Basics of Computers and Applications - CBT 2
What the domain tests
This section checks working knowledge of computer fundamentals rather than programming: hardware and software, memory and storage units, generations of computers, operating systems, MS Office (Word, Excel, PowerPoint), internet and networking basics, email, and cyber safety.
Core knowledge
- Hardware: CPU (ALU + control unit + registers), input devices, output devices, primary memory (RAM volatile, ROM non-volatile) and secondary storage (HDD, SSD, optical, pen drive).
- Units: 1 byte = 8 bits; 1 KB = 1024 bytes; 1 MB = 1024 KB; 1 GB = 1024 MB; 1 TB = 1024 GB.
- Generations: first vacuum tubes (ENIAC), second transistors, third integrated circuits, fourth microprocessors, fifth artificial intelligence.
- Shortcuts: Ctrl+C copy, Ctrl+X cut, Ctrl+V paste, Ctrl+Z undo, Ctrl+Y redo, Ctrl+S save, Ctrl+P print, F2 rename, Alt+Tab switch windows.
- Networking: LAN is confined to a building, WAN spans countries, the internet is a network of networks; HTTP, FTP and SMTP are protocols.
Worked example
Convert binary 1101 to decimal. Write place values from the right: 1×2⁰ = 1, 0×2¹ = 0, 1×2² = 4, 1×2³ = 8. Sum: 1 + 0 + 4 + 8 = 13. Reversing the method gives decimal 13 as binary 1101, confirming the conversion.
Traps that cost marks
Treating 1 KB as 1000 bytes in exam questions - the standard answer is 1024. Saying RAM is non-volatile; it loses contents on power-off, whereas ROM retains them. Mixing ROM (read-only, holds firmware) with cache (fastest, smallest memory). And confusing a compiler (translates the whole program at once) with an interpreter (line by line).