Computer Knowledge
Scope
Computer Knowledge tests fundamentals rather than programming depth: hardware, memory, operating systems, MS Word/Excel/PowerPoint, internet and networking, database concepts and cyber security. Questions are usually one-line factual or shortcut-based.
Core concepts
- Bit = binary digit; 8 bits = 1 byte; 1 KB = 1024 bytes.
- RAM is volatile and holds running programs; ROM is non-volatile firmware storage.
- OS functions include process, memory, file and device management.
- IPv4 uses 32-bit addresses; IPv6 uses 128-bit addresses.
- HTTP/HTTPS, FTP, SMTP and DNS are common protocols.
- In spreadsheets, relative references change on copy; absolute references use $.
- A firewall filters traffic; phishing is a social-engineering attack; malware includes viruses, worms and Trojans.
Worked example
Convert binary 1011₂ to decimal. Reasoning: write place values from the right: 1×2⁰ = 1, 1×2¹ = 2, 0×2² = 0, 1×2³ = 8. Sum = 11. So 1011₂ = 11₁₀. For a spreadsheet, =SUM(A1:A5) adds five cells; =$A$1 locks both column and row when copied.
Traps
Saying 1 KB = 1000 bytes when the exam uses 1024; confusing RAM with a hard disk; mixing HTTP with HTML; and treating a Trojan as a self-replicating worm. In Excel, do not confuse SUM with COUNT, which counts numeric cells only, or with COUNTA, which counts non-empty cells.