Computer Fundamentals

Comprehensive notes + 50 practice MCQs. Correct answers are highlighted.

📘 Quick Notes

What is a Computer?

A computer is an electronic device that accepts data (input), processes it, and produces information (output). It comprises hardware and software.

Hardware vs Software

Hardware: Physical components (CPU, RAM, hard disk, motherboard, peripherals).
Software: Programs and operating systems that run on hardware (Windows, Linux, applications).

Basic Components

CPU (Central Processing Unit): Executes instructions. Clock speed measured in GHz.
Memory: RAM (volatile), ROM (non-volatile), Cache (fast small memory).
Storage: HDD (mechanical), SSD (flash-based), external storage.
Motherboard & Buses: Connects components; buses carry data/address/control lines.
Peripherals: Input (keyboard, mouse), Output (monitor, printer).

Software Categories

System Software: OS, device drivers, utilities.
Application Software: Word processors, browsers, games.
Development Software: IDEs, compilers, debuggers.

Operating System (OS)

Manages hardware resources, provides user interface, file management, process scheduling, memory management, and device control. Examples: Windows, macOS, Linux, Android, iOS.

Data Representation

Computers use binary (0 and 1). Common units: bit, byte (8 bits), KB (1024 bytes), MB, GB, TB. Character encoding: ASCII, Unicode.

Networks & Internet

Network Types: LAN, WAN, MAN.
Protocols: TCP/IP, HTTP, FTP, SMTP, DNS.
IP Addressing: IPv4 (dotted decimal), IPv6 (hex).

Database Basics

Database stores structured data. RDBMS uses tables and SQL to query (SELECT, INSERT, UPDATE, DELETE).

Security

Measures include antivirus, firewall, encryption, backups, secure passwords, multi-factor authentication.

Other Key Concepts

Virtualization & Cloud: Virtual machines, SaaS, PaaS, IaaS.
Backup & Recovery: Full, incremental, differential backups.
File Systems: FAT32, NTFS, ext4.
Programming Basics: Source code, compiler vs interpreter.

📝 50 Practice Questions (Answers highlighted)

1. What does CPU stand for?

A) Central Process Unit
B) Central Processing Unit ✅
C) Computer Processing Unit
D) Central Program Unit

2. Which memory is volatile?

A) ROM
B) RAM ✅
C) SSD
D) HDD

3. Which storage is fastest?

A) HDD
B) SSD ✅
C) CD-ROM
D) Tape

4. Which is an example of system software?

A) Microsoft Word
B) Operating System ✅
C) Photoshop
D) VLC Media Player

5. Which device is an input device?

A) Keyboard ✅
B) Monitor
C) Speaker
D) Printer

6. Which is an output device?

A) Microphone
B) Scanner
C) Monitor ✅
D) Keyboard

7. How many bits are there in a byte?

A) 4
B) 8 ✅
C) 16
D) 2

8. ASCII is used to encode what?

A) Characters ✅
B) Images
C) Sound
D) Video

9. Which bus carries memory addresses?

A) Address Bus ✅
B) Data Bus
C) Control Bus
D) Power Bus

10. The main circuit board of a computer is called?

A) Motherboard ✅
B) Backplane
C) Daughterboard
D) Control board

11. Cache memory is used to:

A) Speed up access to frequently used data ✅
B) Store long term files
C) Replace RAM
D) Backup data

12. ROM stands for:

A) Read Only Memory
B) Read Only Memory ✅
C) Random Only Memory
D) Rapid Output Memory

13. Which OS is open-source?

A) Windows
B) Linux ✅
C) macOS
D) iOS

14. A graphical user interface is abbreviated as:

A) GUI ✅
B) CLI
C) API
D) SDK

15. IPv4 addresses are written in:

A) Hexadecimal
B) Dotted decimal ✅
C) Binary only
D) Base64

16. DNS stands for:

A) Domain Name System
B) Domain Name System ✅
C) Data Name Service
D) Direct Name Service

17. HTTP is used for:

A) Web communication ✅
B) Email transfer
C) File transfer only
D) Database queries

18. A multi-core CPU means:

A) Multiple processing units on one chip ✅
B) Multiple CPUs in same system
C) Multiple motherboards
D) Multiple RAM modules

