 (1971) pehla microprocessor	Personal Computer (IBM PC 1981), GUI, internet, laptop
5th (vartaman–bhavishya)	AI (Artificial Intelligence), ULSI, parallel processing	Natural language, robotics, expert systems, quantum computing research

Note: alag-alag books me years 1–2 saal aage-peeche hote hain; exam me technology ka kram (Vacuum tube → Transistor → IC → Microprocessor → AI) sabse zaroori hai.

2.3 "Father of ..." (जनक) — sabse zyada poochhe jaane wale

Field	Father / Janak	Field	Father / Janak
Computer	Charles Babbage	Pehli programmer	Ada Lovelace
Modern Computer Science (Turing Machine, Turing Test)	Alan Turing	Artificial Intelligence (term 1956)	John McCarthy
Internet (TCP/IP)	Vint Cerf & Bob Kahn	World Wide Web (1989)	Tim Berners-Lee
Email (1971, @ ka use)	Ray Tomlinson	Computer Mouse	Douglas Engelbart
QWERTY keyboard	Christopher Latham Sholes	Stored program concept	John von Neumann
Linux (1991)	Linus Torvalds	C language (1972) / UNIX	Dennis Ritchie (UNIX: Ken Thompson ke saath)
Java	James Gosling	Python	Guido van Rossum
Indian Supercomputer (PARAM)	Vijay Bhatkar	Indian IT industry	F. C. Kohli
Hotmail (co-founder)	Sabeer Bhatia	USB (co-inventor, Intel)	Ajay Bhatt

2.4 India me computer

HEC-2M — India me install hone wala pehla electronic digital computer; Indian Statistical Institute (ISI), Kolkata, 1956 (Prof. P.C. Mahalanobis ki pahal). Ye British-built tha.
TIFRAC — India me hi design aur bana pehla (indigenous) digital computer; TIFR Mumbai; 1960 me formally commission hua (naam Pandit Nehru ne diya).
PARAM 8000 — India ka pehla swadeshi supercomputer (1991), C-DAC, Pune ne banaya. PARAM = "Parallel Machine" / Sanskrit me "param" (sarvochch).

⚠️ Exam Traps:

Father of Computer = Babbage; father of modern computer science = Turing; father of AI = McCarthy.
Internet ≠ WWW: Internet ke janak Vint Cerf; WWW ke Tim Berners-Lee.
1st gen = vacuum tube, 2nd = transistor, 3rd = IC, 4th = microprocessor. "IC" aur "microprocessor" ko ulta na karein.
Mark I (1944) electromechanical tha; ENIAC pehla fully electronic general-purpose.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. मार्क I कंप्यूटर किस वर्ष बनाया गया था? / In which year was the Mark I computer built? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) 1937-44

(B) 1947-48

(C) 1837-44

(D) 1847-49

सही उत्तर: (A) 1937-44
Howard Aiken ne 1937 me proposal/design diya; IBM ne banaya aur 1944 me Harvard ko diya.

✍️ Practice MCQs (self-made — PYQ nahi)

P1. Transistor ka prayog kis peedhi ke computers me hua? Practice MCQ

(A) Pehli

(B) Doosri

(C) Teesri

(D) Chauthi

उत्तर: (B) Doosri (2nd)

P2. Duniya ki pehli computer programmer kise mana jata hai? Practice MCQ

(A) Grace Hopper

(B) Ada Lovelace

(C) Marie Curie

(D) Alan Turing

उत्तर: (B) Ada Lovelace

P3. India ka pehla swadeshi supercomputer PARAM 8000 kis sanstha ne banaya? Practice MCQ

(A) ISRO

(B) BARC

(C) C-DAC

(D) DRDO

उत्तर: (C) C-DAC (Pune)

📌 3. CPU, Motherboard एवं Ports (Hardware) (6 min read)

3.1 CPU (Central Processing Unit) — "Computer ka dimaag (Brain)"

CPU = ALU + CU + Registers (aur saath me cache memory).

Part	Kaam
ALU (Arithmetic Logic Unit)	Saari ganana (+ − × ÷) aur logical kaam (AND, OR, NOT, tulna: >, <, =)
CU (Control Unit)	Poore computer ko control/coordinate karta hai; instruction fetch → decode → execute karwata hai. Khud data process nahi karta. "Computer ka manager/traffic police"
Registers	CPU ke andar sabse tez aur sabse chhoti memory (Accumulator, Program Counter, Instruction Register, MAR, MDR)

Machine cycle: Fetch → Decode → Execute → Store.
Clock speed Hertz me — aaj GHz (gigahertz) me. Multi-core = ek chip me kai processing cores (dual-core, quad-core).
Microprocessor = poora CPU ek chip par. Pehla: Intel 4004 (1971). Companies: Intel, AMD; mobile me Qualcomm Snapdragon, MediaTek, Apple.
GPU (Graphics Processing Unit) — graphics/video/AI ke liye alag processor.

3.2 Motherboard aur cabinet ke parts

Motherboard = main circuit board (PCB); isme CPU socket, RAM slots, chipset, BIOS chip, expansion slots (PCIe), CMOS battery (BIOS settings aur ghadi chalu rakhti hai).
SMPS (Switched-Mode Power Supply) — AC bijli ko DC me badal kar parts ko deta hai. UPS = bijli jaane par backup.
Bus = data le jaane wale raaste: Data bus (data), Address bus (memory location ka pata), Control bus (control signals).

3.3 Ports aur Connectors (2025 paper me poochhe gaye)

Port / Connector	Use
RJ45	Computer ko network (LAN/Ethernet) se jodna
RJ11	Telephone line / DSL modem
USB (Universal Serial Bus)	Pen drive, mouse, printer; plug-and-play, hot-swap. Type-A, Type-B, Type-C (ulta-seedha dono taraf lagta hai)
HDMI	Digital audio + video ek hi cable me (TV, projector). Type A (standard), Type C (Mini HDMI), Type D (Micro HDMI)
VGA	Purana analog video port (15-pin) — monitor/projector
FireWire (IEEE 1394)	High-speed bus — mukhya roop se video cameras aur external hard drives
PS/2	Purane keyboard (purple) aur mouse (green)
Serial (COM) / Parallel (LPT)	Purane modem / printer
SATA	Andar ki hard disk / SSD motherboard se jodna

⚠️ Exam Traps:

Calculation aur comparison (logic) dono ALU karta hai; CU sirf control karta hai.
Network cable = RJ45; phone cable = RJ11. VGA/HDMI = display, PS/2 = keyboard/mouse.
CPU ke andar sabse tez memory = Register (cache nahi).

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. कंप्यूटर को नेटवर्क से जोड़ने के लिए कौन-सा कनेक्टर उपयोग किया जाता है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) VGA Connector

(B) FireWire

(C) RJ45 Connector

(D) PS/2

सही उत्तर: (C) RJ45
Ethernet (LAN) cable ke dono sire par RJ45 connector hota hai.

Q2. ____ एक अन्य बस है, जिसका उपयोग आजकल मुख्य रूप से वीडियो कैमरों और बाहरी हार्ड ड्राइव्स के लिए किया जाता है। MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) FireWire

(B) USB Port

(C) SCSI Port

(D) PS/2

सही उत्तर: (A) FireWire
FireWire (IEEE 1394) ko textbook me "video cameras aur external hard drives" wali bus bataya gaya hai.

✍️ Practice MCQs (self-made — PYQ nahi)

P1. CPU ka kaunsa bhaag do sankhyaon ki tulna (comparison) karta hai? Practice MCQ

(A) CU

(B) ALU

(C) RAM

(D) Register

उत्तर: (B) ALU — logical/comparison operations bhi ALU me.

P2. Kaunsa port ek hi cable me digital audio aur video dono bhejta hai? Practice MCQ

(A) VGA

(B) PS/2

(C) HDMI

(D) RJ11

उत्तर: (C) HDMI

📌 4. मेमोरी एवं स्टोरेज (Memory & Storage) (8 min read)

4.1 Memory ki hierarchy (tez → dheema)

Registers → Cache → RAM (main memory) → SSD → Hard Disk → Optical disc / Tape
Upar jaate hain to: speed ↑, keemat per byte ↑, capacity ↓. Neeche aate hain to: sasta, bada, dheema.

4.2 Primary vs Secondary memory

Primary (Main) Memory	Secondary (Auxiliary) Memory
CPU seedha access karta hai	CPU seedha nahi; pehle RAM me load hota hai
Tez, mehngi, kam capacity	Dheemi, sasti, bahut zyada capacity
RAM (volatile) + ROM	Hard disk, SSD, pen drive, CD/DVD, memory card, tape
—	Kyun chahiye? Primary storage ki seemit capacity aur volatility (bijli jaate hi data mitna) ki kami poori karne ke liye

4.3 RAM aur ROM

RAM (Random Access Memory)	ROM (Read Only Memory)
Volatile (अस्थायी) — bijli band = data khatam	Non-volatile (स्थायी)
Read + Write dono	Mukhya roop se sirf Read
Chal rahe programs/data rakhti hai	BIOS/firmware, booting instructions

SRAM (Static RAM): flip-flops se bani; refresh ki zaroorat nahi; bahut tez, mehngi → cache memory me use.
DRAM (Dynamic RAM): capacitors se bani; charge leak hota hai isliye refresh circuit se lagatar padh-kar dobara likhna (refresh) padta hai; sasti → main memory. SDRAM, DDR4, DDR5 isi ke roop.
ROM ke prakar: PROM (ek baar program), EPROM (UV light se erase), EEPROM (electrically erase), Flash memory (EEPROM ka tez roop — pen drive, SSD, memory card).

4.4 Cache aur Virtual memory

Cache memory: CPU aur RAM ke beech ki bahut tez (SRAM) memory; baar-baar use hone wala data rakhti hai. L1 cache = CPU core ke sabse paas, sabse tez, sabse chhoti; phir L2, phir L3 (bada, cores ke beech shared).
Virtual memory: RAM kam padne par hard disk/SSD ka kuch hissa RAM ki tarah use (Windows me "paging file").

4.5 Secondary storage devices

Type	Examples	Key facts
Magnetic	Hard Disk (HDD), floppy, magnetic tape	Magnetic disk (HDD) = sabse zyada use hone wala secondary storage (paramparik roop se). Tape = sequential access (backup ke liye)
Optical	CD, DVD, Blu-ray	Laser se padhi jaati hai; data pits aur lands ke roop me
Solid-state / Flash	SSD, pen drive, memory card	Koi moving part nahi; HDD se kai guna tez

Hard disk ki banawat: ghoomti platters → gol raaste tracks → tracks ke tukde sectors. Ek sector me paramparik roop se 512 bytes (naye "Advanced Format" disks me 4096 bytes). Ek jaise tracks ka samooh = cylinder. Read/write head data padhta/likhta hai. Speed RPM me (jaise 5400, 7200 RPM).
Access time = seek time (head ko track tak le jaana) + rotational latency (sector ka head ke neeche aana).
Capacity (lagbhag): Floppy 3.5" = 1.44 MB; CD = 700 MB; DVD = 4.7 GB (single layer), 8.5 GB (dual layer); Blu-ray = 25 GB (single layer, blue-violet laser).
CD-ROM = sirf padh sakte hain; CD-R = ek baar likho (WORM — Write Once Read Many); CD-RW = baar-baar likho-mitao.
DVD-ROM bhi optical storage hai (digital video ya computer data), CD jitna hi size (12 cm) par zyada capacity.

4.6 Memory ki ikaiyan (Units)

Unit	Barabar	Unit	Barabar
1 Bit	0 ya 1 (Binary digit) — sabse chhoti ikai	1 GB (Gigabyte)	1024 MB
1 Nibble	4 bits	1 TB (Terabyte)	1024 GB
1 Byte	8 bits (ek character)	1 PB (Petabyte)	1024 TB
1 KB (Kilobyte)	1024 bytes (2¹⁰)	1 EB (Exabyte)	1024 PB
1 MB (Megabyte)	1024 KB	1 ZB → 1 YB	Zettabyte → Yottabyte

Kram yaad karein: Bit → Nibble → Byte → KB → MB → GB → TB → PB → EB → ZB → YB. (Hard disk companies aksar 1 KB = 1000 bytes ginti hain, isliye 1 TB disk Windows me thoda kam dikhti hai.)

⚠️ Exam Traps:

DRAM ko refresh chahiye, SRAM ko nahi. DRAM volatile hai (non-volatile nahi).
RAM = volatile; ROM = non-volatile. Cache bhi volatile hai.
Sabse tez: Register > L1 > L2 > L3 > RAM.
CD/DVD me data magnetic charge se nahi, pits & lands (laser reflection) se.
1 KB = 1024 bytes (exam me 1000 nahi).

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. CD-ROM बाइनरी डेटा को कैसे प्रदर्शित करता है? / How does a CD-ROM represent binary data? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) Magnetic charges

(B) Pits and lands jo laser light reflect karte hain

(C) Electrical pulses

(D) Surface par ink marks

सही उत्तर: (B) Pits and lands
Laser pits aur lands se alag-alag reflect hota hai — isi se 0/1 padha jata hai.

Q2. DRAM के बारे में कौन-सा कथन सही है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) Data rakhne ke liye refreshing nahi chahiye

(B) Refresh circuit se data ko lagatar padh kar dobara likhta hai

(C) Non-volatile hai, bina power data rakhta hai

(D) ROM se dheema hai

सही उत्तर: (B)
DRAM capacitors me charge rakhta hai jo leak hota hai, isliye refresh zaroori.

Q3. सबसे अधिक उपयोग किया जाने वाला द्वितीयक भंडारण (secondary storage) माध्यम कौन-सा है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) Semiconductor chip

(B) Magnetic disk

(C) Optical fiber

(D) Cache memory

सही उत्तर: (B) Magnetic disk
Hard disk (magnetic disk) paramparik roop se sabse common secondary storage. Cache primary side ki memory hai; optical fiber cable hai.

Q4. कौन-सा कैश स्तर CPU कोर के सबसे निकट और सबसे तेज़ होता है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) L1 Cache

(B) L2 Cache

(C) L3 Cache

(D) Virtual Cache

सही उत्तर: (A) L1 Cache

Q5. कंप्यूटर सिस्टम में द्वितीयक भंडारण का उपयोग क्यों किया जाता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Processing speed badhane ke liye

(B) Primary storage ki seemit capacity aur volatility ki poorti ke liye

(C) Processing ke dauran instructions execute karne ke liye

(D) Data ko binary codes me badalne ke liye

सही उत्तर: (B)

Q6. एक हार्ड डिस्क प्रति सेक्टर कितने बाइट्स संग्रहीत करती है? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) 256 bytes

(B) 512 bytes

(C) 1024 bytes

(D) 2048 bytes

सही उत्तर: (B) 512 bytes
Standard/paramparik sector size 512 bytes (naye Advanced Format disks 4096 bytes — par options me wo nahi).

Q7. CD-ROM की तुलना में DVD-ROM के बारे में कौन-सा कथन सही है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) DVD-ROM magnetic storage use karta hai

(B) DVD-ROM ek optical storage device hai jo digital video ya computer data store karta hai

(C) DVD-ROM video data store nahi kar sakta

(D) DVD-ROM physical size me CD-ROM se chhota hai

सही उत्तर: (B)
DVD bhi optical hai, size CD jaisa (12 cm), capacity zyada.

