Complete Summary and Solutions for Computer System – NCERT Class XI Informatics Practices, Chapter 1

Full Chapter Summary & Detailed Notes - Computer System Class 11 NCERT

Overview & Key Concepts

Chapter Goal: Understand computer system components, evolution, memory types/units, data handling, and software categories. Exam Focus: Block diagram, timeline inventions, memory conversions, software types; 2025 Updates: AI in IoT, cloud storage trends. Fun Fact: Turing's quote on AI intelligence. Core Idea: Computer as input-process-output system; interlinks to programming chapters. Real-World: SSD vs HDD in modern devices.
Wider Scope: From hardware to software; sources: Figures (1.1 block, 1.5 timeline, 1.7 storage), tables (1.1 units), activities (data tools, recovery).
Expanded Content: Include modern aspects like cloud computing, cybersecurity in data recovery; point-wise for recall; add 2025 relevance like quantum memory.

Introduction to Computer System

Definition: Electronic device for input-processing-output; system includes hardware (CPU, memory, I/O, storage) + software.
Forms: Servers to smartphones; block diagram (Fig 1.1): Data flow via CPU (ALU+CU), primary/secondary memory, I/O.
CPU: Brain; fetches/executes via registers, ALU (arith/logic), CU (control flow); microprocessor.
Input Devices: Keyboard, mouse, scanner, touch, voice, braille (Fig 1.2); data to RAM then secondary.
Output Devices: Monitor, printer (inkjet/laser/dot/3D), speaker, braille display (Fig 1.3); digital to human-readable; 3D for prototypes/organs.
Example: Voice Input: Google search; data temp in RAM, perm in secondary.
Expanded: Evidence: Von Neumann (Fig 1.4); debates: Hardware limits in AI; real: Post-2020 remote I/O boom.

Conceptual Diagram: Computer Block (Fig 1.1)

Central CPU box with ALU/CU; arrows from Input to Primary Memory to Output; Secondary Storage loop. Visualizes data flow; ties to evolution.

Why This Guide Stands Out

Comprehensive: All subtopics point-wise, figure integrations; 2025 with IoT ethics (e.g., data privacy), memory analyzed for big data.

Evolution of Computer

Timeline (Fig 1.5): Abacus (500 BC, arithmetic) → Pascaline (1642, add/sub) → Analytical Engine (1834, Babbage, mechanical basis) → Tabulating Machine (1890, Hollerith, punched cards) → Turing Machine (1937, programmable) → Transistor (1947, replace vacuum) → EDVAC/ENIAC (1945, Von Neumann stored-program) → IC (1970s, miniaturize).
Key Milestones: Von Neumann architecture (Fig 1.4); LSI (1970s, full CPU chip), VLSI (1980s, 3M components), SLSI (10^6); Moore's Law (Fig 1.6, transistors double/2yrs, costs halve).
Modern: IBM PC (1981), Macintosh (1984, GUI), WWW (1990s), Laptops/Smartphones/ Tablets, Wearables (smartwatch), IoT/AI appliances.
Expanded: Evidence: Punched cards; debates: Mechanical vs electronic; real: Quantum computing 2025.

Computer Memory

Units (Table 1.1): Bit (0/1) → Nibble (4 bits) → Byte (8 bits) → KB (1024 B) → MB (1024 KB) → GB → TB → PB → EB → ZB → YB.
Types: Primary (essential, CPU direct: RAM volatile/temp/fast, ROM non-volatile/boot/perm; Cache high-speed CPU-RAM bridge for frequent data); Secondary (auxiliary/non-volatile/large/slow/indirect: HDD magnetic, SSD flash/fast, CD/DVD optical, Pen Drive portable, Tape backup; Fig 1.7).
Data Handling: Capture (keyboard/barcode/voice/sensors; Fig 1.8, heterogeneity challenge; Act 1.2); Storage (files/DB/servers, upgrade periodic, data servers for orgs); Retrieval (fast search, minimize time); Deletion (mark free/not erase, threats: crash/hacker); Recovery (if not overwritten, tools; Act 1.3/1.4); Security (passwords/encryption/shred before dispose, confidentiality).
Key Insight: Primary for processing, secondary for permanence; challenges: Volume, access time, volatility.
Think & Reflect: Components communicate via buses/signals; RAM no secondary? No install (perm storage need).
Expanded: Evidence: SSD speed; debates: Volatile vs non; real: Cloud backups 2025.

