Computer was one of the subjects my maximum marks came from. Its syllabus is limited, and the questions are factual, so it is one of the few places in the paper where full marks are realistic. Learn the tables below by heart and then practise MCQs until nothing surprises you.
What this topic covers
Windows shortcuts
| Shortcut | Action |
|---|
| Ctrl + C / X / V | Copy / Cut / Paste |
| Ctrl + Z / Y | Undo / Redo |
| Ctrl + A | Select all |
| Ctrl + S | Save |
| Ctrl + P | Print |
| Ctrl + F | Find |
| Alt + Tab | Switch between open windows |
| Alt + F4 | Close the active window |
| Windows + D | Show desktop |
| Windows + L | Lock the computer |
| Windows + E | Open File Explorer |
| Ctrl + Shift + Esc | Open Task Manager |
| F2 | Rename the selected file |
MS Word
| Shortcut | Action |
|---|
| Ctrl + B / I / U | Bold / Italic / Underline |
| Ctrl + E / L / R / J | Centre / Left / Right / Justify |
| Ctrl + H | Find and Replace |
| Ctrl + K | Insert hyperlink |
| F7 | Spelling and grammar check |
| F12 | Save As |
| Ctrl + Home / End | Go to start / end of the document |
MS Excel
- Every formula starts with =.
- A1 is a relative reference; $A$1 is an absolute reference (it doesn't change when copied).
- Common functions: SUM, AVERAGE, COUNT, MAX, MIN, IF.
- F2 edits the active cell. Ctrl + ; inserts today's date.
- A file is a workbook; each page in it is a worksheet.
MS PowerPoint
- F5: start the slideshow from the beginning. Shift + F5: from the current slide.
- Ctrl + M: new slide.
- A single page is a slide; the whole file is a presentation.
Memory units
| Unit | Equals |
|---|
| 1 nibble | 4 bits |
| 1 byte | 8 bits |
| 1 KB | 1,024 bytes |
| 1 MB | 1,024 KB |
| 1 GB | 1,024 MB |
| 1 TB | 1,024 GB |
Memory types
- RAM: primary, volatile, read-write working memory.
- ROM: primary, non-volatile; holds the start-up (BIOS) instructions.
- Cache: the fastest memory, between the CPU and RAM.
- Secondary storage: hard disk, SSD, pen drive; non-volatile.
Network terms
- LAN (a building), MAN (a city), WAN (a country or the world; the internet is the largest WAN).
- IP address: a device's address on a network. DNS turns names like houseofaspirants.in into IP addresses.
- HTTP / HTTPS: the protocol for web pages; the S means secure (encrypted).
- URL: the full address of a web page. ISP: the company that gives you internet access.
- Router joins networks; a modem converts digital signals for the line.
Basics
- Charles Babbage: father of the computer. CPU = ALU + Control Unit (+ registers).
- Input devices: keyboard, mouse, scanner, microphone. Output devices: monitor, printer, speaker.
How it is asked in the exam
- "Which shortcut opens Find and Replace in MS Word?" (Ctrl + H.)
- "1 byte = ? bits" (8.)
- "Which memory is volatile?" (RAM.)
- "$A$1 is which type of reference?" (Absolute.)
- "F5 in PowerPoint?" (Start slideshow.)
Points to remember
- Ctrl + Y is Redo in Word, not Undo.
- F12 is Save As; Ctrl + S is Save.
- Volatile = loses data without power.
Common mistakes
- Using 1,000 instead of 1,024 for memory conversion.
- Calling ROM "secondary" memory. It is primary, but non-volatile.
- Mixing up a workbook (the file) and a worksheet (the sheet).
Practise straight after reading
Use the shortcuts on a real computer while you learn them; your hands remember faster than your eyes. Then solve the Computer quizzes on this site until you score full marks twice in a row, and revise these tables after 1, 7 and 30 days.