✍️ Practice MCQs (self-made — PYQ nahi)

P1. 1 Nibble kitne bits ka hota hai? Practice MCQ

(A) 2

(B) 4

(C) 8

(D) 16

उत्तर: (B) 4

P2. Kaunsi ROM ko ultraviolet (UV) light se mitaya ja sakta hai? Practice MCQ

(A) PROM

(B) EPROM

(C) EEPROM

(D) Mask ROM

उत्तर: (B) EPROM (EEPROM electrically erase hoti hai)

P3. Bijli jaane par kis memory ka data mit jaata hai? Practice MCQ

(A) ROM

(B) Hard disk

(C) RAM

(D) Pen drive

उत्तर: (C) RAM (volatile)

📌 5. इनपुट / आउटपुट डिवाइस (Input / Output Devices) (6 min read)

5.1 Input devices (computer ko data dene wale)

Device	Khaas baat
Keyboard	QWERTY layout (C. L. Sholes); function keys F1–F12; toggle keys: Caps Lock, Num Lock, Scroll Lock
Mouse	Pointing device (Douglas Engelbart); left/right click, scroll wheel; optical/laser. Gaming mouse = programmable buttons + high-precision laser/optical sensor
Trackball, Touchpad, Joystick, Light pen, Stylus	Pointing devices; joystick — games/simulators
Scanner	Kagaz ki image ko digital banata hai (flatbed, handheld)
OCR (Optical Character Recognition)	Printed/likhe text ko editable text me badalna
OMR (Optical Mark Reader)	Gole/bubble padhna — OMR answer sheet
MICR (Magnetic Ink Character Recognition)	Bank cheque ke neeche magnetic ink wale number padhna
BCR (Barcode Reader), QR scanner	Dukano me product ka barcode
Biometric	Fingerprint, iris, face (Aadhaar authentication)
Microphone, Webcam, Digitizer/Graphics tablet	Awaaz, video, drawing input

5.2 Output devices

Monitor (VDU — Visual Display Unit): CRT (purana), LCD, LED, OLED. Screen ki sabse chhoti ikai = pixel (picture element). Resolution = pixels (jaise 1920×1080).
Printer (hard copy), Plotter (bade engineering drawings/maps/CAD), Speaker, Headphone, Projector.
Soft copy = screen par; Hard copy = kagaz par (printout).
Dono (Input + Output): Touchscreen, Headset (mic+speaker), Modem.

5.3 Printers

Impact printers (kagaz par thokte hain)	Non-impact printers (bina thoke)
Dot Matrix — pins ribbon par thok kar dots banati hain; shor, carbon copy ban sakti hai; speed CPS (characters per second)	Laser — toner (powder) + drum; ek baar me poora page → isliye "Page Printer"; speed PPM (pages per minute); sabse achchi quality
Daisy Wheel — print head daisy phool jaisa pahiya; letter-quality text, graphics nahi	Inkjet — liquid ink ki boondein spray karta hai; ghar ke liye sasta; colour photos
Line printers (Drum, Chain) — ek baar me ek line; speed LPM (lines per minute); mainframe	Thermal — heat-sensitive kagaz (ATM slip, bill receipt); 3D printer — 3-D objects

Print quality = DPI (dots per inch).

⚠️ Exam Traps:

"Page printer" = Laser. "Daisy flower head" = Daisy wheel.
Cheque = MICR; exam answer sheet = OMR; printed text → editable = OCR.
Scanner = input; Plotter = output; Touchscreen = dono.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. कौन-सा प्रिंटर प्रकार पेज प्रिंटर के नाम से भी जाना जाता है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) Ink-jet printer

(B) Laser printer

(C) Dot matrix printer

(D) Daisy wheel printer

सही उत्तर: (B) Laser printer
Laser printer poore page ki image drum par banakar ek saath print karta hai.

Q2. गेमिंग माउस को अलग पहचान देने वाली विशेषता कौन-सी है? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) USB connectivity

(B) Programmable buttons and laser optics

(C) Infrared motion sensing

(D) Built-in display

सही उत्तर: (B)
USB to har mouse me hota hai; gaming mouse ki pehchaan extra programmable buttons + precise sensor.

Q3. कौन-सा प्रिंटर डेज़ी फूल के आकार वाले प्रिंट हेड का उपयोग करता है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) Dot Matrix Printer

(B) Daisy Wheel Printer

(C) Drum Printer

(D) Line Printer

सही उत्तर: (B) Daisy Wheel Printer

✍️ Practice MCQs (self-made — PYQ nahi)

P1. Bank cheque ke neeche chhape number padhne ke liye kaunsi technology use hoti hai? Practice MCQ

(A) OMR

(B) OCR

(C) MICR

(D) BCR

उत्तर: (C) MICR

P2. Inme se kaunsa impact printer hai? Practice MCQ

(A) Laser

(B) Inkjet

(C) Dot matrix

(D) Thermal

उत्तर: (C) Dot matrix

📌 6. सॉफ्टवेयर एवं प्रोग्रामिंग भाषाएँ (Software & Languages) (7 min read)

6.1 System software vs Application software

System Software	Application Software
Hardware ko chalata hai aur doosre software ke liye platform deta hai	User ke specific kaam ke liye (letter likhna, photo edit, billing)
Memory, CPU, I/O devices jaise resources ko manage aur alag-alag programs ko allocate karta hai	System software ke upar chalta hai
Examples: Operating System, device drivers, utility programs (antivirus, disk cleanup, defragmenter, file compression), language translators, firmware (BIOS)	Examples: MS Word, Excel, browser, VLC, Tally, Photoshop, games, railway reservation software

Device driver = system software jo OS ko hardware device (printer, graphics card) se baat karne deta hai. (Application software nahi!)
Firmware = hardware ke andar (ROM/flash) permanently rakha system-level software, jaise BIOS. (Application software nahi!)
Horizontal application = general-purpose, har industry ke log use karein (Word, Excel, browser). Vertical application = kisi ek industry ke liye (hospital management, bank core-banking, school ERP).
Itihaas: 1940s ke ant me application software ko users khud apne hardware aur zaroorat ke hisaab se custom likhte the — readymade software baad me aaye.
"App" shabd ko lokpriya banaya 2008 me Apple ke iOS App Store ke launch ne.

6.2 OS / System software ki visheshtayen aur kamiyan

Functions: process/processor management (scheduling), memory management, file management, device management, security, job accounting, error-detecting aids (dumps, traces, error messages, debugging), user interface.
Kamiyan (disadvantages): System Overhead — khud CPU/RAM ghar leta hai, computer dheema ho sakta hai; Limited Customizability — computing anubhav ko apne hisaab se badalna mushkil; Dependency; Cost; Upgrades ki zaroorat.

6.3 Licence ke hisaab se software

Type	Matlab	Example
Open Source	Source code sabke liye khula; badal/baant sakte hain	Linux, Android (AOSP), Firefox, LibreOffice, VLC
Proprietary / Closed	Code company ka; licence lena padta hai	Windows, MS Office, macOS
Freeware	Muft par code band	Adobe Acrobat Reader
Shareware / Trial	Kuch din muft, phir paisa	Trial versions

6.4 Programming languages aur translators

Machine language (0 aur 1) — CPU sirf yahi seedhe samajhta hai. Assembly language — mnemonics (ADD, MOV). High-level language — English jaisi (C, Java, Python).
Assembler: assembly → machine code. Compiler: poora program ek saath translate, phir errors ki list (C, C++). Interpreter: line-by-line translate aur chalana; error par wahin rukta hai (Python, BASIC).
Pehli high-level language: FORTRAN (1957, IBM — scientific). COBOL — business. C — Dennis Ritchie (1972). Java — James Gosling (Sun). Python — Guido van Rossum. HTML — web page banane ki markup language (programming language nahi).
Source code (programmer ka likha) → Object code (translate hone ke baad). Program ki galti = bug; hatana = debugging.
Algorithm = step-by-step hal; Flowchart = uska chitra — Oval (start/end), Parallelogram (input/output), Rectangle (process), Diamond (decision).

⚠️ Exam Traps:

OS, device driver, utility, firmware = system software. Word/Excel/browser = application.
System software platform deta hai; application software user ka specific kaam karta hai — ulta wala option galat.
Compiler poora ek saath; interpreter line-by-line.
Performance dheema karne wali kami = System overhead; personalise na kar paana = Limited customizability.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. सिस्टम सॉफ़्टवेयर की कौन-सी कमी कंप्यूटर के प्रदर्शन को धीमा कर सकती है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) Cost

(B) Upgrades

(C) Dependency

(D) System Overhead

सही उत्तर: (D) System Overhead
System software khud resources (CPU time, RAM) use karta hai — isse performance ghat sakti hai.

Q2. निम्नलिखित में से कौन-सा कथन सही है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) System software memory, CPU aur I/O devices jaise resources ko programs ke beech manage aur allocate karta hai

(B) OS apne file management ke through process schedule karta hai

(C) Device drivers application software ka prakar hain

(D) Firmware application software ka prakar hai

सही उत्तर: (A)
(B) galat — scheduling process management ka kaam hai; (C), (D) galat — drivers aur firmware system software hain.

Q3. कौन-सा कथन सिस्टम सॉफ़्टवेयर और एप्लिकेशन सॉफ़्टवेयर के बीच सही अंतर बताता है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) System software end-user kaam (documents) ke liye

(B) Application software doosre software ko platform deta hai

(C) System software doosre software ko platform deta hai, jabki application software users ko specific kaam karne deta hai

(D) Dono interchangeable hain

सही उत्तर: (C)

Q4. 1940 के दशक के अंत में एप्लिकेशन सॉफ़्टवेयर के बारे में कौन-सा कथन सही था? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Hardware manufacturers dete the

(B) Computer users khud specific hardware aur zaroorat ke hisaab se custom likhte the

(C) OS ke saath bundle hota tha

(D) Sirf gaming ke liye

सही उत्तर: (B)

Q5. क्षैतिज (horizontal) और ऊर्ध्वाधर (vertical) एप्लिकेशन सॉफ़्टवेयर के बीच मुख्य अंतर क्या है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Horizontal niche, vertical general-purpose

(B) Horizontal general-purpose; vertical industry-specific

(C) Dono industry-specific

(D) Dono general-purpose

सही उत्तर: (B)

Q6. सिस्टम सॉफ़्टवेयर की कौन-सी विशेषता डंप्स, ट्रेसेस, एरर मैसेज और डिबगिंग के उत्पादन से संबंधित है? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) Scheduling

(B) Memory Management

(C) Error-detecting Aids

(D) Processor Management

सही उत्तर: (C) Error-detecting Aids

Q7. कौन-सी घटना ने "ऐप" (app) संक्षिप्त रूप को लोकप्रिय बनाया? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) 2011 me Windows Store

(B) 2008 me iOS App Store ki shuruaat

(C) 2007 me Android OS

(D) 2010 me Mac App Store

सही उत्तर: (B) 2008 — iOS App Store
Apple App Store July 2008 me aaya; iske baad "app" shabd aam bol-chaal me aa gaya.

Q8. सिस्टम सॉफ़्टवेयर की कौन-सी कमी कंप्यूटिंग अनुभव को व्यक्तिगत (personalize) बनाने में कठिनाई को दर्शाती है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) Limited Customizability

(B) Upgrades

(C) Dependency

(D) Cost

सही उत्तर: (A) Limited Customizability

✍️ Practice MCQs (self-made — PYQ nahi)

P1. High-level program ko line-by-line translate karke chalane wala translator? Practice MCQ

(A) Compiler

(B) Assembler

(C) Interpreter

(D) Loader

उत्तर: (C) Interpreter

P2. Inme se kaunsa open-source software hai? Practice MCQ

(A) MS Windows

(B) Linux

(C) MS Office

(D) macOS

उत्तर: (B) Linux

📌 7. ऑपरेटिंग सिस्टम एवं Windows (Operating System & Windows) (10 min read)

7.1 Operating System (OS) kya hai?

OS = user aur hardware ke beech ka interface + resource manager. Computer on hote hi sabse pehle load hone wala main software.
Booting = OS ko RAM me load karna. BIOS/UEFI → POST (Power-On Self-Test) → bootloader → OS. Cold boot = band se chalu; Warm boot = restart.
Interface: CLI (Command Line — MS-DOS, Linux terminal; commands type karte hain) vs GUI (Graphical — icons, windows, mouse: Windows, macOS).
Types: Batch, Multiprogramming, Multitasking/Time-sharing, Multiprocessing, Real-Time OS (turant response — missile, ABS brake, medical), Distributed, Network OS, Mobile OS, Embedded.

OS	Company / Kisne	Type
Windows	Microsoft (Bill Gates & Paul Allen ki company); Windows 1.0 — 1985; Windows 11 — 2021	Proprietary graphical OS
MS-DOS	Microsoft	CLI, single-user
macOS / iOS	Apple	Proprietary
Linux	Linus Torvalds (kernel, 1991)	Open source; distros — Ubuntu, Fedora, Debian; BOSS Linux (India, C-DAC)
UNIX	Ken Thompson & Dennis Ritchie, Bell Labs (1969)	Multi-user
Android	Google (Linux kernel par aadharit)	Open-source mobile OS

Linux kyun bana? Richard Stallman ke GNU project (free OS) ke paas kaam karne wala kernel nahi tha; Linus Torvalds ka Linux kernel + GNU tools = poora free OS (GNU/Linux).
Linux desktop environments: GNOME, KDE Plasma, Xfce. (X11 aur Wayland = display server/protocol; LAMP = Linux-Apache-MySQL-PHP web stack — ye desktop environment nahi.)

7.2 Windows ke hisse (Desktop & Taskbar)

Desktop — pehli screen; icons (This PC, Recycle Bin). Wallpaper = background image.
Taskbar (neeche ki patti): Start button, search, Task View, pinned/open apps, aur daayen kone me Notification Area (System Tray) — ghadi (clock), date, volume, network, battery, notifications.
Taskbar ke khaali hisse par right-click → Taskbar context menu (Task Manager, Taskbar settings).
Task View (Win + Tab) — saari khuli windows aur virtual desktops ek saath.
Recycle Bin — Delete ki gayi files yahan jaati hain (Restore kar sakte hain). Shift + Delete = seedha permanent delete (Recycle Bin me nahi). Pen drive se delete ki files aam taur par Recycle Bin me nahi jaati.

7.3 Control Panel

Option	Kaam
Programs and Features	Software uninstall / change karna
Ease of Access	Divyang users ke liye accessibility — Narrator, Magnifier, On-Screen Keyboard, high contrast
Device Manager	Hardware aur drivers dekhna/update karna
Network and Sharing Center	Network settings

Control Panel kholne ke tareeke: Start menu/search se; Run dialog (Win + R) me "control" likh kar; Command Prompt me "control" likh kar. BIOS settings se Control Panel nahi khulta (BIOS to OS load hone se pehle ka firmware setup hai).

7.4 Files aur Folders

File = naam wala data ka sangrah (document, photo). Folder (Directory) = files rakhne ka container; folder ke andar subfolder/subdirectory bana kar behtar prabandhan kar sakte hain. Files ko baad me rename bhi kar sakte hain (F2).
Root directory = drive ka sabse upar ka folder, jaise C:\. Path = C:\Users\Anjali\Documents\notes.docx.
Windows me default maximum path length = 260 characters (MAX_PATH); ek file/folder naam max 255 characters.
File naam me ye characters nahi aa sakte: \ / : * ? " < > |
File extension (naam ke baad ka hissa, jaise .docx) batata hai file kis type ki hai aur kaunsa default program use kholega. Windows me extension case-sensitive nahi (.PDF = .pdf).
Command Prompt (cmd) commands: dir (files list), dir /a (hidden samet saari files), cd (folder badlo), md/mkdir (folder banao), rd (folder hatao), copy, del, cls (screen saaf), ipconfig (IP dekhna), ping (connection check). (ls -a Linux ka command hai.)
Silent Installation = software ko bina user interaction/prompts ke install karna (IT departments me). .msi package ke liye: msiexec /quiet /i filename.msi (ya msiexec /i filename.msi /quiet).