Software

Need: Interface hardware-user; hardware useless alone; softcopy (digital) vs hardcopy (printed).
Categories (Fig 1.9): System (basic: OS manages apps/security e.g. Windows/Linux/Ubuntu; Utilities maintenance e.g. defrag/antivirus; Drivers mediate device-OS); Programming Tools (compilers/assemblers/text editors); Application (General ready-made e.g. Calc/Photoshop/Firefox; Custom tailored e.g. school mgmt/accounting).
Types: FOSS (free/open source e.g. Ubuntu/Python/LibreOffice, collaborative); Freeware (free/no source e.g. Skype/Adobe Reader); Proprietary (paid/copyright e.g. Windows/Tally/Quickheal).
Expanded: Evidence: Drivers hide hardware details; real: Open-source in AI 2025; Act 1.5: Locate drivers; Act 1.6: Install app.

Exam Activities

List storage devices (Act 1.1); data capture tools (Act 1.2); recover deleted (Act 1.4); install app (Act 1.6).

Summary Key Points

Computer: Input-process-output; hardware (CPU/memory/I/O) + software.
Evolution: Abacus to IoT; Moore's Law.
Memory: Units (bit-YB); Primary (RAM/ROM/Cache), Secondary (HDD/SSD).
Data: Capture/storage/retrieval/deletion/recovery/security.
Software: System (OS/utilities/drivers), App (general/custom), FOSS/Freeware/Proprietary.

Project & Group Ideas

Group timeline poster; individual memory calc.
Debate: FOSS vs Proprietary.
Ethical role-play: Data recovery privacy.

Key Definitions & Terms - Complete Glossary

All terms from chapter; detailed with examples, relevance. Expanded: 30+ terms grouped by subtopic; added advanced like "cloud storage", "quantum bits" for depth/easy flashcards.

Computer System

Hardware + software for input-process-output. Ex: Desktop with OS. Relevance: Basic unit.

CPU

Brain: ALU (arith/logic), CU (control), registers. Ex: Microprocessor chip. Relevance: Processing core.

Input Device

Control signals to digital. Ex: Keyboard/mouse. Relevance: Data entry.

Output Device

Digital to human-readable. Ex: Monitor/printer. Relevance: Result display.

Primary Memory

RAM (volatile) / ROM (non-volatile). Ex: Boot loader in ROM. Relevance: Fast access.

Secondary Memory

Non-volatile/large storage. Ex: HDD/SSD. Relevance: Permanent save.

Cache Memory

High-speed between CPU/RAM. Ex: Frequent data copies. Relevance: Speed up.

Bit/Byte

Basic: 0/1 bit; 8 bits byte. Ex: 1010 nibble. Relevance: Data units.

Von Neumann

Stored-program architecture. Ex: ENIAC. Relevance: Modern basis.

Moore's Law

Transistors double every 2 years. Ex: IC growth (Fig 1.6). Relevance: Tech advance.

Data Capture

Gather digital from sources. Ex: Barcode reader. Relevance: Input start.

Data Recovery

Retrieve deleted/corrupted. Ex: Unoverwrite space. Relevance: Security.

Software

Instructions for hardware. Ex: OS/apps. Relevance: Functionality.

System Software

OS/utilities/drivers. Ex: Windows. Relevance: Core operation.

Application Software

General/custom. Ex: Calc/school mgmt. Relevance: User tasks.

FOSS

Free/Open Source. Ex: Ubuntu. Relevance: Collaborative.

Proprietary

Copyrighted/paid. Ex: Tally. Relevance: Commercial.

IoT

Internet of Things. Ex: Smartwatch. Relevance: Modern evolution.

Cloud Storage

Advanced secondary. Ex: Google Drive. Relevance: 2025 big data.

Quantum Bits

Advanced (qubits). Ex: Future memory. Relevance: Next-gen.

