Basic Computer Knowledge
What is tested
Objective questions on hardware, software, memory, operating systems, word processing, spreadsheets, internet basics, e-governance and computer security. Depth is elementary, but precise definitions and shortcut keys are asked.
Core facts
- Hardware vs software: CPU, RAM, hard disk, keyboard are hardware; operating systems and applications are software. The CPU has ALU, control unit and registers.
- Memory ladder: 1 byte = 8 bits; 1 KB = 1024 bytes; 1 MB = 1024 KB; 1 GB = 1024 MB; 1 TB = 1024 GB. RAM is volatile, ROM is non-volatile.
- Shortcuts: Ctrl+C copy, Ctrl+X cut, Ctrl+V paste, Ctrl+Z undo, Ctrl+Y redo, Ctrl+S save, Ctrl+P print, Ctrl+A select all, Ctrl+F find, Alt+F4 close window, F5 refresh (and start slide show in PowerPoint).
- File extensions: .docx Word, .xlsx Excel, .pptx PowerPoint, .pdf portable document, .jpg image.
- Internet: URL is the address of a resource; HTTP/HTTPS is the transfer protocol; a browser renders pages; a search engine indexes them; LAN is local, WAN spans distances.
Worked example
A spreadsheet has 10 in A1, 20 in A2 and 30 in A3. What does =SUM(A1:A3)/3 return?
A1:A3 is a range covering all three cells. SUM gives 60; dividing by 3 gives 20, the mean. If the formula is copied down one row with relative references, it becomes =SUM(A2:A4)/3; adding dollar signs ($A$1:$A$3) would lock the range instead.
Marks-losing traps
- Treating 1 KB as 1000 bytes in exam options - the correct answer is 1024.
- Confusing Ctrl+Z (undo) with Ctrl+Y (redo).
- Mixing up ROM (read-only, retains data without power) with RAM.
- Assuming an email password protects against viruses; antivirus software and firewalls do that job.