7.5 Windows keyboard shortcuts (bahut zaroori)

Shortcut	Kaam	Shortcut	Kaam
Ctrl + C / X / V	Copy / Cut / Paste	Ctrl + Z / Y	Undo / Redo
Ctrl + A	Sab select	F2	Rename
Ctrl + Shift + N	New folder (File Explorer)	Shift + Delete	Permanent delete
Win + D	Desktop dikhana	Win + E	File Explorer
Win + L	Computer lock	Win + Tab	Task View
Alt + Tab	Khuli windows ke beech switch	Alt + F4	Window/program band
Ctrl + Shift + Esc	Task Manager seedha	Ctrl + Alt + Del	Security screen (Lock, Task Manager)
Win + R	Run dialog	Win + I	Settings
Win + Shift + S	Screenshot (Snipping)	Alt + Enter	Properties

⚠️ Exam Traps:

Windows = proprietary graphical OS (open-source nahi). Linux = open source.
Ghadi/notifications = Notification Area (System Tray), Start menu nahi.
Uninstall = Programs and Features; accessibility = Ease of Access.
Hidden files dikhane ke liye Windows cmd me dir /a (dir /h koi standard option nahi; ls -a Linux ka).
Win + Tab = Task View; Alt + Tab = switch windows.
Path limit 260 (256 nahi).

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. फ़ाइल एक्सटेंशन के बारे में कौन-सा कथन सही है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) Windows me extensions case-sensitive hote hain

(B) Extensions me spaces ho sakte hain

(C) Extension tay karta hai ki file kholne ke liye default program kaunsa hoga

(D) Windows me extensions vaikalpik hain

सही उत्तर: (C)
.docx → Word, .xlsx → Excel, .pdf → PDF reader. Windows me extensions case-sensitive nahi.

Q2. कंट्रोल पैनल में "Ease of Access" का कार्य क्या है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) Divyang users ke liye accessibility suvidhaon ka prabandhan

(B) Network settings configure karna

(C) Programs uninstall karna

(D) Storage devices manage karna

सही उत्तर: (A)

Q3. टास्कबार का कौन-सा भाग सामान्यतः सिस्टम नोटिफ़िकेशन और घड़ी प्रदर्शित करता है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) Start Menu

(B) Quick Launch

(C) Notification Area (System Tray)

(D) Task View

सही उत्तर: (C) Notification Area (System Tray)

Q4. जब आप टास्कबार के खाली क्षेत्र पर राइट-क्लिक करते हैं तो क्या होता है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) File Explorer khulta hai

(B) Desktop icons dikhte hain

(C) Task Manager jaise options ke saath Taskbar context menu

(D) Start Menu khulta hai

सही उत्तर: (C)

Q5. माइक्रोसॉफ़्ट विंडोज़ किस प्रकार का ऑपरेटिंग सिस्टम है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) Open-source graphical OS

(B) Command-line based OS

(C) Proprietary graphical operating system

(D) Sirf real-time embedded OS

सही उत्तर: (C) Proprietary graphical OS

Q6. निम्नलिखित में से कौन-सा एक सामान्य लिनक्स डेस्कटॉप वातावरण है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) GNOME

(B) X11

(C) Wayland

(D) LAMP

सही उत्तर: (A) GNOME
X11/Wayland display protocols hain, LAMP web server stack.

Q7. प्रोग्राम्स को अनइंस्टॉल करने के लिए कंट्रोल पैनल ऑप्शन को ____ कहा जाता है। MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) Programs and Features

(B) Network and Sharing Center

(C) Device Manager

(D) Ease of Access

सही उत्तर: (A) Programs and Features

Q8. लिनक्स कर्नेल किसने डिज़ाइन किया और क्यों? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) Richard Stallman, Windows ko replace karne

(B) Linus Torvalds, GNU ke liye kaaryasheel kernel ki kami ke kaaran

(C) Dennis Ritchie, Unix performance sudharne

(D) Ken Thompson, embedded systems ke liye

सही उत्तर: (B) Linus Torvalds

Q9. विंडोज में डिफ़ॉल्ट रूप से अधिकतम पाथ लंबाई कितनी समर्थित होती है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) 128 characters

(B) 256 characters

(C) 260 characters

(D) Unlimited

सही उत्तर: (C) 260 characters
Microsoft documentation: MAX_PATH = 260.

Q10. विंडोज़ में फ़ाइल बनाने और व्यवस्थित करने के बारे में कौन-सा कथन सही है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) Files sirf Command Prompt se banti hain

(B) Files ko behtar prabandhan ke liye folders aur subdirectories me vyavasthit kar sakte hain

(C) Banane ke baad naam nahi badal sakte

(D) Files hamesha root directory me hi rakhni hoti hain

सही उत्तर: (B)

Q11. विंडोज़ में साइलेंट इंस्टॉलेशन का क्या कार्य होता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Bina user interaction ya prompts ke software install karta hai

(B) Vistrit logs aur prompts ke saath install

(C) Sirf Safe Mode me install

(D) Bina shortcuts banaye install

सही उत्तर: (A)

Q12. .msi पैकेज को साइलेंटली इंस्टॉल करने के लिए इस्तेमाल की जाने वाली कमांड ____ है। MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) msiexec /quiet /i filename.msi

(B) install filename.msi

(C) setup filename.msi

(D) wmic install filename.msi

सही उत्तर: (A)
msiexec Windows Installer ka tool hai; /i = install, /quiet = bina prompts.

Q13. विंडोज कमांड प्रॉम्प्ट में कौन-सा कमांड सभी फाइलों को (छिपी हुई फाइलों सहित) प्रदर्शित करता है? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) show hidden

(B) ls -a

(C) dir /a

(D) dir /h

सही उत्तर: (C) dir /a
/a = all attributes (hidden, system samet). ls -a Linux ka command hai.

Q14. विंडोज 10/11 में टास्क व्यू खोलने के लिए कौन-सा शॉर्टकट उपयोग किया जाता है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Ctrl + Tab

(B) Windows + Tab

(C) Shift + Tab

(D) Alt + Tab

सही उत्तर: (B) Windows + Tab

Q15. विंडोज़ में कंट्रोल पैनल खोलने का कौन-सा तरीका मान्य नहीं है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Start Menu

(B) Run dialog (control)

(C) Command Prompt (control)

(D) BIOS settings

सही उत्तर: (D) BIOS settings

Q16. विंडोज़ एक्सप्लोरर में नया फ़ोल्डर बनाने के लिए कौन-सी शॉर्टकट की प्रयुक्त होती है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) Alt + N

(B) Shift + F10

(C) Ctrl + Shift + N

(D) Ctrl + N

सही उत्तर: (C) Ctrl + Shift + N
Ctrl + N File Explorer me nayi window kholta hai; Shift + F10 = right-click menu.

✍️ Practice MCQs (self-made — PYQ nahi)

P1. File ko Recycle Bin me bheje bina permanently delete karne ki shortcut? Practice MCQ

(A) Ctrl + Delete

(B) Alt + Delete

(C) Shift + Delete

(D) Win + Delete

उत्तर: (C) Shift + Delete

P2. Computer chalu hone par hardware jaanch (self-test) ko kya kehte hain? Practice MCQ

(A) BOOT

(B) POST

(C) BIOS

(D) CMOS

उत्तर: (B) POST — Power-On Self-Test (BIOS ise chalata hai).

P3. Missile guidance ya ABS brakes me kis prakar ka OS use hota hai? Practice MCQ

(A) Batch OS

(B) Real-Time OS

(C) Time-sharing OS

(D) Network OS

उत्तर: (B) Real-Time OS

📌 8. MS Word (वर्ड प्रोसेसर) (8 min read)

8.1 Basics

MS Word = word processor — letter, report, application type karna aur format karna. Microsoft Office ka hissa. (Free vikalp: LibreOffice Writer, Google Docs.)
File extension: .docx (Word 2007 se), purana .doc; template .dotx; macro wali .docm.
Default font: Word 2007 se Calibri, 11 pt; naye Microsoft 365 versions me Microsoft ne default Aptos kar diya hai.
Orientation: Portrait (khada page) / Landscape (leta page). Zoom range 10%–500%.

8.2 Ribbon tabs — kaunsa feature kahan

Tab	Features
Home	Font, bold/italic, alignment, bullets, Styles, Find/Replace, Format Painter (formatting copy karna)
Insert	Table, Picture, Shapes, SmartArt, Chart, Hyperlink, Header/Footer, Page Number, Text Box, WordArt, Symbol, Equation, Object → Text from File
Design	Themes, Watermark, Page Color, Page Borders
Layout	Margins, Orientation, Size, Columns, Breaks (Page/Section)
References	Table of Contents, Footnote (page ke neeche), Endnote (document ke ant me), Citations
Mailings	Mail Merge, Envelopes, Labels
Review	Spelling & Grammar, Thesaurus, Word Count, Comments, Track Changes, Restrict Editing
View	Read Mode, Print Layout, Web Layout, Outline, Draft; Ruler, Zoom, Macros

8.3 Zaroori features samjhein

Mail Merge — ek hi letter/invitation ko bahut logon ko unke naam-pate ke saath banana. Do cheezein: Main document + Data source (Excel/list).
Kai documents ko ek me jodna — Insert → Object → Text from File. (Mail merge ye kaam nahi karta.)
Track Changes — kisne kya badla uska record (editing/review).
Section Break — document ko sections me baantta hai jinki formatting alag ho sakti hai (alag orientation, header, page numbering). Page Break (Ctrl + Enter) — bas content ko agle page par bhej deta hai.
Restrict Editing (Review tab) — document par formatting aur editing permissions seemit karna (jaise sirf comments ki anumati).
Styles = text ke liye readymade formatting (Heading 1, Heading 2) — inhi se Table of Contents banti hai. Themes = poore document ke liye colours + fonts + effects ka set. Templates = readymade document design file (.dotx) jaise resume, letter.
Drop Cap = paragraph ka pehla bada akshar. Watermark = page ke peechhe halka text/logo ("CONFIDENTIAL").

8.4 Word shortcuts

Shortcut	Kaam	Shortcut	Kaam
Ctrl + N / O / S	New / Open / Save	F12	Save As
Ctrl + P	Print	Ctrl + W	Document band
Ctrl + B / I / U	Bold / Italic / Underline	Ctrl + E / L / R / J	Center / Left / Right / Justify
Ctrl + K	Hyperlink	Ctrl + F	Find (Navigation pane)
Ctrl + H	Find and Replace	Ctrl + G (ya F5)	Go To
Ctrl + Enter	Page break	F7	Spelling & Grammar
Shift + F7	Thesaurus (samanarthi)	Shift + F3	Change case (UPPER/lower)
Ctrl + Shift + > / <	Font size badhana / ghatana	Ctrl + D	Font dialog
Ctrl + 1 / 2 / 5	Line spacing 1 / 2 / 1.5	Ctrl + = / Ctrl + Shift + =	Subscript / Superscript
Ctrl + Home / End	Document ki shuruaat / ant	Ctrl + Shift + C / V	Format copy / paste

⚠️ Exam Traps:

Ctrl + H = Replace (Word me); Ctrl + K = Hyperlink; Ctrl + R = right align (Redo nahi — Redo Ctrl + Y).
Word me F5 = Go To, PowerPoint me F5 = Slide show.
Docs jodna = Insert → Object → Text from File; Mail Merge = ek letter kai logon ko.
Spelling check = F7; Thesaurus = Shift + F7.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. कौन-सी एमएस वर्ड सुविधा कई दस्तावेज़ों को एक में संयोजित करने के लिए उपयोग की जाती है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) Merge Tool

(B) Insert → Object → Text from File

(C) Track Changes

(D) Mail Merge

सही उत्तर: (B) Insert → Object → Text from File
Isse doosri Word file ka poora text current document me aa jaata hai. Mail Merge ek letter ko kai recipients ke liye banata hai.

Q2. एमएस वर्ड में "Restrict Editing" फीचर का क्या कार्य होता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Text ko chhipana

(B) Document ke liye formatting aur editing permissions seemit karna

(C) Document ko poori tarah lock karna

(D) Document ko PDF me badalna

सही उत्तर: (B)
(Note: English prashn me typing error se "C feature" chhapa tha; Hindi me "Restrict Editing" spasht tha.)

Q3. एमएस वर्ड में "सेक्शन ब्रेक" और "पेज ब्रेक" में क्या अंतर है? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) Section Break content ko swatantra formatting wale sections me baantta hai; Page Break sirf content ko agle page par le jaata hai

(B) Dono ek hi kaam karte hain

(C) Page Break orientation badalta hai, Section Break nahi

(D) Section Break headers delete karta hai

सही उत्तर: (A)

Q4. एमएस वर्ड में "Find and Replace" डायलॉग बॉक्स खोलने के लिए शॉर्टकट की कुंजी है: MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) Ctrl + H

(B) Ctrl + F

(C) Ctrl + G

(D) Ctrl + R

सही उत्तर: (A) Ctrl + H
Naye Word me Ctrl + F Navigation pane (search) kholta hai; Find and Replace dialog Ctrl + H se.

Q5. एमएस वर्ड में हाइपरलिंक डालने के लिए शॉर्टकट की कुंजी ____ है। MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Ctrl + K

(B) Ctrl + H

(C) Ctrl + L

(D) Ctrl + U

सही उत्तर: (A) Ctrl + K

✍️ Practice MCQs (self-made — PYQ nahi)

P1. MS Word me Mail Merge kis tab me milta hai? Practice MCQ

(A) Insert

(B) Review

(C) Mailings

(D) References

उत्तर: (C) Mailings

P2. MS Word me spelling aur grammar check ki shortcut key? Practice MCQ

(A) F5

(B) F7

(C) F12

(D) F1

उत्तर: (B) F7

P3. Word me text ko dono margins ke barabar (Justify) karne ki shortcut? Practice MCQ

(A) Ctrl + E

(B) Ctrl + J

(C) Ctrl + L

(D) Ctrl + R

उत्तर: (B) Ctrl + J

📌 9. MS Excel (स्प्रेडशीट) (10 min read)

9.1 Basics

Excel = spreadsheet program — tables, ganana, charts. File = Workbook (.xlsx; purana .xls; macro .xlsm; template .xltx); workbook ke andar Worksheets (sheets).
Row = number (1, 2, 3…), Column = letter (A, B, C…). Cell = row-column ka milan; address jaise C5. Range = A1:A10. Chuna hua cell = Active cell.
Ek sheet me 1,048,576 rows × 16,384 columns (aakhri column XFD) — Excel 2007 se.
Name Box (active cell ka address) aur Formula Bar (cell ka formula/content).
Itihaas: pehla spreadsheet VisiCalc (1979); 1980s me dominant tha Lotus 1-2-3 — Excel (1985) ne shuru me Lotus 1-2-3 se muqabla kiya. Vikalp: Google Sheets, LibreOffice Calc.