Softcopy

Digital file. Ex: PDF. Relevance: Vs hardcopy.

Hardcopy

Printed output. Ex: Document print. Relevance: Physical form.

Device Driver

Hardware-OS mediator. Ex: Printer driver. Relevance: Device control.

Operating System

Manages hardware/software. Ex: Ubuntu. Relevance: Basic interface.

Freeware

Free use/no source. Ex: Skype. Relevance: Accessible.

Nibble

4 bits. Ex: 1010. Relevance: Grouping unit.

Volatile Memory

Loses data on power off. Ex: RAM. Relevance: Temp storage.

Non-Volatile Memory

Retains data. Ex: ROM/SSD. Relevance: Perm storage.

Data Shredding

Secure deletion. Ex: Before dispose. Relevance: Confidentiality.

Encryption

Data protection. Ex: File passwords. Relevance: Security.

SSD

Solid-State Drive. Ex: Fast storage. Relevance: Modern secondary.

HDD

Hard Disk Drive. Ex: Magnetic storage. Relevance: Traditional.

Braille Keyboard

Accessibility input. Ex: Visually impaired. Relevance: Inclusive.

3D Printer

Physical replica output. Ex: Prototypes. Relevance: Advanced.

Punched Card

Early data storage. Ex: Tabulating machine. Relevance: Historical.

Tip: Group by hardware/software; examples for recall. Depth: Debates (e.g., SSD vs HDD). Errors: Confuse RAM/ROM. Historical: Turing Machine. Interlinks: To Ch2 programming. Advanced: Encryption. Real-Life: Smartphone system. Graphs: Timeline. Coherent: Evidence → Interpretation. For easy learning: Flashcard per term with example.

Text Book Questions & Answers - NCERT Exercises

Direct from chapter exercises (pages 13-14). Answers based on chapter content, point-wise for exams.

Short Answer Questions

1. Name the software required to make a computer functional. Write down its two primary functions.

Answer:

Operating System (e.g., Windows, Ubuntu).
Primary Functions: (i) Manages hardware and software resources; (ii) Provides user interface and security.

2. What is the need of RAM? How does it differ from ROM?

Answer:

Need: Temporary storage for data/instructions during processing; fast CPU access.
Difference: RAM volatile (loses data on power off), ROM non-volatile (retains boot data).

3. What is the need for secondary memory?

Answer:

Large/non-volatile permanent storage for data/instructions; supplements limited primary memory.

6. Mention any browsers used for browsing the internet.

Answer:

Mozilla Firefox, Google Chrome, Microsoft Edge.

Medium Answer Questions

4. Draw the block diagram of a computer system. Briefly write about the functionality of each component.

Answer:

Block Diagram: (Describe Fig 1.1) Input → CPU (ALU/CU) ↔ Primary Memory ↔ Output; Secondary Storage loop.
Components: Input: Enters data; CPU: Processes (ALU arith/logic, CU control); Primary Memory: Temp store (RAM/ROM); Output: Displays results; Secondary: Permanent large store.

5. Differentiate between proprietary software and freeware software. Name two software of each type.

Answer:

Proprietary: Paid, copyrighted, no source (e.g., Microsoft Windows, Tally).
Freeware: Free use, no source/modify (e.g., Skype, Adobe Reader).

Long Answer Questions

7. Name the input/output device used to do the following: a) To output audio b) To enter textual data c) To make hard copy of a text file d) To display the data/information e) To enter audio-based command f) To build 3D models g) To assist a visually impaired individual in entering data

Answer:

a) Speaker/Headphone
b) Keyboard
c) Printer
d) Monitor
e) Microphone (voice input)
f) 3D Printer
g) Braille Keyboard/Display

8. Identify the category (system, application, programming tool) of the following software: a) Compiler b) Assembler c) Ubuntu d) Text editor

Answer:

a) Programming tool
b) Programming tool
c) System (OS)
d) Programming tool

9. Convert the following into bytes: a) 2 MB b) 3.7 GB c) 1.2 TB

Answer:

a) 2 MB = 2 × 1024 × 1024 = 2,097,152 Bytes
b) 3.7 GB = 3.7 × 1024 × 1024 × 1024 ≈ 3,980,691,840 Bytes
c) 1.2 TB = 1.2 × 1024 × 1024 × 1024 × 1024 ≈ 1,326,492,800,000 Bytes

10. What is the security threats involved when we throw away electronic gadgets that are non-functional?

Answer:

Data recovery by unauthorized (deleted not erased, just marked free); confidentiality breach if sensitive info retrieved.
Mitigate: Shred/overwrite before dispose.

