Computer Knowledge / Computer Aptitude
Computer Knowledge / Computer Aptitude
Questions here are short and definitional, with a few aptitude items: hardware and software, generations of computers, memory and storage units, operating systems, MS Office and shortcuts, internet and browsers, networking basics, databases and cyber security.
Core rules
- Units: 8 bits = 1 byte; 1 KB = 1024 bytes; 1 MB = 1024 KB; 1 GB = 1024 MB; 1 TB = 1024 GB. ROM is non-volatile, RAM is volatile.
- Generations: first - vacuum tubes; second - transistors; third - integrated circuits; fourth - microprocessors; fifth - artificial intelligence.
- Networking: LAN is confined to a building, WAN spans cities; the OSI model has seven layers; an IP address identifies a device and DNS maps a domain name to that address.
- Security: phishing is a fraudulent message that harvests credentials; a firewall filters traffic; antivirus uses signatures; ransomware encrypts data and demands payment.
- Shortcuts worth memorising: Ctrl+C/V/X copy, paste, cut; Ctrl+Z undo; Ctrl+P print; Ctrl+S save; Ctrl+F find.
Worked example
Convert the decimal number 45 to binary. Reasoning: take the largest powers of two - 32 + 8 + 4 + 1 = 45. Place 1 in the 32, 8, 4 and 1 positions and 0 in the 16 and 2 positions: 101101. Check by adding: 32 + 8 + 4 + 1 = 45.
Traps
- Bit vs byte in storage questions.
- Confusing primary memory (RAM/ROM) with secondary storage (hard disk, SSD, pen drive).
- Mixing phishing with pharming or with spam.
- Reading the shortcut key wrong when the question asks for the function, not the key.