9.2 Formula aur cell references

Har formula = (barabar) se shuru. Operators ka kram: ^ (power) → * / → + −; & = text jodna. Udaharan: =2+3*4 = 14; =(2+3)*4 = 20.
Relative reference (A1) — copy karne par badal jaata hai. Absolute ($A$1) — copy karne par fixed rehta hai. Mixed ($A1 ya A$1). F4 dabane se ye badalte hain.

9.3 Zaroori functions

Function	Kaam / Udaharan
SUM, AVERAGE, MAX, MIN	`=SUM(A1:A5)` jod; AVERAGE = ausat
COUNT / COUNTA / COUNTBLANK	COUNT = sirf numbers wale cells; COUNTA = saare non-empty; COUNTBLANK = khaali
COUNTIF, SUMIF	Shart (condition) ke saath ginna/jodna — `=COUNTIF(B2:B50,">=33")`
IF	`=IF(B2>=33,"Pass","Fail")`
VLOOKUP	Table ke pehle column me vertically value khoj kar usi row ka doosre column ka maan lautaana — `=VLOOKUP(101,A2:D50,3,FALSE)`
HLOOKUP / XLOOKUP	HLOOKUP = horizontally (pehli row me); XLOOKUP = naya, dono disha me
CONCATENATE / CONCAT / TEXTJOIN	Kai cells ka text ek cell me jodna (ya `=A1&" "&B1`)
TODAY(), NOW()	Aaj ki date; date + time
ROUND, INT, MOD, ABS, SQRT, POWER	`=ROUND(3.456,2)`=3.46; `=MOD(10,3)`=1; `=SQRT(16)`=4; `=POWER(2,3)`=8
LEN, UPPER, LOWER, PROPER, TRIM	`=LEN("MP Police")`=9 (space bhi ginta hai)

9.4 Features

Conditional Formatting — cell ki value ke aadhar par formatting (jaise 33 se kam marks laal).
Data Validation — cell me kya daal sakte hain uski seema (jaise sirf 1–100, dropdown list).
Sort, Filter (Ctrl + Shift + L), Pivot Table (bade data ka saaransh), Freeze Panes (heading row rok kar rakhna), Goal Seek / What-If Analysis, Flash Fill, Macros.
Charts: Column, Bar, Line (trend), Pie (ek series ke hisse — pura = 100%), Scatter.
Error values: #DIV/0! (0 se bhag), #N/A (value nahi mili — lookup), #NAME? (function naam galat), #REF! (cell reference mita), #VALUE! (galat type ka data), #NUM!, #NULL!, ##### (column chhota hai).

9.5 Excel shortcuts

Shortcut	Kaam	Shortcut	Kaam
Ctrl + 1	Format Cells dialog	Alt + F1	Chart insert (usi sheet par embedded)
F11	Chart alag chart sheet par	Shift + F11	Nayi worksheet
F2	Cell edit	F4	Reference $ toggle / last action repeat
Alt + =	AutoSum	Ctrl + ; / Ctrl + Shift + ;	Aaj ki date / time
Alt + Enter	Cell ke andar nayi line	Ctrl + Page Up/Down	Sheets ke beech
Ctrl + Space / Shift + Space	Poora column / row select	Ctrl + D / Ctrl + R	Fill down / Fill right
Ctrl + T	Table banana	Ctrl + Home	Cell A1 par

⚠️ Exam Traps:

Relative badalta hai, Absolute ($) fixed — ulta wala option galat.
VLOOKUP = vertical lookup (validation/sum/chart nahi).
Chart = Alt + F1 (ya F11); Shift + F11 = nayi sheet. Format Cells = Ctrl + 1.
Value ke aadhar par rang = Conditional Formatting; entry par rok = Data Validation.
Text jodne ka function = CONCATENATE/CONCAT (MERGE() ya COMBINE() koi function nahi).

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. माइक्रोसॉफ़्ट एक्सेल ने मूल रूप से किस प्रमुख स्प्रेडशीट सॉफ़्टवेयर से प्रतिस्पर्धा की थी? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) VisiCalc

(B) Lotus 1-2-3

(C) Quattro Pro

(D) Google Sheets

सही उत्तर: (B) Lotus 1-2-3
1980s me Lotus 1-2-3 ka market par dabdaba tha; Excel (1985) usi ko takkar dene aaya.

Q2. एक्सेल में VLOOKUP का क्या कार्य है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) Cell me data validate karna

(B) Table me vertically value khojna aur sambandhit value lautaana

(C) Vertical sums ki ganana

(D) Chart banana

सही उत्तर: (B)

Q3. एक्सेल में चार्ट इंसर्ट करने के लिए शॉर्टकट की कुंजी ____ है। MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) Alt + F1

(B) Ctrl + F1

(C) Shift + F11

(D) Ctrl + Alt

सही उत्तर: (A) Alt + F1
Alt + F1 selected data ka chart usi sheet par banata hai (F11 alag chart sheet par). Shift + F11 nayi worksheet dalta hai; Ctrl + F1 ribbon chhota-bada karta hai.

Q4. एक्सेल में "Format Cells" डायलॉग बॉक्स खोलने के लिए शॉर्टकट की कुंजी ____ है। MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) Ctrl + 1

(B) Ctrl + F

(C) Ctrl + Shift + F

(D) Alt + F1

सही उत्तर: (A) Ctrl + 1

Q5. कई सेल्स के टेक्स्ट को एक सेल में मिलाने के लिए इस्तेमाल किया जाने वाला फ़ंक्शन ____ है। MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) CONCATENATE or CONCAT/TEXTJOIN

(B) MERGE()

(C) COMBINE()

(D) SumUp()

सही उत्तर: (A)

Q6. एक्सेल में "Relative" और "Absolute" सेल रेफरेंस में क्या अंतर है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Absolute reference formula me use nahi hote

(B) Copy karne par relative badal jaate hain; absolute fixed rehte hain

(C) Dono ek jaise

(D) Relative fixed, absolute badalte hain

सही उत्तर: (B)

Q7. सेल वैल्यू के आधार पर फ़ॉर्मेटिंग लागू करने वाले एक्सेल फ़ीचर को ____ कहा जाता है। MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Data Validation

(B) Conditional Formatting

(C) AutoFormat

(D) Pivot Formatting

सही उत्तर: (B) Conditional Formatting

✍️ Practice MCQs (self-made — PYQ nahi)

P1. Excel me =2^3*2 ka result kya hoga? Practice MCQ

(A) 12

(B) 16

(C) 64

(D) 10

उत्तर: (B) 16 — pehle 2^3 = 8, phir 8×2 = 16.

P2. Kisi number ko 0 se bhag dene par Excel kaunsa error dikhata hai? Practice MCQ

(A) #N/A

(B) #REF!

(C) #DIV/0!

(D) #NAME?

उत्तर: (C) #DIV/0!

P3. Excel me absolute cell reference kaunsa hai? Practice MCQ

(A) A1

(B) $A1

(C) A$1

(D) $A$1

उत्तर: (D) $A$1 ((B), (C) mixed hain)

📌 10. MS PowerPoint एवं File Extensions (6 min read)

10.1 PowerPoint basics

PowerPoint = presentation software; har page = slide. File: .pptx (purana .ppt); .ppsx = seedha slide show me khulti hai; template .potx.
Slide Master — ek jagah badlav karo, saari slides par design lag jaaye. Layouts — title slide, title & content aadi.
Transition = ek slide se doosri slide par jaane ka effect. Animation = slide ke andar kisi object (text/picture) par effect.
Animation Pane — saari animations ki list, kram aur timing. Animation Painter — ek object ki animation ko jaldi se doosre objects par copy karna (Format Painter jaisa). Motion Path — object ko custom raaste par chalana.
Group (Ctrl + G) — kai objects ko ek object me jodna; Ungroup = Ctrl + Shift + G. (Align = objects ko line me lagana.)
Views: Normal, Outline View, Slide Sorter (saari slides chhote roop me — kram badalna), Notes Page, Reading View, Slide Show; presenter ke liye Presenter View. Speaker notes aur Handouts print kar sakte hain.

10.2 PowerPoint shortcuts

Shortcut	Kaam	Shortcut	Kaam
F5	Slide show shuru se	Shift + F5	Slide show current slide se
Ctrl + M	Nayi slide	Ctrl + D	Duplicate
Esc	Slide show band	B / W	Show ke dauran kaali / safed screen
Ctrl + G	Group	N ya → / P ya ←	Agli / pichhli slide

10.3 Important file extensions

Extension	File type	Extension	File type
.docx / .doc	Word document	.txt	Plain text (Notepad)
.xlsx / .xls / .csv	Excel / comma-separated data	.pdf	Portable Document Format (Adobe)
.pptx / .ppt / .ppsx	PowerPoint / show	.accdb / .mdb	MS Access database
.jpg/.jpeg, .png, .gif, .bmp, .tiff, .svg	Images (GIF me animation)	.mp3, .wav, .aac	Audio
.mp4, .avi, .mkv, .mov	Video	.exe, .msi	Windows program / installer
.zip, .rar, .7z	Compressed	.html / .htm	Web page
.apk	Android app	.iso	Disc image
.bat	Batch file (commands)	.dll, .sys	Windows system library/files

MS Office ke anya apps: Access (database), Outlook (email/calendar), OneNote (notes), Publisher (brochures). Google ke vikalp: Docs, Sheets, Slides.

⚠️ Exam Traps:

F5 = shuru se; Shift + F5 = current slide se.
Transition = slide-to-slide; Animation = object par.
Objects jodna = Group (Merge/Combine nahi). Animation copy = Animation Painter.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. पावरपॉइंट का कौन-सा फ़ीचर आपको कई ऑब्जेक्ट्स को एक साथ जोड़ने की सुविधा देता है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) Group

(B) Merge

(C) Combine

(D) Align

सही उत्तर: (A) Group

Q2. पावरपॉइंट का कौन-सा फ़ीचर कई ऑब्जेक्ट पर एक ही एनिमेशन इफ़ेक्ट जल्दी से लगाने की सुविधा देता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) Animation Painter

(B) Animation Pane

(C) Slide Master

(D) Motion Path

सही उत्तर: (A) Animation Painter

Q3. पावरपॉइंट में शुरुआत से स्लाइड शो शुरू करने के लिए शॉर्टकट की कुंजी ____ है। MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) F5

(B) Shift + F5

(C) Ctrl + F5

(D) Alt + F5

सही उत्तर: (A) F5

✍️ Practice MCQs (self-made — PYQ nahi)

P1. PowerPoint me nayi slide jodne ki shortcut? Practice MCQ

(A) Ctrl + N

(B) Ctrl + M

(C) Ctrl + S

(D) Ctrl + D

उत्तर: (B) Ctrl + M (Ctrl + N = nayi presentation)

P2. Saari slides ko chhote thumbnails me dekh kar unka kram badalne ke liye kaunsa view? Practice MCQ

(A) Notes Page

(B) Reading View

(C) Slide Sorter

(D) Outline

उत्तर: (C) Slide Sorter

📌 11. इंटरनेट, WWW, ब्राउज़र, URL, IP एवं DNS (12 min read — sabse zyada PYQ)

11.1 Internet aur WWW

Internet = duniya bhar ke computer networks ka network ("network of networks"). Shuruaat ARPANET (1969, USA) se. TCP/IP protocol par chalta hai (Vint Cerf & Bob Kahn). Duniya ka sabse bada WAN.
India me aam janta ke liye internet: 15 August 1995, VSNL ne shuru kiya. Internet dene wali company = ISP (Internet Service Provider) — Jio, Airtel, BSNL.
Intranet = sanstha ke andar ka private network; Extranet = intranet ka hissa jo partners/vendors ko diya jaaye.
WWW (World Wide Web) = internet par chalne wali ek service — hyperlinks se jude web pages ka sangrah. Tim Berners-Lee, 1989, CERN. Web pages HTML me bante hain aur HTTP/HTTPS se aate hain.
Website = web pages ka samooh; pehla page = Home page; websites web server par rakhi jaati hain. Hyperlink = click karke doosre page par jaana.
Web 1.0 = sirf padhna (static); Web 2.0 = interactive/social (users content banate hain); Web 3.0 = semantic/decentralised web.

11.2 Web Browser

Browser	Company / Saal
WorldWideWeb (baad me Nexus)	Tim Berners-Lee, 1990 — pehla browser
Mosaic	NCSA (Marc Andreessen), 1993 — pehla lokpriya graphical browser, isne internet ko aam logon me lokpriya banaya
Netscape Navigator	1994
Internet Explorer → Edge	Microsoft (IE 1995; Edge 2015)
Firefox	Mozilla (open source), 2004
Safari	Apple, 2003
Chrome	Google, 2008

Browser features: tabs, bookmarks, history, cache, cookies, extensions, Incognito/Private mode (history/cookies session ke baad save nahi hote — par ISP/website se chhupta nahi).
Sandboxing — har web page/tab ko alag "dabbe" me chalana taaki malicious code poore browser/computer ko prabhavit na kare. Chrome aur Firefox dono me; saath me HTTPS enforcement (HTTPS-only mode).
PWA (Progressive Web App) — website ko app ki tarah chalana/install karna, bina native app install kiye.
Chrome aur Firefox dono tez page loading ke liye HTTP/2 aur HTTP/3 support karte hain (HTTP/3 = QUIC protocol par).

11.3 Search Engine

Google — 1998, Larry Page & Sergey Brin; ranking ke liye PageRank algorithm (Larry Page ke naam par); quick jawab ke liye "Featured Snippets" Google ne shuru kiye.
Bing — Microsoft (2009). Yahoo, DuckDuckGo (privacy — tracking nahi), Baidu (China), Yandex (Russia).
Search engine web crawler/spider se pages padhta hai, index banata hai, phir rank karta hai. SEO = Search Engine Optimization.

11.4 URL (Uniform Resource Locator) — web address

https://www.mppolice.gov.in:443/recruitment/notice.html?id=5#top

Hissa	Udaharan	Matlab
Scheme / Protocol	https	Kaunsa protocol use hoga (URL ka protocol batane wala hissa)
Subdomain	www	—
Domain name / Host	mppolice.gov.in	Website ka naam; TLD = .in
Port number	:443	Optional (vaikalpik) — na likhen to default (HTTP 80, HTTPS 443)
Path	/recruitment/notice.html	Server par file ka raasta
Query string / Fragment	?id=5 / #top	Extra parameters / page ka hissa

Domain types: generic TLD — .com (commercial), .org (organisation), .net, .edu (education), .gov (US govt); country code — .in (India), .uk, .us. Bharat sarkar ki sites: .gov.in, .nic.in. Duniya me domain/IP vyavastha ICANN dekhta hai; .in registry NIXI.

11.5 IP address, DNS, MAC

IP address = network par har device/host ki unique pehchaan (jaise ghar ka pata).
- IPv4 = 32-bit, 4 hisse dots se, har hissa 0–255: 192.168.0.178 (lagbhag 4.3 billion addresses).
- IPv6 = 128-bit, 8 groups hexadecimal, colon (:) se: 2001:CDBA:0000:0000:0000:0000:3257:9652 (lagatar zero groups "::" se chhote kar sakte hain).
- 255.255.255.0 = subnet mask (IP address nahi). CIDR (Classless Inter-Domain Routing, jaise /24) = flexible subnetting aur kushal IP allocation.
- Static IP (fixed) vs Dynamic IP (DHCP har baar deta hai). Private IPs: 192.168.x.x, 10.x.x.x.
DNS (Domain Name System) = domain name (google.com) ko IP address me badalna — "internet ki phonebook". Sabse upar 13 root server identities (A se M), jinhe 12 sansthayen chalati hain; anycast se duniya bhar me inke hazaron (2000+) instances hain.
MAC address = NIC (network card) me factory se daala 48-bit physical address, jaise 00:1A:2B:3C:4D:5E. Pehle 24 bits (OUI) = manufacturer ki pehchaan; aakhri 24 bits = device ka serial. IP = logical address, MAC = physical address.