11. Write down the type of memory needed to do the following: a) To store data permanently b) To execute the program c) To store the instructions which can not be overwritten.

Answer:

a) Secondary Memory (e.g., HDD/SSD)
b) RAM (Primary, volatile for processing)
c) ROM (Non-volatile, read-only)

Tip: Practice diagrams (Q4); conversions (Q9). Full marks: Point-wise, examples from chapter.

Key Concepts - In-Depth Exploration

Core ideas with examples, pitfalls, interlinks. Expanded: All concepts with steps/examples/pitfalls for easy learning. Depth: Debates, analysis.

Computer System Process

Steps: 1. Input data, 2. Process (CPU), 3. Output result. Ex: Typing to print. Pitfall: No software. Interlink: Memory. Depth: I-P-O cycle.

CPU Operations

Steps: 1. Fetch instr, 2. Decode, 3. Execute (ALU). Ex: Add numbers. Pitfall: Overheat. Interlink: Registers. Depth: Von Neumann.

Memory Hierarchy

Steps: 1. Cache fast, 2. RAM temp, 3. Secondary perm. Ex: App load. Pitfall: Full RAM crash. Interlink: Storage. Depth: Speed-cost trade.

Data Units

Steps: 1. Bit binary, 2. Group to byte/KB. Ex: 1 MB file. Pitfall: Decimal confuse. Interlink: Big data. Depth: Binary math.

Evolution Milestones

Steps: 1. Mechanical, 2. Electronic, 3. Integrated. Ex: Transistor shift. Pitfall: Ignore history. Interlink: Moore's. Depth: Innovation waves.

Software Interface

Steps: 1. System base, 2. App user, 3. Drivers device. Ex: OS run app. Pitfall: Incompat. Interlink: Hardware. Depth: Layers.

Data Capture

Steps: 1. Source gather, 2. Digital convert. Ex: Scanner. Pitfall: Error input. Interlink: Retrieval. Depth: Hetero challenges.

Recovery Process

Steps: 1. Check overwrite, 2. Tool retrieve. Ex: Deleted file. Pitfall: Late action. Interlink: Security. Depth: Forensics.

FOSS Benefits

Steps: 1. Free access, 2. Modify/improve. Ex: Linux. Pitfall: Learning curve. Interlink: Proprietary. Depth: Community.

IoT Integration

Steps: 1. Connect devices, 2. AI leverage. Ex: Smart home. Pitfall: Privacy. Interlink: Evolution. Depth: 2025 trend.

Cache Mechanism

Steps: 1. Store frequent, 2. Quick check. Ex: Web cache. Pitfall: Miss penalty. Interlink: RAM. Depth: Levels L1/L2.

Secondary Storage

Steps: 1. Load to RAM, 2. CPU access. Ex: HDD save. Pitfall: Slow transfer. Interlink: Backup. Depth: RAID.

Software Categories

Steps: 1. System core, 2. App specific. Ex: Driver print. Pitfall: No OS. Interlink: Functions. Depth: POSDCORB analog.

Advanced: Encryption checklists, unit feasibility. Pitfalls: Volatility. Interlinks: To Ch3 data handling. Real: Laptop assembly. Depth: 14 concepts details. Examples: Real figs. Graphs: Timeline. Errors: Unit mix. Tips: Steps evidence; compare tables (memory/software).

Historical Perspectives - Detailed Guide

Timeline of inventions/evolutions; expanded with points; links to pioneers/debates. Added Turing's machine, Babbage's engine.

Ancient (500 BC)

Abacus: Mechanical calc.
Basis arithmetic.

Depth: Manual tool.

