Computer GK: Quick Revision for 3-5 Sure Marks

Computer GK is the easiest scoring section in any government exam — and the most neglected. Students spend weeks on History and Science but skip Computer, thinking it's "too technical." It's not. The questions are factual, not technical. If you spend just 2 hours reading this article and practicing related questions on the app, 3-5 marks are guaranteed. Let's go quick-fire.

Computer Generations & Key People

1st Generation (1940-1956): Vacuum Tubes. Example: ENIAC, UNIVAC. Huge, hot, expensive. 2nd Generation (1956-1963): Transistors. Smaller, faster. Example: IBM 1620. 3rd Generation (1963-1971): Integrated Circuits (ICs). Example: IBM 360. 4th Generation (1971-Present): Microprocessors. Example: Intel 4004 (first microprocessor). Personal computers born here. 5th Generation (Present & Beyond): Artificial Intelligence. Parallel processing, natural language understanding. Father of Computer: Charles Babbage (invented Analytical Engine). Father of Modern Computer: Alan Turing. WWW Inventor: Tim Berners-Lee (1989). First Programmer: Ada Lovelace. These names repeat in every exam.

Memory Types & Storage

RAM (Random Access Memory): Temporary memory — data lost when power off. Volatile. Two types: SRAM (fast, expensive, used in cache) and DRAM (slower, cheaper, main RAM). ROM (Read Only Memory): Permanent memory — data stays even without power. Non-volatile. Types: PROM, EPROM, EEPROM. Cache Memory: Super-fast memory between CPU and RAM. Stores frequently used data. Flash Memory: Used in pen drives, SSDs, memory cards. Non-volatile. Hard Disk: Permanent storage. Measured in GB/TB. 1 TB = 1024 GB. Memory hierarchy (fastest to slowest): Registers > Cache > RAM > Hard Disk. Bit is smallest unit. 8 Bits = 1 Byte. 1024 Bytes = 1 KB. 1024 KB = 1 MB. 1024 MB = 1 GB.

Shortcuts, File Extensions & MS Office

Keyboard Shortcuts (most asked): Ctrl+C (Copy), Ctrl+V (Paste), Ctrl+X (Cut), Ctrl+Z (Undo), Ctrl+Y (Redo), Ctrl+S (Save), Ctrl+P (Print), Ctrl+A (Select All), Ctrl+F (Find), Ctrl+N (New), Ctrl+O (Open), Alt+F4 (Close window), F1 (Help), F2 (Rename), F5 (Refresh/Slideshow in PPT), F11 (Full screen). MS Excel Formulas: =SUM(), =AVERAGE(), =COUNT(), =MAX(), =MIN(), =IF(), =VLOOKUP(). Default file extension of Excel: .xlsx. Workbook contains Worksheets. Cell = intersection of Row and Column. Columns: A, B, C... Rows: 1, 2, 3...

Common File Extensions: .pdf (Portable Document Format), .doc/.docx (MS Word), .xls/.xlsx (MS Excel), .ppt/.pptx (MS PowerPoint), .txt (Text file), .html (Webpage), .mp3 (Audio), .mp4 (Video), .jpg/.png (Image), .zip/.rar (Compressed), .exe (Executable program), .csv (Comma Separated Values). Input Devices: Keyboard, Mouse, Scanner, Microphone, Joystick, Webcam, Light Pen, Barcode Reader, OMR, OCR. Output Devices: Monitor, Printer, Speaker, Projector, Plotter. Both Input & Output: Touchscreen, Modem.

Internet, Networking & OSI Model

Internet Terms: HTML (HyperText Markup Language — builds web pages). URL (Uniform Resource Locator — web address). DNS (Domain Name System — converts website names to IP addresses). ISP (Internet Service Provider — Jio, Airtel). HTTP (HyperText Transfer Protocol). HTTPS (HTTP + Secure, uses SSL). FTP (File Transfer Protocol — for file transfers). IP Address: Unique address of every device on internet. IPv4: 32-bit. IPv6: 128-bit. WWW invented by Tim Berners-Lee in 1989.

OSI Model has 7 layers. Mnemonic: "Please Do Not Throw Sausage Pizza Away" — Physical, Data Link, Network, Transport, Session, Presentation, Application. This mnemonic is a lifesaver — one question on OSI layers comes in almost every SSC and RRB exam. Programming Languages: C, C++, Java, Python, BASIC, COBOL, FORTRAN. Machine Language = Binary (0s and 1s). Assembly Language uses mnemonics. High-level languages are human-readable. DBMS (Database Management System): Organizes data in tables. SQL is the language used. Examples: MySQL, Oracle, MS Access.

Binary Basics & Final Tips

Binary to Decimal: Binary uses only 0 and 1. Each position = power of 2. Example: 1010 in binary = (1x8)+(0x4)+(1x2)+(0x1) = 10 in decimal. Decimal to Binary: Keep dividing by 2, write remainders from bottom to top. Example: 13 = 1101 in binary. Octal (base 8) and Hexadecimal (base 16) are also asked sometimes. Hexadecimal uses 0-9 and A-F (A=10, B=11... F=15).

Computer GK is pure memorization — no analysis needed. Use the app to practice Computer MCQs, and you'll notice the same 40-50 facts getting asked in different ways. Master those 50 facts, and 3-5 marks are permanently secured in every exam you appear for. Those easy marks can be the difference between selection and waiting list. Go grab them!