11.6 Cookies

Cookie	Matlab
Cookie (general)	Website dwara browser me rakhi chhoti text file (login, cart, preferences yaad rakhne ke liye)
Session cookie	Temporary — browser band karte hi mit jaati hai
Persistent cookie	Tay samay tak rehti hai
Authentication cookie	Aap login ho, ye yaad rakhti hai
Third-party / tracking cookie	Doosri company ki; user behaviour tracking → targeted ads
Zombie cookie	Delete karne ke baad khud dobara ban jaati hai — privacy ke liye khatra

11.7 Social media

Aam feature: user profile banana aur photo/video (multimedia) share karna, like, comment, follow.
Microblogging = chhote posts — Twitter (ab X, 2023 se). Facebook (2004), YouTube (video), Instagram (photo/reels), LinkedIn (professional networking), WhatsApp (messaging — end-to-end encrypted chats).
Targeted ads — user behaviour tracking aur cookies se.
Naitik (ethical) samasyayen: fake news / misinformation, privacy ka ullanghan, cyberbullying, deepfake, trolling.

⚠️ Exam Traps:

Internet ≠ WWW. WWW internet ki ek service hai.
Bing = Microsoft (Google/Yahoo nahi). PageRank & Featured Snippets = Google.
URL me port optional; protocol batane wala hissa = scheme.
IPv4 dots (.) + 32 bit; IPv6 colons (:) + 128 bit. 255.255.255.0 subnet mask hai.
Root DNS = 13 (identities A–M), 12 operators.
MAC ke pehle 24 bits = manufacturer.
Delete ke baad wapas aane wali = zombie cookie.
Pehla graphical lokpriya browser = Mosaic (Chrome nahi).

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. बिंग का सर्च इंजन किस कंपनी द्वारा विकसित और मेंटेन किया जाता है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) Google

(B) Microsoft

(C) Yahoo

(D) Amazon

सही उत्तर: (B) Microsoft

Q2. URL का कौन-सा भाग ऑप्शनल (वैकल्पिक) होता है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) Scheme

(B) Host

(C) Port number

(D) Domain name

सही उत्तर: (C) Port number
Port na likhne par browser default port (80/443) le leta hai.

Q3. डोमेन नेम रिज़ॉल्यूशन के लिए दुनिया भर में कितने रूट DNS सर्वर मौजूद हैं? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) 10

(B) 13

(C) 32

(D) Unlimited

सही उत्तर: (B) 13
root-servers.org: 13 root server identities (A–M), 12 operators; physical instances hazaron me.

Q4. कौन-सा फ़ीचर Chrome और Firefox को नेटिव ऐप्स इंस्टॉल किए बिना वेब ऐप्स चलाने की अनुमति देता है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) AppCache

(B) WebAssembly

(C) Virtual DOM

(D) Progressive Web Apps (PWA)

सही उत्तर: (D) PWA

Q5. गूगल के सर्च रैंकिंग सिस्टम से मुख्य रूप से कौन-सा एल्गोरिदम जुड़ा हुआ है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) PageRank

(B) RankNet

(C) HITS

(D) SALSA

सही उत्तर: (A) PageRank

Q6. ज़्यादातर सोशल मीडिया प्लेटफ़ॉर्म पर कौन-सा फ़ीचर आम है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) Sabhi posts ke liye end-to-end encryption

(B) User profile banane aur multimedia content share karne ki suvidha

(C) Anivarya paid subscription

(D) Users ke beech koi interaction nahi

सही उत्तर: (B)

Q7. किसे सोशल मीडिया में एक बड़ा नैतिक मुद्दा माना जाता है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) Badhi hui bandwidth

(B) Fake news aur misinformation

(C) HTTPS protocol ka upyog

(D) Profile customization

सही उत्तर: (B) Fake news aur galat jaankari

Q8. निम्नलिखित में से कौन-सा IPv6 एड्रेस का सही निरूपण है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) 192.168.0.178

(B) 2001:CDBA:0000:0000:0000:0000:3257:9652

(C) 255.255.255.0

(D) 2001.3257.9652.0000

सही उत्तर: (B)
IPv6 = 8 hex groups, colon se alag. (A) IPv4, (C) subnet mask, (D) galat format.

Q9. वेब पेज को तेज़ी से लोड करने के लिए Chrome और Firefox दोनों कौन से प्रोटोकॉल अपग्रेड को सपोर्ट करते हैं? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) HTTP/1.1

(B) HTTP/2 and HTTP/3

(C) FTP

(D) SMTP

सही उत्तर: (B) HTTP/2 and HTTP/3

Q10. एक IP एड्रेस मुख्य रूप से किसे पहचानता है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) Website ka domain name

(B) Network par ek unique device ya host

(C) Web page ka title

(D) Browser session

सही उत्तर: (B)

Q11. किस सर्च इंजन ने तुरंत जवाब के लिए "फ़ीचर्ड स्निपेट्स" पेश किया? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) Bing

(B) Google

(C) Yahoo

(D) DuckDuckGo

सही उत्तर: (B) Google

Q12. IP एड्रेसिंग में CIDR का क्या उद्देश्य है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) IP packets encrypt karna

(B) Flexible subnetting aur kushal IP allocation

(C) IP ko MAC me badalna

(D) DNS records define karna

सही उत्तर: (B)
IP → MAC badalna ARP ka kaam hai; encryption IPsec ka.

Q13. सुरक्षित ब्राउज़िंग के लिए Chrome और Firefox दोनों में कौन-सा फ़ीचर समान है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) Built-in VPN

(B) Sandboxing and HTTPS enforcement

(C) Proprietary encryption algorithm

(D) Extensions ke liye support nahi

सही उत्तर: (B)

Q14. कौन-सी विशेषता सोशल मीडिया प्लेटफ़ॉर्म को लक्षित (targeted) विज्ञापन दिखाने की अनुमति देती है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) End-to-end encryption

(B) User behavior tracking and cookies

(C) Users dwara manual ad placement

(D) Randomized ad display

सही उत्तर: (B)

Q15. किस प्रकार की कुकी डिलीट होने के बाद स्वयं को पुनः उत्पन्न कर सकती है, जिससे प्राइवेसी का खतरा होता है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) Session cookie

(B) Authentication cookie

(C) Zombie cookie

(D) Magic cookie

सही उत्तर: (C) Zombie cookie

Q16. निम्नलिखित में से कौन-सा माइक्रोब्लॉगिंग प्लेटफ़ॉर्म का एक उदाहरण है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) Facebook

(B) Twitter (X)

(C) LinkedIn

(D) Pinterest

सही उत्तर: (B) Twitter (X)

Q17. URL का कौन-सा हिस्सा प्रोटोकॉल बताता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) Domain name

(B) Scheme

(C) Path

(D) Query string

सही उत्तर: (B) Scheme (jaise https://)

Q18. किस ब्राउज़र ने ग्राफ़िकल यूज़र इंटरफ़ेस की अवधारणा प्रस्तुत की और इंटरनेट को लोकप्रिय बनाया? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) Mosaic

(B) Chrome

(C) Safari

(D) Opera

सही उत्तर: (A) Mosaic (NCSA, 1993)

Q19. MAC एड्रेस का कौन-सा हिस्सा नेटवर्क इंटरफ़ेस कार्ड (NIC) के मैन्युफैक्चरर की पहचान करता है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Last 24 bits

(B) First 24 bits

(C) Last 12 bits

(D) First 12 bits

सही उत्तर: (B) First 24 bits (OUI — Organizationally Unique Identifier)

Q20. Chrome और Firefox में कौन-सा फ़ीचर वेब पेजों को अलग करता है ताकि मैलिशियस कोड पूरे ब्राउज़र को प्रभावित न कर सके? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Multi-threading

(B) Sandboxing

(C) Virtualization

(D) DNS caching

सही उत्तर: (B) Sandboxing

✍️ Practice MCQs (self-made — PYQ nahi)

P1. IPv4 address kitne bits ka hota hai? Practice MCQ

(A) 16

(B) 32

(C) 64

(D) 128

उत्तर: (B) 32 (IPv6 = 128)

P2. World Wide Web ka avishkar kisne kiya? Practice MCQ

(A) Vint Cerf

(B) Tim Berners-Lee

(C) Bill Gates

(D) Ray Tomlinson

उत्तर: (B) Tim Berners-Lee (1989, CERN)

P3. Domain name ko IP address me kaun badalta hai? Practice MCQ

(A) DHCP

(B) FTP

(C) DNS

(D) SMTP

उत्तर: (C) DNS

📌 12. ईमेल (Email) (5 min read)

Email (Electronic Mail) — pehla network email Ray Tomlinson, 1971; unhone hi @ chinh ka use shuru kiya.
Address format: username@domain, jaise anjali.si@gmail.com (username = anjali.si, domain = gmail.com).
Webmail: Gmail (Google), Outlook/Hotmail (Microsoft; Hotmail ke co-founder Sabeer Bhatia), Yahoo Mail. Sarkari: NIC email (@nic.in / @gov.in).

Field / Folder	Matlab
To	Mukhya prapt-karta
CC (Carbon Copy)	Copy — sab recipients ko ye address dikhta hai
BCC (Blind Carbon Copy)	Copy — BCC wale address doosron ko nahi dikhte
Subject / Body / Attachment (📎)	Vishay / sandesh / saath judi file
Reply / Reply All / Forward	Sirf bhejne wale ko / sabko / kisi naye vyakti ko aage bhejna
Inbox / Outbox / Sent / Drafts / Trash	Aaye mail / bhejne ki kataar / bheje gaye / adhoore / delete kiye
Spam / Junk	Bina maange bulk/fraud mail

Email protocols

Protocol	Kaam	Port
SMTP (Simple Mail Transfer Protocol)	Email bhejna (server tak/server-to-server)	25 (submission 587)
POP3 (Post Office Protocol v3)	Email download karta hai aur aam taur par server se delete kar deta hai — ek hi device ke liye	110 (SSL: 995)
IMAP (Internet Message Access Protocol)	Email server par hi rakhta hai, sab devices me sync	143 (SSL: 993)

Surakshit email transmission: SSL/TLS over SMTP (SMTPS/STARTTLS), IMAPS, POP3S. (HTTPS web pages ke liye hai; FTP file ke liye.)
SNMP (Simple Network Management Protocol) — network devices ki monitoring; email protocol nahi.

⚠️ Exam Traps:

Bhejna = SMTP; laana = POP3/IMAP. Server par rakhna = IMAP; download karke hataana = POP3.
Chhupe hue recipients = BCC.
SMTP vs SNMP — spelling par dhyan; SNMP email ka nahi.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. कौन-सा प्रोटोकॉल सर्वर से ईमेल डाउनलोड करता है और आमतौर पर प्राप्त करने के बाद उन्हें सर्वर से डिलीट कर देता है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 2

(A) SMTP

(B) POP3

(C) IMAP

(D) HTTP

सही उत्तर: (B) POP3

Q2. निम्नलिखित में से कौन ईमेल डेटा का सुरक्षित ट्रांसमिशन सुनिश्चित करता है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) HTTP

(B) HTTPS

(C) SSL/TLS over SMTP

(D) FTP

सही उत्तर: (C) SSL/TLS over SMTP
Email SMTP se jaata hai; use SSL/TLS se encrypt karna = surakshit email. HTTPS web browsing ke liye hai.

Q3. निम्नलिखित में से कौन-सा एक वैध ईमेल प्रोटोकॉल नहीं है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) SMTP

(B) POP3

(C) IMAP

(D) SNMP

सही उत्तर: (D) SNMP — network management protocol.

Q4. ईमेल सर्वर से ईमेल प्राप्त करने और उन्हें सर्वर पर ही रखने के लिए किस प्रोटोकॉल का उपयोग किया जाता है? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) POP3

(B) IMAP

(C) SMTP

(D) HTTP

सही उत्तर: (B) IMAP

Q5. ईमेल में कौन-सा फ़ील्ड दूसरे लोगों को उनका एड्रेस दिखाए बिना अतिरिक्त रिसीवर को कॉपी भेजने की अनुमति देता है? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 2

(A) CC

(B) To

(C) BCC

(D) Reply-To

सही उत्तर: (C) BCC

✍️ Practice MCQs (self-made — PYQ nahi)

P1. Email bhejne ke liye mukhya roop se kaunsa protocol use hota hai? Practice MCQ

(A) POP3

(B) IMAP

(C) SMTP

(D) FTP

उत्तर: (C) SMTP

P2. Email address me "@" ka prayog sabse pehle kisne kiya? Practice MCQ

(A) Tim Berners-Lee

(B) Ray Tomlinson

(C) Sabeer Bhatia

(D) Vint Cerf

उत्तर: (B) Ray Tomlinson

📌 13. नेटवर्किंग (Computer Networking) (9 min read)

13.1 Network ke prakar (area ke hisaab se)

Type	Area	Udaharan
PAN (Personal Area Network)	Kuch meter (≈10 m)	Bluetooth se phone-earbuds
LAN (Local Area Network)	Ek kamra / building / campus	Office, school, police thana ka network (Ethernet, Wi-Fi)
MAN (Metropolitan Area Network)	Ek shahar	City cable TV network, shahar ke bank branches
WAN (Wide Area Network)	Desh / duniya	Internet (sabse bada WAN), CCTNS jaisa rashtriya network

Size kram: PAN < LAN < MAN < WAN. Architecture: Client-Server (ek central server) vs Peer-to-Peer (sab barabar).

13.2 Topology (network ka dhancha)

Topology	Banawat	Khaas baat
Bus	Sab ek hi main cable (backbone) se	Sasta; main cable toota to poora network band; dono sire par terminator
Star	Sab ek central hub/switch se	Sabse common; ek computer kharab to baaki chalte; hub/switch kharab to sab band
Ring	Gol ghera, data ek disha me	Token passing
Mesh	Har device har doosre se juda	Sabse reliable, mehnga; n devices ke full mesh me n(n−1)/2 links
Tree	Star + Bus ka hierarchy roop	Bade organisations
Hybrid	Do ya zyada topology ka mel	—

13.3 Network devices

Device	Kaam
NIC (Network Interface Card)	Computer ko network se jodne wala card; MAC address isi me
Hub	Data ko sabhi ports par bhejta hai (dumb, broadcast)
Switch	LAN ke andar kai devices jodna; data sirf sahi device (MAC address) ko — smart
Router	Alag-alag networks ko jodna (jaise ghar ka LAN ↔ internet); IP address ke aadhar par raasta chunna
Modem (Modulator-Demodulator)	Digital ↔ Analog signal badalna; ISP se jodna. Prakar: Dial-up, DSL (phone line), Cable, Satellite, Cellular (4G/5G)
Wireless Router	Router + built-in wireless access point + Ethernet switch (ghar ka Wi-Fi router)
Access Point	Wired network me Wi-Fi jodna
Repeater	Kamzor signal ko dobara taqatwar karna (regenerate)
Bridge	Do LAN segments jodna
Gateway	Alag protocols wale networks ke beech "translator"
Firewall	Aane-jaane wale traffic ko rules ke hisaab se rokna/jaane dena (security)

Simple modem ki kami (router ke muqable): isme NAT (Network Address Translation), Wi-Fi, traffic management aur multi-device support nahi hota — ek hi device ko jodta hai.