17th C (1642)

Pascaline: Add/subtract.
Repeated ops for mul/div.

Depth: First mechanical.

19th C (1834)

Babbage Analytical: Input/process/store/output.
Modern blueprint.

Depth: Punched cards program.

Early 20th (1890-1937)

Hollerith Tabulating: Data summary.
Turing Machine: Programmable concept.

Depth: Programming step.

Mid 20th (1945-1970)

ENIAC/EDVAC: Stored-program.
Transistor/IC: Miniaturize.

Depth: Von Neumann arch.

Modern (1980s+)

PC/GUI/WWW: Mass use.
IoT/AI: Connected.

Depth: Moore's impact.

Tip: Link to pioneers like Turing. Depth: Reflexive history. Examples: 1945 ENIAC. Graphs: Fig 1.5. Advanced: Post-2025 quantum. Easy: Bullets impacts.

Solved Examples - From Text with Simple Explanations

Expanded with evidence, calcs; focus on applications, analysis. Added unit conversions, timeline apps.

Example 1: Memory Conversion

Simple Explanation: Binary units calc.

Step 1: 2 MB = 2 * 1024 KB.
Step 2: = 2048 KB = 2048 * 1024 B.
Step 3: = 2,097,152 Bytes.
Step 4: Verify table.
Step 5: Apply to file size.
Simple Way: Multiply 1024 per level.

Example 2: Data Flow in System

Simple Explanation: I-P-O cycle.

Step 1: Input via keyboard to RAM.
Step 2: CPU fetch/process (ALU add).
Step 3: Store result in register.
Step 4: Output to monitor.
Step 5: Save to HDD.
Simple Way: Enter → Think → Show → Save.

Example 3: Software Installation

Simple Explanation: App setup.

Step 1: Download (e.g., LibreOffice).
Step 2: Run installer via OS.
Step 3: Follow prompts (license).
Step 4: Integrate drivers if needed.
Step 5: Launch from desktop.
Simple Way: Get → Install → Use.

Example 4: Evolution Impact

Simple Explanation: Tech shift.

Step 1: Vacuum to transistor (1947).
Step 2: Size/power improve.
Step 3: IC (1970s) miniaturize.
Step 4: Microprocessor single chip.
Step 5: Laptops portable.
Simple Way: Big room → Pocket device.

Example 5: Data Recovery

Simple Explanation: File rescue.

Step 1: Delete (Shift+Del).
Step 2: Use tool (Recycle Bin).
Step 3: Scan unallocated space.
Step 4: Restore if intact.
Step 5: Backup future.
Simple Way: Trash → Find → Get back.

Example 6: Cache Hit

Simple Explanation: Speed access.

Step 1: CPU request data.
Step 2: Check cache first.
Step 3: Hit → Quick read.
Step 4: Miss → RAM slower.
Step 5: Update cache.
Simple Way: Quick drawer → Shelf if not.

Tip: Practice self-assess; troubleshoot (e.g., conversion errors). Added for units, processes.

Interactive Quiz - Master Computer System

10 MCQs in full sentences; 80%+ goal. Covers components, memory, software, evolution.

Quick Revision Notes & Mnemonics

Concise, easy-to-learn summaries for all subtopics. Structured in tables for quick scan: Key points, examples, mnemonics. Covers components, evolution, memory, software. Bold key terms; short phrases for fast reading.