19. Binary for decimal 5 is:

A) 1010
B) 0101 or 101 ✅
C) 111
D) 1001

20. FTP protocol is mainly used for:

A) File transfer ✅
B) Email delivery
C) Web browsing
D) Remote login

21. SQL stands for:

A) Structured Query Language
B) Structured Query Language ✅
C) Simple Query Language
D) Sequential Query Language

22. Which converts entire source code into machine code before execution?

A) Interpreter
B) Compiler ✅
C) Assembler
D) Linker

23. Virtual machine allows:

A) Running multiple OS instances on one physical machine ✅
B) Faster CPU clocks
C) More physical memory
D) Hardware replacement

24. SaaS stands for:

A) Software as a Service ✅
B) Storage as a Service
C) System as a Service
D) Security as a Service

25. Incremental backup saves:

A) All files every time
B) Only changed files since last backup ✅
C) Only system files
D) Only archived files

26. A firewall is used to:

A) Filter network traffic ✅
B) Encrypt files
C) Backup data
D) Update OS

27. Which software protects against malware?

A) Antivirus ✅
B) Disk defragmenter
C) Registry cleaner
D) File compressor

28. HDMI port is used for:

A) Audio only
B) Data transfer
C) Audio & Video ✅
D) Power only

29. RAID 1 provides:

A) Striping for speed
B) Mirroring for redundancy ✅
C) Parity only
D) Single drive

30. BIOS is responsible for:

A) Starting the computer and POST ✅
B) File storage
C) Running applications
D) Network routing

31. USB stands for:

A) Universal Serial Bus ✅
B) Universal System Bus
C) Unified Serial Bus
D) User Serial Bus

32. DPI is a measure related to:

A) Sound quality
B) Mouse or printer resolution ✅
C) CPU speed
D) Network latency

33. The kernel is part of which software?

A) Operating System ✅
B) Application
C) Firmware
D) Driver

34. A running program is called a:

A) Process ✅
B) Thread
C) Service
D) Job

35. Multitasking in OS means:

A) Running multiple tasks simultaneously ✅
B) Running one task at a time
C) Using multiple CPUs only
D) None of these

36. Web cookies are used to:

A) Store small pieces of data on user's browser ✅
B) Encrypt web pages
C) Speed up downloads
D) Replace cache

37. SSL is used to:

A) Secure web communication ✅
B) Compress data
C) Authenticate emails
D) Backup data

38. Ethernet is primarily used for:

A) LAN connectivity ✅
B) Wide area networking
C) Wireless communication
D) Satellite links

39. A router works at which OSI layer?

A) Network layer ✅
B) Data link layer
C) Transport layer
D) Application layer

40. Ransomware is a type of:

A) Malware that encrypts files and demands payment ✅
B) Hardware damage tool
C) Network optimizer
D) Disk cleaner

41. HTML is used to:

A) Structure web pages ✅
B) Style web pages only
C) Program server logic
D) Store databases

42. CSS mainly controls:

A) Presentation and layout of web pages ✅
B) Database queries
C) Server-side scripting
D) Network settings

43. HTTPS ensures:

A) Encrypted web traffic ✅
B) Faster downloads
C) Anonymous browsing
D) Unlimited bandwidth

44. Patching an OS mainly fixes:

A) Security vulnerabilities ✅
B) Hardware defects
C) Power supply issues
D) Network outages

45. A file with extension .docx is usually created by:

A) Microsoft Word ✅
B) Notepad
C) Excel
D) PowerPoint

46. A graphics card is also known as:

A) GPU ✅
B) CPU
C) NIC
D) PSU

47. Lossless compression means:

A) Original data can be perfectly restored ✅
B) Some quality is lost
C) Data is encrypted
D) Files are corrupted

48. An AND gate outputs 1 when:

A) Any input is 1
B) Both inputs are 1 ✅
C) Both inputs are 0
D) None are 1

49. Unicode was developed to:

A) Represent characters from all languages ✅
B) Replace binary
C) Speed up processing
D) Encrypt text

50. Which of these is a relational database?

A) MySQL ✅
B) MongoDB
C) Redis
D) Cassandra