13.4 Transmission media aur modes

Wired: Twisted pair (Ethernet — RJ45; telephone — RJ11), Coaxial (cable TV), Optical fibre (light signals, total internal reflection; sabse tez, lambi doori, interference nahi).
Wireless: Radio waves (Wi-Fi, Bluetooth), Microwave, Infrared (TV remote), Satellite.
Wi-Fi (IEEE 802.11) — mukhya bands 2.4 GHz (zyada doori, kam speed) aur 5 GHz (zyada speed, kam doori); naye Wi-Fi 6E/7 me 6 GHz bhi. Bluetooth (IEEE 802.15.1) — 2.4 GHz, chhoti doori. Ethernet = IEEE 802.3 (wired LAN).
Transmission modes: Simplex — ek disha (keyboard→CPU, TV/radio broadcast); Half-duplex — dono disha par ek samay me ek (walkie-talkie); Full-duplex — dono disha ek saath (mobile phone call).
Bandwidth = data rate, bps (bits per second) me — Kbps, Mbps, Gbps.

13.5 OSI Model (7 layers) aur TCP/IP

#	OSI Layer	Kaam / Udaharan
7	Application	User ke apps ke liye services — HTTP, FTP, SMTP, DNS
6	Presentation	Data format, encryption, compression
5	Session	Session shuru/band karna
4	Transport	End-to-end delivery — TCP (reliable), UDP (tez)
3	Network	IP address, routing — Router
2	Data Link	MAC address — Switch, Bridge
1	Physical	Cable, signal, bits — Hub, Repeater

Yaad karne ki trick (neeche se upar 1→7): "Please Do Not Throw Sausage Pizza Away" = Physical, Data Link, Network, Transport, Session, Presentation, Application. OSI model ISO ne banaya. TCP/IP model me 4 layers: Network Access (Link), Internet, Transport, Application.

⚠️ Exam Traps:

LAN ke andar devices jodna = Switch; networks jodna = Router.
Phone line se ISP = DSL modem; cable TV line = cable modem.
Wi-Fi + switch ek dabbe me = Wireless router.
Wi-Fi bands = 2.4 GHz & 5 GHz (900 MHz/1.8 GHz mobile network bands hain).
Router = Layer 3; Switch = Layer 2; Hub = Layer 1.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. कौन-सा मॉडेम टाइप DSL एक्सेस का इस्तेमाल करके फ़ोन लाइनों के ज़रिए ISP से कनेक्ट होता है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) Cable modem

(B) Satellite modem

(C) DSL modem

(D) Cellular modem

सही उत्तर: (C) DSL modem (DSL = Digital Subscriber Line)

Q2. राउटर की तुलना में एक सिंपल मॉडेम का आम नुकसान क्या है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) Isme NAT, Wi-Fi, traffic management aur multi-device support ki kami hoti hai

(B) Sirf Layer 3 par kaam karta hai

(C) Analog signal modulate nahi kar sakta

(D) Satellite communication chahiye

सही उत्तर: (A)
Modulation to modem ka mool kaam hai, isliye (C) galat.

Q3. LAN के अंदर कई डिवाइस को कनेक्ट करने और कम्युनिकेशन व डेटा शेयरिंग के लिए आमतौर पर किस डिवाइस का इस्तेमाल होता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) Router

(B) Switch

(C) Modem

(D) Firewall

सही उत्तर: (B) Switch

Q4. आमतौर पर किस डिवाइस में बिल्ट-इन वायरलेस एक्सेस पॉइंट और ईथरनेट स्विच होता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Satellite modem

(B) Wireless router

(C) Core router

(D) DSL modem

सही उत्तर: (B) Wireless router

Q5. वाई-फ़ाई में आमतौर पर कौन-से फ़्रीक्वेंसी बैंड इस्तेमाल होते हैं? MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) 900 MHz and 1.8 GHz

(B) 2.4 GHz and 5 GHz

(C) 10 GHz and 20 GHz

(D) 60 GHz only

सही उत्तर: (B) 2.4 GHz and 5 GHz

✍️ Practice MCQs (self-made — PYQ nahi)

P1. Kis topology me sabhi computer ek central hub/switch se jude hote hain? Practice MCQ

(A) Bus

(B) Ring

(C) Star

(D) Mesh

उत्तर: (C) Star

P2. 5 computers ke full mesh network me kitne links chahiye? Practice MCQ

(A) 5

(B) 10

(C) 20

(D) 25

उत्तर: (B) 10 — n(n−1)/2 = 5×4/2 = 10.

P3. OSI model me router kis layer par kaam karta hai? Practice MCQ

(A) Physical

(B) Data Link

(C) Network

(D) Transport

उत्तर: (C) Network (Layer 3)

P4. Walkie-talkie kis transmission mode ka udaharan hai? Practice MCQ

(A) Simplex

(B) Half-duplex

(C) Full-duplex

(D) Multiplex

उत्तर: (B) Half-duplex

📌 14. प्रोटोकॉल एवं पोर्ट (Protocols & Ports) (5 min read)

Protocol = computers ke beech baat-cheet ke niyam (rules). Har service ka ek default port number hota hai.

Protocol	Full form	Kaam	Default port
HTTP	HyperText Transfer Protocol	Web pages (bina encryption)	80
HTTPS	HTTP Secure	Encrypted web (SSL/TLS) — 🔒 padlock; banking/login ke liye zaroori	443
FTP	File Transfer Protocol	Files upload/download (bina encryption)	20, 21
SFTP	SSH File Transfer Protocol	Surakshit (encrypted) file transfer	22 (SSH)
SSH / Telnet	Secure Shell / —	Remote login (SSH encrypted; Telnet nahi)	22 / 23
SMTP	Simple Mail Transfer Protocol	Email bhejna	25
POP3 / IMAP	Post Office Protocol / Internet Message Access Protocol	Email prapt karna	110 / 143
DNS	Domain Name System	Naam → IP	53
DHCP	Dynamic Host Configuration Protocol	Devices ko automatic IP dena	67/68
SNMP	Simple Network Management Protocol	Network devices monitor karna	161
TCP	Transmission Control Protocol	Connection-oriented, reliable (web, email, file)	—
UDP	User Datagram Protocol	Connectionless, tez (video streaming, online games, DNS)	—
IP	Internet Protocol	Addressing aur routing	—
ARP	Address Resolution Protocol	IP → MAC address	—

⚠️ Exam Traps:

Sensitive jaankari (password, card) daalne se pehle URL me HTTPS aur 🔒 dekhein.
Server par surakshit upload = SFTP (sada FTP/HTTP encrypted nahi; POP3 email ka hai).
HTTP = 80, HTTPS = 443 — ulta na karein.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. फ़ाइलों को सर्वर पर अपलोड करने का सबसे सुरक्षित तरीका कौन-सा है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) FTP without encryption

(B) SFTP

(C) HTTP

(D) POP3

सही उत्तर: (B) SFTP — SSH ke through encrypted file transfer.

Q2. ऑनलाइन संवेदनशील जानकारी दर्ज करने से पहले आपको URL में कौन-सा प्रोटोकॉल हमेशा चेक करना चाहिए? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) FTP

(B) HTTP

(C) HTTPS

(D) SMTP

सही उत्तर: (C) HTTPS

✍️ Practice MCQs (self-made — PYQ nahi)

P1. HTTPS ka default port number? Practice MCQ

(A) 21

(B) 25

(C) 80

(D) 443

उत्तर: (D) 443

P2. Network me devices ko automatically IP address kaun deta hai? Practice MCQ

(A) DNS

(B) DHCP

(C) FTP

(D) ARP

उत्तर: (B) DHCP

📌 15. साइबर सुरक्षा (Cyber Security) — Malware, Attacks, Antivirus (10 min read)

15.1 Malware (Malicious Software) ke prakar

Malware	Pehchaan
Virus (exam books me "Vital Information Resources Under Seize" likha milta hai — ye baad me bana lokpriya expansion hai, asli acronym nahi)	Kisi file/program se chipak kar failta hai; chalane (user action) par active. Pehla PC virus "Brain" (1986, Pakistan)
Worm	Khud apni copies bana kar network par failta hai; host file ki zaroorat nahi
Trojan Horse	Asli/upyogi software ka roop dharkar user ko install karne ke liye dhokha deta hai; peechhe se nuksaan
Ransomware	Data ko encrypt/lock karke wapas dene ke liye paisa (phirauti) maangta hai — jaise WannaCry (2017)
Spyware	Chupke se jaankari chura kar bhejta hai
Keylogger	Keyboard par dabayi har key (password) record karta hai
Adware	Zabardasti ads dikhata hai
Rootkit / Backdoor	Gehraai me chhup kar hacker ko chupa raasta deta hai
Botnet	Infected "zombie" computers ka network — DDoS attack me use
Logic bomb	Tay shart/tareekh par active hone wala code

15.2 Cyber attacks aur thagi (fraud)

Attack	Matlab
Phishing	Nakli email/website se password, OTP, bank details churana
Vishing / Smishing	Voice call se / SMS se phishing
Pharming	DNS badal kar asli URL par bhi nakli site par le jaana
Spoofing	Nakli pehchaan (email ID, caller ID, IP)
DoS / DDoS	Server par itni requests ki wo band ho jaaye (DDoS = kai computers/botnet se)
Man-in-the-Middle (MITM)	Do logon ke beech chupke se data padhna/badalna — public Wi-Fi par khatra
SQL Injection	Website ke form me malicious code daal kar database tak pahunchna
Brute force / Dictionary attack	Lakhon passwords try karna
Rainbow table	Pehle se compute kiye password hashes ki table se password todna. Bachav: har password ke liye unique random salt (salting) — global salt se kam suraksha
Social engineering	Insaan ko baaton me fansa kar jaankari lena (bank/KYC/police ban kar call)
SIM swap, Juice jacking, QR code scam	Duplicate SIM se OTP lena; public USB charging port se data chori; QR scan karwa kar paisa katna
"Digital arrest" scam	Fraudster video call par police/CBI ban kar "arrest" ki dhamki deta hai — kanoon me "digital arrest" jaisi koi vyavastha nahi; turant 1930 par report
Malware injection (file upload)	Website par file upload ke dauran malicious file daal dena — upload ka aam jokhim

15.3 Hackers ke prakar

White hat = ethical hacker — anumati lekar security kamiyan dhoondh kar theek karwata hai.
Black hat = criminal hacker (nuksaan/chori). Grey hat = beech wala — bina anumati ghusta hai par bura irada zaroori nahi. Cracker = security tod kar galat kaam karne wala.

15.4 Bachav (Security measures)

Firewall — network aur computer ke beech "deewar"; aane-jaane wale traffic ko rules ke hisaab se allow/block (hardware ya software).
Antivirus detection methods:
- Signature-based — file ko jaane-pehchaane virus ke signatures (database) se milana; naya virus pakadne ke liye update zaroori.
- Heuristic analysis — suspicious program ke source code/behaviour patterns ko heuristic database ke known malware patterns se milana; naye/badle roop pakadta hai.
- Sandbox detection — suspicious file ko virtual environment (sandbox) me chala kar dekhna kya karti hai.
- Data mining techniques — machine learning se file ko malicious ya safe classify karna (advanced method).
- Real-time protection — file khulte/download hote hi turant scan.
Indian antivirus: Quick Heal (Pune). Anya: Microsoft Defender, Norton, McAfee, Kaspersky.
Authentication: strong password, 2FA/MFA (kuch jo aap jaante ho — password; kuch jo aapke paas hai — OTP/phone; kuch jo aap ho — fingerprint), CAPTCHA (insaan hai ya bot).
Encryption — plaintext → ciphertext. Symmetric (ek hi key — AES) vs Asymmetric (public + private key — RSA). Digital signature, SSL/TLS certificate, end-to-end encryption.
Safe habits: public Wi-Fi par password/banking details na daalein (ya VPN use karein); "Install antivirus" wale pop-up ke button par click na karein — pop-up button ke bajaye 'X' se band karein (zarurat ho to Alt + F4/Task Manager); OS/apps update rakhein; OTP/PIN kisi ko na batayen; URL me HTTPS dekhein; unknown links/APK na kholein.

⚠️ Exam Traps:

Paisa maange = Ransomware; asli software ka roop = Trojan; khud faile = Worm.
Ethical hacker = White hat.
Virtual environment me chalana = Sandbox; ML classification = Data mining; code patterns vs heuristic database = Heuristic; known signatures = Signature-based.
Rainbow table se bachav = unique random salt per password.
Public Wi-Fi par firewall band karna / HTTP sites use karna = galat.

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. फ़ाइल अपलोड के दौरान इनमें से कौन-सा एक आम जोखिम है? MPESB SI Prelims 2025 — 16 Jan 2026, Shift 1

(A) Increased bandwidth

(B) Malware injection

(C) HTTPS encryption

(D) DNS resolution

सही उत्तर: (B) Malware injection

Q2. कौन-सा मैलवेयर यूज़र डेटा तक पहुंच बहाल करने के लिए पेमेंट की मांग करता है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 1

(A) Spyware

(B) Ransomware

(C) Worm

(D) Adware

सही उत्तर: (B) Ransomware

Q3. किस तरह का हैकर सुरक्षा की कमियों को ठीक करने के लिए नैतिक रूप से कार्य करता है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) Black hat

(B) Grey hat

(C) White hat

(D) Crackers

सही उत्तर: (C) White hat

Q4. बल्क पासवर्ड क्रैकिंग के लिए हमलावरों को हैश (रैनबो टेबल) पहले से कम्प्यूट करने से रोकने का सबसे प्रभावी तरीका कौन-सा है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) Sabhi passwords ko AES se encrypt karein

(B) Sabhi passwords ke liye global salt

(C) Har password ke liye unique random salt

(D) Sirf hashing

सही उत्तर: (C) Unique random salt per password
Har password ka salt alag hone se ek precomputed table sab par kaam nahi karti.

Q5. कौन-सा मैलवेयर यूज़र्स को धोखा देने के लिए खुद को असली सॉफ़्टवेयर के रूप में छिपाता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Worm

(B) Trojan

(C) Virus

(D) Ransomware

सही उत्तर: (B) Trojan

Q6. एंटीवायरस डिटेक्शन का कौन-सा तरीका संदिग्ध फ़ाइलों को वर्चुअल एनवायरनमेंट में चलाता है? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 2

(A) Signature-based

(B) Sandbox detection

(C) Heuristic

(D) Real-time protection

सही उत्तर: (B) Sandbox detection

Q7. कौन-सा एडवांस्ड एंटीवायरस तरीका मैलवेयर क्लासिफिकेशन के लिए मशीन लर्निंग का इस्तेमाल करता है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Heuristic analysis

(B) Data mining techniques

(C) Signature-based detection

(D) Real-time protection

सही उत्तर: (B) Data mining techniques
Antivirus ke naye tareeke me data mining/machine learning algorithms file ke behaviour ko malicious ya benign classify karte hain.