Subtopic	Key Points	Examples	Mnemonics/Tips
Components	CPU: ALU (ops), CU (control), Registers (temp). I/O: Input (keyboard), Output (monitor). Memory: Primary (RAM/ROM), Secondary (HDD).	Block diagram (Fig 1.1); Voice search input.	ACIRS (ALU, CU, Input, Registers, Storage). Tip: "Brain (CPU) + Eyes/Ears (I/O) + Notebook (Memory)".
Evolution	Timeline: Abacus → Pascaline → Analytical → ENIAC → IC → Microprocessor. Milestones: Von Neumann, Moore's Law (double transistors). Modern: GUI, WWW, IoT.	Fig 1.5 timeline; Transistor 1947.	APATEI (Abacus, Pascal, Analytical, Turing, ENIAC, IC). Tip: "Ancient Past To Modern AI" – Scan inventions.
Memory Units	Basic: Bit (0/1), Nibble (4), Byte (8). Large: KB (1024 B) → MB → GB → TB → PB. Up to YB.	Table 1.1; 1 MB = 1024 KB.	BNK MGT PEBZY (Bit, Nibble, Kilo, Mega... Yotta). Tip: "Binary Numbers Keep Multiplying Greatly" – *1024 each.
Memory Types	Primary: RAM (volatile/fast), ROM (non-volatile/boot). Cache: CPU-RAM bridge. Secondary: HDD/SSD (large/perm).	Fig 1.7; SSD faster than HDD.	PRC (Primary RAM Cache, ROM, Secondary). Tip: Pyramid – Top fast/small (Cache), Base large/slow (Secondary).
Data Handling	Capture: Digital gather (barcode). Storage/Retrieval: Files/DB, fast access. Deletion/Recovery: Mark free, unoverwrite.	Fig 1.8; Shred old drives.	CSRD (Capture, Store, Retrieve, Delete). Tip: "Collect, Save, Search, Salvage" – Chain process.
Software	System: OS (Windows), Utilities, Drivers. Application: General (Calc), Custom. Types: FOSS (Ubuntu), Proprietary (Tally).	Fig 1.9; Install LibreOffice.	SAG FOP (System, App General, Custom; FOSS, Open, Prop). Tip: "Soft As Glue – Sticks Hardware".

Overall Tip: Use ACIRS-APATEI-PRC for full scan (5 mins). Flashcards: Front (term), Back (points + mnemonic). Print table for wall revision. Covers 100% chapter – easy for exams!

Key Terms & Processes - All Key

Expanded table 30+ rows; quick ref. Added advanced (e.g., SSD, IoT).

Term/Process	Description	Example	Usage
Computer System	Hardware+software I-P-O	Desktop	Core
CPU	Brain ALU/CU	Microprocessor	Process
ALU	Arith/logic unit	Add numbers	Ops
Input Device	Digital convert	Keyboard	Entry
Output Device	Human readable	Printer	Display
RAM	Volatile primary	App load	Temp
ROM	Non-volatile	Boot	Perm
Cache	High-speed	Frequent data	Speed
Secondary Memory	Large storage	HDD	Save
Bit	0/1 basic	Binary	Unit
Byte	8 bits	Character	Data
Von Neumann	Stored-program	ENIAC	Arch
Moore's Law	Transistors double	IC growth	Advance
Data Capture	Gather digital	Barcode	Input
Data Recovery	Retrieve deleted	Tool scan	Security
Software	Instructions set	OS	Function
OS	System manager	Windows	Interface
Application Software	User tasks	Calc	Specific
FOSS	Free source	Python	Collab
Proprietary	Paid copyright	Tally	Commercial
SSD	Solid-state drive	Fast storage	Modern
IoT	Internet Things	Smartwatch	Connect
Cloud Storage	Online secondary	Google Drive	2025
Encryption	Data protect	Passwords	Security
3D Printer	Physical replica	Prototypes	Output
Punched Card	Early storage	Tabulating	Historical
Analytical Engine	Mechanical computer	Babbage	Basis
Turing Machine	Programmable concept	AI origin	Theory
LSI/VLSI	Scale integration	Chip components	Mini
Data Retrieval	Fetch stored	DB search	Access
Device Driver	Hardware mediate	Printer	Interface
Softcopy	Digital file	PDF	Vs Hard
Big Data	High volume	Social media	Challenge
Quantum Bits	Future memory	Qubits	Advanced
Nibble	4 bits group	1010	Basic unit
Freeware	Free no source	Skype	Accessible

Tip: Examples memory; sort subtopic. Easy: Table scan. Added 10 rows depth.

Processes Step-by-Step

Step-by-step breakdowns of core processes. Visual descriptions for easy understanding; no diagrams, focus on actionable steps with examples.

Process 1: CPU Execution Cycle

Step 1: Fetch instruction from RAM.
Step 2: Decode via CU.
Step 3: Execute arith/logic in ALU.
Step 4: Store result in register.
Step 5: Repeat for next.

