Computer Aptitude
Scope of the section
Computer Aptitude is mostly awareness plus simple arithmetic on memory and number systems. Expected areas: hardware and software, input and output devices, generations of computers, memory units and hierarchy (bit, byte, KB, MB, GB, TB), RAM versus ROM, operating systems, common MS Office shortcuts, file extensions, internet terminology (URL, HTTP and HTTPS, ISP, browser, IP address, LAN and WAN), email basics, and cyber security concepts such as phishing, malware, firewall and antivirus.
Prepare the small, certain facts thoroughly: the full form of standard abbreviations, which device is input or output, and where data sits in the memory hierarchy. Practise binary-to-decimal and decimal-to-binary conversion, since a single easy question of this type is common.
Traps: treating ROM as volatile when it retains data while RAM does not; using 1,000 instead of 1,024 in memory-unit questions; confusing Ctrl+S (save) with Ctrl+P (print) or Ctrl+Z (undo); mixing HTTP with its secure form HTTPS; and confusing a browser with a search engine - the browser is software, the search engine is a website.
Worked example: convert binary 1011 to decimal. Place values 8, 4, 2 and 1 give 1×8 + 0×4 + 1×2 + 1×1 = 11. For hexadecimal, group the binary digits in fours from the right and convert each group separately. Rule of thumb: every step in the memory chain is ×1,024 - 1 KB is 1,024 bytes - even though storage manufacturers market drives using 1,000. In the exam, always use 1,024.