Q8. संवेदनशील कार्यों के लिए सार्वजनिक वाई-फ़ाई का इस्तेमाल करते समय कौन-सा तरीका जोखिम को कम करता है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Firewall band karein

(B) Public network par password ya banking details daalne se bachein

(C) Cookies enable karein

(D) HTTP websites use karein

सही उत्तर: (B)

Q9. जब कोई पॉप-अप आपको एंटीवायरस सॉफ़्टवेयर इंस्टॉल करने के लिए कहे, तो आपको क्या करना चाहिए? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Turant "Install" par click

(B) Pop-up button ke bajaye 'X' icon se band karein

(C) Accept karke scan karein

(D) Andekha karke browsing jaari rakhein

सही उत्तर: (B)
Aise pop-up aksar "scareware" hote hain; unke andar ke kisi button (OK/Install/Cancel) par click karna khatarnaak ho sakta hai.

Q10. कौन-सा एंटीवायरस तरीका सोर्स कोड पैटर्न की तुलना ह्यूरिस्टिक डेटाबेस में जाने-पहचाने मैलवेयर से करता है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) Signature-based detection

(B) Sandbox detection

(C) Heuristic analysis

(D) Data mining

सही उत्तर: (C) Heuristic analysis

✍️ Practice MCQs (self-made — PYQ nahi)

P1. SMS ke through ki gayi phishing ko kya kehte hain? Practice MCQ

(A) Vishing

(B) Smishing

(C) Pharming

(D) Spoofing

उत्तर: (B) Smishing

P2. Jo malware bina kisi host file ke network par khud apni copies bana kar failta hai? Practice MCQ

(A) Virus

(B) Trojan

(C) Worm

(D) Adware

उत्तर: (C) Worm

P3. Keyboard par type kiye gaye password ko chupke se record karne wala software? Practice MCQ

(A) Keylogger

(B) Firewall

(C) Cookie

(D) Compiler

उत्तर: (A) Keylogger

📌 16. बैकअप एवं क्लाउड स्टोरेज (Backup & Cloud Storage) (6 min read — 2025 me 8 PYQ!)

16.1 Backup ke prakar

Backup	Kya copy hota hai	Storage	Restore
Full	Har baar saara data	Sabse zyada	Sabse aasaan/tez (ek hi set)
Incremental	Pichhle kisi bhi backup (full ya incremental) ke baad badli files	Sabse kam	Sabse dheema — full + saare incrementals chahiye
Differential	Pichhle full backup ke baad badli saari files (beech ke incrementals se farq nahi padta)	Beech ka (roz badhta)	Full + aakhri differential
Mirror	Source ki hubahu copy (source se delete to mirror se bhi)	—	—
Hybrid	Local (on-premises) + Cloud dono ka mel	—	Local se tez, cloud se aapda me bhi surakshit
CDP (Continuous Data Protection)	Har write/badlav real time me record	—	Kisi bhi pal ka data wapas
Snapshot	Kisi samay ki "photo" (point-in-time image)	—	—

3-2-1 rule: data ki 3 copies, 2 alag media par, 1 copy offsite (door/cloud).
RAID (Redundant Array of Independent Disks) = kai disks ko jod kar speed/redundancy — ye akele poora backup nahi hai.

16.2 Cloud storage ke prakar

Type	Data model	Access	Use
Object storage	Flat namespace; har object ke saath unique object ID + rich metadata; update par poora object dobara likha jaata hai	API (HTTP/REST) se	Videos, logs, backups, data lake — lagbhag unlimited scalability (jaise Amazon S3)
Block storage	Data fixed-size blocks me; volume/disk ki tarah	SAN; OS ise disk ki tarah dekhta hai	Databases, virtual machines (kam latency)
File storage	Hierarchical folders/paths	NAS; file-share protocols	Shared office folders

Tape libraries = sasta archival storage (sequential access, dheema).

⚠️ Exam Traps:

"Since last full backup" = Differential. "Least storage, longest restore" = Incremental.
Local + cloud = Hybrid. Real-time har badlav = CDP.
Flat namespace + unique ID + metadata + REST API = Object storage. Hierarchical paths = file storage (block nahi).

🎯 PYQs — Official MPESB SI Prelims 2025 paper

Q1. कौन-सी बैकअप रणनीति लोकल (ऑन-प्रिमाइसेस) और क्लाउड-आधारित बैकअप समाधान दोनों के तत्वों को जोड़ती है? MPESB SI Prelims 2025 — 17 Jan 2026, Shift 2

(A) RAID

(B) Hybrid backup

(C) Mirror backup

(D) Continuous backup

सही उत्तर: (B) Hybrid backup

Q2. वीडियो और लॉग के डेटा लेक को लगभग अनलिमिटेड स्केलेबिलिटी और रिच मेटाडेटा की ज़रूरत है, साथ ही यह रीराइट-ऑन-अपडेट (पूरे ऑब्जेक्ट का राइट) को भी सपोर्ट करे। कौन-सा स्टोरेज सबसे सही रहेगा? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 1

(A) NAS file shares

(B) Object storage

(C) SAN block volumes

(D) Tape libraries

सही उत्तर: (B) Object storage

Q3. कौन-सा स्टेटमेंट Continuous Data Protection (CDP) के व्यवहार को सही ढंग से दिखाता है? MPESB SI Prelims 2025 — 18 Jan 2026, Shift 2

(A) Roz full aur har ghante differential

(B) Sirf tay samay (jaise daily) par snapshots

(C) Sirf aakhri backup point tak recovery

(D) Har write/badlav real time me record, kisi bhi pal ka restore

सही उत्तर: (D)

Q4. कौन-सा बैकअप तरीका पिछले फुल बैकअप के बाद से बदले गए सभी फ़ाइलों को कॉपी करता है, भले ही पहले इंक्रीमेंटल बैकअप लिए गए हों? MPESB SI Prelims 2025 — 19 Jan 2026, Shift 1

(A) Differential backup

(B) Incremental backup

(C) Full backup

(D) Snapshot backup

सही उत्तर: (A) Differential backup

Q5. ऑब्जेक्ट स्टोरेज में, डेटा रिट्रीवल आमतौर पर इसका इस्तेमाल करता है: MPESB SI Prelims 2025 — 20 Jan 2026, Shift 1

(A) File path traversal

(B) Block address mapping

(C) API ke madhyam se metadata ke saath unique object ID

(D) Direct inode reference

सही उत्तर: (C)

Q6. किस बैकअप टाइप में सबसे कम स्टोरेज स्पेस लगता है, लेकिन रिस्टोर करने में सबसे ज़्यादा समय लगता है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 1

(A) Full backup

(B) Incremental backup

(C) Differential backup

(D) Continuous backup

सही उत्तर: (B) Incremental backup

Q7. क्लाउड स्टोरेज आर्किटेक्चर में, डेटा मॉडल और विशिष्ट एक्सेस मैकेनिज्म के साथ कौन-सी पेयरिंग सबसे अच्छी तरह मेल खाती है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) Block storage — hierarchical paths aur POSIX file calls

(B) Object storage — flat namespace aur API access (HTTP/REST)

(C) File storage — unique object IDs aur metadata-driven retrieval

(D) Block storage — globally unique identifiers aur per-object metadata

सही उत्तर: (B)
Baaki options me features galat storage type se jode gaye hain.

Q8. कौन-सा बैकअप तरीका पिछले फुल बैकअप के बाद से बदले गए फ़ाइलों को ही स्टोर करता है? MPESB SI Prelims 2025 — 21 Jan 2026, Shift 2

(A) Full backup

(B) Incremental backup

(C) Differential backup

(D) Mirror backup

सही उत्तर: (C) Differential backup
Incremental = pichhle kisi bhi backup ke baad; Differential = pichhle full backup ke baad.

📌 17. साइबर अपराध एवं IT Act 2000 (Cyber Crime & Law) (6 min read)

17.1 Information Technology Act, 2000

India ka mukhya cyber kanoon. Act No. 21 of 2000. Rashtrapati ki sweekriti 9 June 2000; lagu 17 October 2000.
Uddeshya: electronic transactions (e-commerce), electronic records aur digital signature ko kanooni manyata; cyber apradhon ke liye dand.
IT (Amendment) Act 2008 — 27 October 2009 se lagu; isne Section 66A–66F, 67A, 67B jode aur "digital signature" ki jagah "electronic signature" ki vyapak dharna di.

Section	Apradh / Pravdhan
43	Bina anumati computer/data ko nuksaan — muavza (compensation)
65	Computer source code/documents se chhedchhaad
66	Computer-related offences (hacking) — 3 saal tak / ₹5 lakh tak
66A	"Offensive messages" — Supreme Court ne Shreya Singhal v. Union of India (24 March 2015) me radd (struck down) kiya — Article 19(1)(a) ka ullanghan
66B	Chori ka computer/mobile beimaani se rakhna
66C	Identity theft — doosre ka password, OTP, electronic signature istemal karna
66D	Cheating by personation — computer/phone se kisi aur ban kar thagi (fake profile, fake call)
66E	Privacy ka ullanghan — kisi ki private tasveer lena/chhapna
66F	Cyber terrorism — aajeevan karawas tak
67 / 67A / 67B	Ashleel samagri / sexually explicit / bachchon se judi ashleel samagri electronic roop me
69 / 69A	Sarkar dwara interception-monitoring / website-app block karna (June 2020 me 59 apps, TikTok samet, 69A ke tahat block)
70 / 70B	Protected system / CERT-In ka pravdhan

17.2 Sansthayen aur helpline

1930 — National Cyber Crime Helpline (khaas kar financial fraud ki turant report; 24×7).
cybercrime.gov.in — National Cyber Crime Reporting Portal; I4C (Indian Cyber Crime Coordination Centre), Grih Mantralaya (MHA) ke tahat.
CERT-In (Indian Computer Emergency Response Team) — cyber incidents par rashtriya nodal agency, MeitY ke tahat.
Sanchar Saathi (Doorsanchar Vibhag) — kho gaye/chori mobile block karna, sandigdh fraud call/SMS report karna.
Digital Personal Data Protection (DPDP) Act, 2023 — sweekriti 11 August 2023; logon ke digital personal data ki suraksha.
Naye aapradhik kanoon (1 July 2024 se): IPC ki jagah BNS 2023; Evidence Act ki jagah BSA 2023 — electronic record ki admissibility ab BSA Section 63 me (pehle IEA 65B). IT Act 2000 lagu hai.

⚠️ Exam Traps:

IT Act 2000, lagu 17 Oct 2000; amendment 2008 (lagu 2009).
66C = identity theft; 66D = personation se cheating; 66F = cyber terrorism (life).
66A radd ho chuka hai (2015) — ab is par FIR nahi.
Cyber fraud helpline = 1930 (112 general emergency hai).

✍️ Practice MCQs (self-made — PYQ nahi)

P1. IT Act 2000 ka kaunsa section cyber terrorism se sambandhit hai? Practice MCQ

(A) 66A

(B) 66C

(C) 66F

(D) 67

उत्तर: (C) 66F

P2. Supreme Court ne IT Act ki kaunsi dhara Shreya Singhal case (2015) me radd ki? Practice MCQ

(A) 66A

(B) 69A

(C) 43

(D) 79

उत्तर: (A) 66A (69A ko vaidh mana)

P3. Online financial fraud ki turant shikayat ke liye rashtriya helpline number? Practice MCQ

(A) 100

(B) 181

(C) 1930

(D) 1098

P4. Kisi doosre vyakti ka password ya OTP chura kar use karna IT Act ki kis dhara me aata hai? Practice MCQ

(A) 66B

(B) 66C

(C) 66E

(D) 67

उत्तर: (B) 66C — identity theft

📌 18. संख्या पद्धति (Number System) एवं Codes (8 min read)

18.1 Chaar mukhya number systems

System	Base (आधार)	Digits	Udaharan
Binary (द्विआधारी)	2	0, 1	(1011)₂
Octal	8	0–7	(57)₈
Decimal (दशमलव)	10	0–9	(47)₁₀
Hexadecimal	16	0–9, A=10, B=11, C=12, D=13, E=14, F=15	(2F)₁₆

Computer andar sab kuch binary me samajhta hai (0 = off, 1 = on). n bits se 2ⁿ alag combinations banti hain — 8 bits se 2⁸ = 256 (0 se 255).

18.2 Conversions — step by step

Conversion	Tarika	Udaharan
Decimal → Binary	2 se baar-baar bhag do, shesh (remainders) neeche se upar padho	25 → 25÷2=12 r1, 12÷2=6 r0, 6÷2=3 r0, 3÷2=1 r1, 1÷2=0 r1 → (11001)₂
Binary → Decimal	Daayen se sthaan-maan 1, 2, 4, 8, 16, 32, 64, 128… — jahan 1 hai unhe jodo	(1011)₂ = 8+0+2+1 = 11; (101111)₂ = 32+8+4+2+1 = 47
Binary → Octal	Daayen se 3-3 bits ke group	101 111 → (57)₈
Binary → Hex	Daayen se 4-4 bits ke group	0010 1111 → (2F)₁₆
Octal/Hex → Decimal	Base ki power se guna	(57)₈ = 5×8 + 7 = 47; (2F)₁₆ = 2×16 + 15 = 47; (A5)₁₆ = 10×16 + 5 = 165
Decimal → Octal/Hex	8 ya 16 se baar-baar bhag	100 = (144)₈ = (64)₁₆ = (1100100)₂
Decimal fraction → Binary	2 se baar-baar guna, poornank (integer) upar se neeche	0.625 → 1.25 (1), 0.5 (0), 1.0 (1) → (0.101)₂

Yaad rakhein: (255)₁₀ = (11111111)₂ = (377)₈ = (FF)₁₆. (15)₁₀ = (1111)₂ = (F)₁₆. (8)₁₀ = (1000)₂ = (10)₈. (16)₁₀ = (10000)₂ = (10)₁₆.

18.3 Binary ganit

Jod: 0+0=0, 0+1=1, 1+1=10 (0 likho, 1 haasil), 1+1+1=11. Udaharan: 1011 + 0110 = 10001 (11 + 6 = 17 ✓).
Ghatana: 1010 − 0011 = 0111 (10 − 3 = 7 ✓).
1's complement = har bit ulta: 1010 → 0101. 2's complement = 1's complement + 1: 1010 → 0110 (negative numbers dikhane ke liye).

18.4 Codes

ASCII — American Standard Code for Information Interchange; 7-bit, 128 characters (extended 8-bit = 256). 'A' = 65, 'a' = 97, '0' = 48, space = 32.
Unicode — duniya ki lagbhag sabhi lipiyan (Hindi/Devanagari samet); UTF-8 web par sabse common.
EBCDIC — IBM mainframes ka 8-bit code. BCD — har decimal digit ke liye 4 bits: 25 = 0010 0101.

⚠️ Exam Traps:

Decimal → binary me remainders neeche se upar padhna hai.
Octal = 3-bit group, Hex = 4-bit group. Octal me 8 aur 9 digit nahi hote.
Hex me F = 15 (16 nahi). (10)₁₆ = 16.

✍️ Practice MCQs (self-made — PYQ nahi)

P1. (1101)₂ ka decimal maan? Practice MCQ

(A) 11

(B) 12

(C) 13

(D) 14

उत्तर: (C) 13 — 8+4+0+1.

P2. (30)₁₀ ko binary me likhen. Practice MCQ

(A) 11110

(B) 11100

(C) 10110

(D) 11011

उत्तर: (A) 11110 — 16+8+4+2 = 30.

P3. (11010110)₂ ka hexadecimal? Practice MCQ

(A) C6

(B) D6

(C) D5

(D) E6

उत्तर: (B) D6 — 1101 = D (13), 0110 = 6.