Visual: Loop arrow – Fetch → Decode → Execute → Store.

Process 2: Memory Unit Conversion

Step 1: Identify unit (e.g., 3 GB).
Step 2: Multiply by 1024 to MB.
Step 3: = 3072 MB, then to KB/Bytes.
Step 4: Use table verify.
Step 5: Apply to storage need.

Visual: Ladder climb – Each rung *1024.

Process 3: Data Capture to Storage

Step 1: Gather via input (barcode).
Step 2: Convert digital to RAM.
Step 3: Process/save to file/DB.
Step 4: Transfer to secondary (HDD).
Step 5: Backup for future.

Visual: Pipeline – Source → RAM → File → Drive.

Process 4: Software Installation

Step 1: Download from source.
Step 2: Run via OS.
Step 3: Accept terms/drivers.
Step 4: Configure paths.
Step 5: Test launch.

Visual: Box unpack – Download → Install → Run.

Process 5: Data Recovery

Step 1: Identify deletion type.
Step 2: Use tool scan space.
Step 3: Locate fragments.
Step 4: Restore to new location.
Step 5: Verify integrity.

Visual: Detective search – Deleted → Scan → Recover.

Process 6: Cache Access

Step 1: CPU data request.
Step 2: Check cache levels.
Step 3: Hit → Direct use.
Step 4: Miss → Fetch RAM, update cache.
Step 5: Optimize frequent.

Visual: Nested boxes – Cache inner, RAM outer.

Tip: Follow steps like recipe; apply to figs (1.1/1.7). Easy: Number + example per step.

Complete Summary and Solutions for Computer System – NCERT Class XI Informatics Practices, Chapter 1 – Explanation, Questions, Answers

Computer System

Full Chapter Summary & Detailed Notes - Computer System Class 11 NCERT

Overview & Key Concepts

Introduction to Computer System

Conceptual Diagram: Computer Block (Fig 1.1)

Why This Guide Stands Out

Evolution of Computer

Computer Memory

Software

Exam Activities

Summary Key Points

Project & Group Ideas

Key Definitions & Terms - Complete Glossary

Computer System

CPU

Input Device

Output Device

Primary Memory

Secondary Memory

Cache Memory

Bit/Byte

Von Neumann

Moore's Law

Data Capture

Data Recovery

Software

System Software

Application Software

FOSS

Proprietary

IoT

Cloud Storage

Quantum Bits

Softcopy

Hardcopy

Device Driver

Operating System

Freeware

Nibble

Volatile Memory

Non-Volatile Memory

Data Shredding

Encryption

SSD

HDD

Braille Keyboard

3D Printer

Punched Card

Text Book Questions & Answers - NCERT Exercises

Short Answer Questions

1. Name the software required to make a computer functional. Write down its two primary functions.

2. What is the need of RAM? How does it differ from ROM?

3. What is the need for secondary memory?

6. Mention any browsers used for browsing the internet.

Medium Answer Questions

4. Draw the block diagram of a computer system. Briefly write about the functionality of each component.

5. Differentiate between proprietary software and freeware software. Name two software of each type.

Long Answer Questions

7. Name the input/output device used to do the following: a) To output audio b) To enter textual data c) To make hard copy of a text file d) To display the data/information e) To enter audio-based command f) To build 3D models g) To assist a visually impaired individual in entering data

8. Identify the category (system, application, programming tool) of the following software: a) Compiler b) Assembler c) Ubuntu d) Text editor

9. Convert the following into bytes: a) 2 MB b) 3.7 GB c) 1.2 TB

10. What is the security threats involved when we throw away electronic gadgets that are non-functional?

11. Write down the type of memory needed to do the following: a) To store data permanently b) To execute the program c) To store the instructions which can not be overwritten.

Key Concepts - In-Depth Exploration

Computer System Process

CPU Operations

Memory Hierarchy

Data Units

Evolution Milestones

Software Interface

Data Capture

Recovery Process

FOSS Benefits

IoT Integration

Cache Mechanism

Secondary Storage

Software Categories

Historical Perspectives - Detailed Guide

Ancient (500 BC)