P4. (64)₈ ka decimal maan? Practice MCQ

(A) 48

(B) 52

(C) 64

(D) 54

उत्तर: (B) 52 — 6×8 + 4 = 52.

P5. Hexadecimal system ka base kya hai? Practice MCQ

(A) 2

(B) 8

(C) 10

(D) 16

उत्तर: (D) 16

📌 19. महत्वपूर्ण संक्षिप्त रूप (Important Abbreviations) (7 min read)

Hardware & Memory

Short	Full form	Short	Full form
CPU	Central Processing Unit	ALU / CU	Arithmetic Logic Unit / Control Unit
RAM	Random Access Memory	ROM	Read Only Memory
SRAM / DRAM	Static / Dynamic RAM	PROM	Programmable ROM
EPROM	Erasable Programmable ROM	EEPROM	Electrically Erasable Programmable ROM
BIOS	Basic Input/Output System	POST	Power-On Self-Test
CMOS	Complementary Metal-Oxide-Semiconductor	USB	Universal Serial Bus
HDD / SSD	Hard Disk Drive / Solid State Drive	SATA	Serial Advanced Technology Attachment
CD-ROM	Compact Disc Read Only Memory	DVD	Digital Versatile Disc
HDMI	High-Definition Multimedia Interface	VGA	Video Graphics Array
LCD / LED	Liquid Crystal Display / Light Emitting Diode	CRT	Cathode Ray Tube
OLED	Organic Light Emitting Diode	VDU	Visual Display Unit
SMPS	Switched-Mode Power Supply	UPS	Uninterruptible Power Supply
OCR	Optical Character Recognition	OMR	Optical Mark Reader/Recognition
MICR	Magnetic Ink Character Recognition	BCR	Bar Code Reader
DPI / PPM / CPS	Dots per Inch / Pages per Minute / Characters per Second	RPM	Revolutions per Minute
IC / VLSI	Integrated Circuit / Very Large Scale Integration	GPU	Graphics Processing Unit
MIPS	Million Instructions Per Second	FLOPS	Floating-point Operations Per Second

Software, Early Computers & Languages

Short	Full form	Short	Full form
OS	Operating System	DOS	Disk Operating System
GUI	Graphical User Interface	CLI	Command Line Interface
ENIAC	Electronic Numerical Integrator and Computer	UNIVAC	Universal Automatic Computer
EDSAC	Electronic Delay Storage Automatic Calculator	EDVAC	Electronic Discrete Variable Automatic Computer
FORTRAN	Formula Translation	COBOL	Common Business Oriented Language
BASIC	Beginner's All-purpose Symbolic Instruction Code	SQL	Structured Query Language
DBMS	Database Management System	CAD / CAM	Computer-Aided Design / Manufacturing
ASCII	American Standard Code for Information Interchange	EBCDIC	Extended Binary Coded Decimal Interchange Code
BCD	Binary Coded Decimal	GIGO	Garbage In, Garbage Out
PDF	Portable Document Format	JPEG	Joint Photographic Experts Group
GIF	Graphics Interchange Format	PNG	Portable Network Graphics
MPEG	Moving Picture Experts Group	CSV	Comma-Separated Values

Internet, Network & Security

Short	Full form	Short	Full form
WWW	World Wide Web	URL	Uniform Resource Locator
HTML	HyperText Markup Language	HTTP(S)	HyperText Transfer Protocol (Secure)
XML / CSS	eXtensible Markup Language / Cascading Style Sheets	ISP	Internet Service Provider
IP / TCP / UDP	Internet Protocol / Transmission Control Protocol / User Datagram Protocol	DNS	Domain Name System
FTP / SFTP	File Transfer Protocol / SSH File Transfer Protocol	DHCP	Dynamic Host Configuration Protocol
SMTP	Simple Mail Transfer Protocol	POP / IMAP	Post Office Protocol / Internet Message Access Protocol
SSL / TLS	Secure Sockets Layer / Transport Layer Security	SSH	Secure Shell
LAN / MAN / WAN / PAN	Local / Metropolitan / Wide / Personal Area Network	WLAN	Wireless LAN
NIC	Network Interface Card (aur National Informatics Centre)	MAC	Media Access Control
OSI	Open Systems Interconnection	NAT / CIDR	Network Address Translation / Classless Inter-Domain Routing
VPN	Virtual Private Network	VoIP	Voice over Internet Protocol
DSL / ADSL	Digital Subscriber Line / Asymmetric DSL	ISDN	Integrated Services Digital Network
Wi-Fi	Aam taur par "Wireless Fidelity" likha jaata hai (Wi-Fi Alliance ke anusaar ye trademark naam hai)	IEEE	Institute of Electrical and Electronics Engineers
ICANN	Internet Corporation for Assigned Names and Numbers	CAPTCHA	Completely Automated Public Turing test to tell Computers and Humans Apart
GPS	Global Positioning System	GSM	Global System for Mobile Communications
SIM	Subscriber Identity Module	IMEI	International Mobile Equipment Identity
OTP / PIN	One Time Password / Personal Identification Number	QR / RFID / NFC	Quick Response / Radio Frequency Identification / Near Field Communication
SMS / MMS	Short Message Service / Multimedia Messaging Service	DDoS	Distributed Denial of Service

Banking, e-Governance & New Tech

Short	Full form	Short	Full form
UPI	Unified Payments Interface	NPCI	National Payments Corporation of India
BHIM	Bharat Interface for Money	IMPS	Immediate Payment Service
NEFT	National Electronic Funds Transfer	RTGS	Real Time Gross Settlement
ATM	Automated Teller Machine	KYC	Know Your Customer
AI / ML	Artificial Intelligence / Machine Learning	IoT	Internet of Things
AR / VR	Augmented Reality / Virtual Reality	IaaS / PaaS / SaaS	Infrastructure / Platform / Software as a Service
CERT-In	Indian Computer Emergency Response Team	C-DAC	Centre for Development of Advanced Computing
MeitY	Ministry of Electronics and Information Technology	UIDAI	Unique Identification Authority of India
UMANG	Unified Mobile Application for New-age Governance	I4C	Indian Cyber Crime Coordination Centre
CCTNS	Crime and Criminal Tracking Network & Systems	GeM	Government e-Marketplace

📌 20. नई तकनीक, UPI एवं ई-गवर्नेंस (Latest Tech, UPI & e-Governance) (7 min read)

20.1 Cloud Computing

Internet par on-demand computing resources (server, storage, software) — jitna use, utna bhugtan; khud hardware kharidne ki zaroorat nahi.
Service models: IaaS (Infrastructure — virtual server/storage, jaise AWS EC2), PaaS (Platform — developers ke liye, jaise Google App Engine), SaaS (Software — browser me readymade software: Gmail, Google Docs, Microsoft 365).
Deployment: Public, Private, Hybrid (dono ka mel), Community. Cloud storage: Google Drive, OneDrive, Dropbox, iCloud; sarkari — DigiLocker. Bharat sarkar ki cloud pahal: MeghRaj (GI Cloud).

20.2 Artificial Intelligence (AI) aur anya

AI = machine me insaan jaisi soch/seekhne ki kshamata. Term John McCarthy (1956). Turing Test (Alan Turing, 1950) — machine insaan jaisa vyavhar karti hai ya nahi.
Machine Learning = data se khud seekhna (AI ka hissa); Deep Learning = neural networks (ML ka hissa). Generative AI = naya text/image banana — ChatGPT (OpenAI, Nov 2022), Gemini (Google). Chatbot, face recognition, voice assistant (Siri, Alexa).
Deepfake = AI se banaya nakli video/audio — cyber apradh aur fake news me khatra.
IoT (Internet of Things) = roz ki cheezein internet se judi (smart meter, smart watch, smart TV, CCTV). Term Kevin Ashton (1999).
Blockchain = decentralised, distributed digital ledger (badla nahi ja sakta); cryptocurrency (Bitcoin — "Satoshi Nakamoto"). RBI ka Digital Rupee (e₹) = CBDC, pilot 2022 me shuru.
5G — India me 1 October 2022 ko launch (PM Modi, India Mobile Congress). Bahut tez speed, kam latency.
Anya: Big Data (Volume, Velocity, Variety), Edge computing, Quantum computing (qubits), AR/VR/Metaverse, 3D printing, Drones, Robotics.

20.3 UPI aur Digital Payments

UPI (Unified Payments Interface) — NPCI ne banaya; 11 April 2016 ko RBI Governor Raghuram Rajan ne (Nandan Nilekani ke saath) launch kiya. IMPS platform ke upar bana.
Ek app me kai bank accounts; 24×7 turant transfer; UPI ID/VPA (jaise name@bank), QR code, UPI PIN. Paisa bhejne ke liye PIN chahiye — paisa lene ke liye kabhi PIN nahi daalna (fraud ki pehchaan).
BHIM app — NPCI ka UPI app (30 Dec 2016). UPI Lite (chhote payments), UPI 123PAY (feature phone). RuPay — India ka card network (NPCI).
Anya: NEFT, RTGS (bade amount), IMPS (24×7 turant), AePS (Aadhaar se), FASTag (toll, RFID).

20.4 e-Governance (Digital India)

Pahal	Jaankari
Digital India	Launch 1 July 2015; lakshya — digital infrastructure, e-services, digital literacy
Aadhaar	UIDAI; 12-digit unique number; biometric (fingerprint, iris) + demographic; Aadhaar Act 2016
DigiLocker	Documents (marksheet, DL, Aadhaar) ka digital locker — MeitY
UMANG	Ek app me kendra-rajya ki kai sarkari sevayen
BharatNet / CSC	Gram panchayaton tak optical fibre broadband / Common Service Centres (gaon me e-services)
GeM	Sarkari kharid ka online portal
CCTNS	Police thanon ko jodne wala rashtriya crime-criminal database network
MP	MPOnline (rajya ka e-services portal), CM Helpline 181, e-Uparjan (fasal kharid registration), Samagra portal (parivaar/sadasya ID se yojanaon ka laabh)

⚠️ Exam Traps:

UPI = NPCI (RBI nahi banata; RBI regulator), launch 2016. Digital India = 2015.
Gmail/Google Docs = SaaS; virtual server = IaaS.
AI term = McCarthy; IoT term = Kevin Ashton.

✍️ Practice MCQs (self-made — PYQ nahi)

P1. UPI kis sanstha ne viksit kiya? Practice MCQ

(A) RBI

(B) SBI

(C) NPCI

(D) SEBI

उत्तर: (C) NPCI

P2. Google Docs cloud computing ke kis model ka udaharan hai? Practice MCQ

(A) IaaS

(B) PaaS

(C) SaaS

(D) DaaS

उत्तर: (C) SaaS

P3. "Artificial Intelligence" shabd kisne diya? Practice MCQ

(A) Alan Turing

(B) John McCarthy

(C) Charles Babbage

(D) Bill Gates

उत्तर: (B) John McCarthy (1956)

P4. Aadhaar number kitne ank (digit) ka hota hai? Practice MCQ

(A) 10

(B) 12

(C) 14

(D) 16

उत्तर: (B) 12

📝 Last-week revision plan (Computer): (1) Har topic ka Exam Traps box, (2) Windows/Word/Excel/PPT shortcut tables, (3) Protocols + ports table, (4) Backup types table, (5) Malware + antivirus methods, (6) Number conversion ke 5 sawal khud hal karein, (7) saare 113 PYQs ek baar dobara.

💻 बुनियादी कंप्यूटर ज्ञान (Basic Computer Knowledge)

📌 1. कंप्यूटर की मूल बातें (Computer Basics) (6 min read)

1.1 Computer kya hai?

1.2 Computer ke components

1.3 Computer ki visheshtayen (Characteristics)

1.4 Computer ke prakar (Types)

📌 2. इतिहास, जनक एवं पीढ़ियाँ (History, Fathers & Generations) (7 min read)

2.1 Timeline — ganana yantra se computer tak

2.2 Computer ki peedhiyan (Generations)

2.3 "Father of ..." (जनक) — sabse zyada poochhe jaane wale

2.4 India me computer

📌 3. CPU, Motherboard एवं Ports (Hardware) (6 min read)

3.1 CPU (Central Processing Unit) — "Computer ka dimaag (Brain)"

3.2 Motherboard aur cabinet ke parts

3.3 Ports aur Connectors (2025 paper me poochhe gaye)

📌 4. मेमोरी एवं स्टोरेज (Memory & Storage) (8 min read)

4.1 Memory ki hierarchy (tez → dheema)

4.2 Primary vs Secondary memory

4.3 RAM aur ROM

4.4 Cache aur Virtual memory

4.5 Secondary storage devices

4.6 Memory ki ikaiyan (Units)

📌 5. इनपुट / आउटपुट डिवाइस (Input / Output Devices) (6 min read)

5.1 Input devices (computer ko data dene wale)

5.2 Output devices

5.3 Printers

📌 6. सॉफ्टवेयर एवं प्रोग्रामिंग भाषाएँ (Software & Languages) (7 min read)

6.1 System software vs Application software

6.2 OS / System software ki visheshtayen aur kamiyan

6.3 Licence ke hisaab se software

6.4 Programming languages aur translators

📌 7. ऑपरेटिंग सिस्टम एवं Windows (Operating System & Windows) (10 min read)

7.1 Operating System (OS) kya hai?

7.2 Windows ke hisse (Desktop & Taskbar)

7.3 Control Panel

7.4 Files aur Folders

7.5 Windows keyboard shortcuts (bahut zaroori)

📌 8. MS Word (वर्ड प्रोसेसर) (8 min read)

8.1 Basics

8.2 Ribbon tabs — kaunsa feature kahan

8.3 Zaroori features samjhein

8.4 Word shortcuts

📌 9. MS Excel (स्प्रेडशीट) (10 min read)

9.1 Basics

9.2 Formula aur cell references

9.3 Zaroori functions

9.4 Features

9.5 Excel shortcuts

📌 10. MS PowerPoint एवं File Extensions (6 min read)

10.1 PowerPoint basics

10.2 PowerPoint shortcuts

10.3 Important file extensions

📌 11. इंटरनेट, WWW, ब्राउज़र, URL, IP एवं DNS (12 min read — sabse zyada PYQ)

11.1 Internet aur WWW

11.2 Web Browser

11.3 Search Engine

11.4 URL (Uniform Resource Locator) — web address

11.5 IP address, DNS, MAC

11.6 Cookies

11.7 Social media

📌 12. ईमेल (Email) (5 min read)

Email protocols

📌 13. नेटवर्किंग (Computer Networking) (9 min read)

13.1 Network ke prakar (area ke hisaab se)

13.2 Topology (network ka dhancha)

13.3 Network devices

13.4 Transmission media aur modes

13.5 OSI Model (7 layers) aur TCP/IP

📌 14. प्रोटोकॉल एवं पोर्ट (Protocols & Ports) (5 min read)

📌 15. साइबर सुरक्षा (Cyber Security) — Malware, Attacks, Antivirus (10 min read)

15.1 Malware (Malicious Software) ke prakar

15.2 Cyber attacks aur thagi (fraud)

15.3 Hackers ke prakar

15.4 Bachav (Security measures)

📌 16. बैकअप एवं क्लाउड स्टोरेज (Backup & Cloud Storage) (6 min read — 2025 me 8 PYQ!)

16.1 Backup ke prakar

16.2 Cloud storage ke prakar

📌 17. साइबर अपराध एवं IT Act 2000 (Cyber Crime & Law) (6 min read)

17.1 Information Technology Act, 2000

17.2 Sansthayen aur helpline