SF Prep
11 Computer Awareness — Common Notes 🕒 Updated 2026-10-17
Common Notes SSC CGL · CHSL · Police · Bank · Railway Chapter 11

🔤 Abbreviations, Shortcuts & File Extensions

Frequently asked computer abbreviations, Windows/MS Office keyboard shortcuts and file extensions — in one place.

📌 1. Important Abbreviations

Short formFull form
ALUArithmetic Logic Unit
BIOSBasic Input Output System
CD-ROMCompact Disc Read Only Memory
CPUCentral Processing Unit
DNSDomain Name System
DPIDots Per Inch
EEPROMElectrically Erasable Programmable Read Only Memory
FTPFile Transfer Protocol
GUIGraphical User Interface
HTMLHyperText Markup Language
HTTPHyperText Transfer Protocol
ICIntegrated Circuit
IPInternet Protocol
ISPInternet Service Provider
LANLocal Area Network
LEDLight Emitting Diode
MICRMagnetic Ink Character Recognition
MODEMModulator Demodulator
OCROptical Character Recognition
OMROptical Mark Recognition/Reader
OSOperating System
PDFPortable Document Format
RAMRandom Access Memory
ROMRead Only Memory
SMTPSimple Mail Transfer Protocol
SQLStructured Query Language
SSDSolid State Drive
UPSUninterruptible Power Supply
URLUniform Resource Locator
USBUniversal Serial Bus
VGAVideo Graphics Array
Wi-FiWireless Fidelity (popular expansion)
WWWWorld Wide Web
JPEGJoint Photographic Experts Group
GIFGraphics Interchange Format
PNGPortable Network Graphics
MP3MPEG Audio Layer III
UPIUnified Payments Interface
NICNational Informatics Centre / Network Interface Card
C-DACCentre for Development of Advanced Computing
⚠️ Exam Traps:
  • OMR = Optical Mark; OCR = Optical Character.
  • URL = Uniform Resource Locator (not Link).
  • UPS = Uninterruptible Power Supply.

📌 2. Keyboard Shortcuts

ShortcutAction
Ctrl+C / Ctrl+X / Ctrl+VCopy / Cut / Paste
Ctrl+Z / Ctrl+YUndo / Redo
Ctrl+ASelect all
Ctrl+S / F12Save / Save As
Ctrl+PPrint
Ctrl+N / Ctrl+ONew file / Open
Ctrl+W / Ctrl+F4Close current window/tab
Alt+F4Close the program
Alt+TabSwitch between open programs
Win+DShow desktop
Win+EFile Explorer
Win+LLock the computer
Ctrl+Shift+EscTask Manager
F1Help
F2Rename selected file
F5Refresh / slide show
PrtScScreenshot
Ctrl+Home / Ctrl+EndStart / end of document
Browser shortcutAction
Ctrl+TNew tab
Ctrl+Shift+TReopen closed tab
Ctrl+Shift+NIncognito / private window (Chrome)
Ctrl+HHistory
Ctrl+DBookmark
Ctrl+JDownloads
⚠️ Exam Traps:
  • In Word Ctrl+E = centre; in a browser Ctrl+D = bookmark.
  • F2 = rename (Windows); F7 = spelling (Word).

📌 3. File Extensions

ExtensionFile type
.exeExecutable program (Windows)
.txtPlain text (Notepad)
.docx / .xlsx / .pptxWord / Excel / PowerPoint
.pdfPortable Document Format
.jpg / .png / .gif / .bmpImages
.mp3 / .wavAudio
.mp4 / .avi / .mkvVideo
.zip / .rarCompressed archive
.html / .htmWeb page
.py / .java / .cPython / Java / C source code
.csvComma-separated values (tabular data)
.apkAndroid app package
💡 Memory Tip: The extension tells the file type and which program opens it.

📌 4. Practice MCQs

📝 Practice MCQs (prepared by SF Prep — not PYQs)
Q1. The full form of BIOS is: Practice
(A) Binary Input Output System
(B) Basic Input Output System
(C) Basic Internal Operating System
(D) Built-in Input Output Software
Correct answer: (B)
BIOS checks the hardware at start-up and loads the OS.
Q2. The full form of UPS is: Practice
(A) Universal Power Supply
(B) Unlimited Power Source
(C) Uninterruptible Power Supply
(D) United Power System
Correct answer: (C)
A UPS supplies power from a battery when mains power fails.
Q3. The full form of GUI is: Practice
(A) Global User Interaction
(B) General User Interface
(C) Graphic Universal Input
(D) Graphical User Interface
Correct answer: (D)
OSs like Windows provide a GUI with icons and menus.
Q4. The full form of PDF is: Practice
(A) Portable Document Format
(B) Printable Document Format
(C) Public Data File
(D) Personal Document File
Correct answer: (A)
PDF was developed by Adobe.
Q5. In JPEG, "J" stands for: Practice
(A) Java
(B) Joint
(C) Junction
(D) Joined
Correct answer: (B)
JPEG = Joint Photographic Experts Group.
Q6. The full form of USB is: Practice
(A) Universal System Board
(B) Unique System Bus
(C) Universal Serial Bus
(D) Unified Serial Board
Correct answer: (C)
USB is a standard plug-and-play port.
Q7. The full form of C-DAC is: Practice
(A) Computer Development and Control
(B) Central Department of Advanced Computers
(C) Centre for Digital Applied Computing
(D) Centre for Development of Advanced Computing
Correct answer: (D)
C-DAC Pune built the PARAM supercomputers.
Q8. The full form of UPI is: Practice
(A) Unified Payments Interface
(B) Universal Payment Interface
(C) United Payment Internet
(D) Unique Payment ID
Correct answer: (A)
UPI was developed by NPCI.
Q9. The Windows shortcut to lock the computer is: Practice
(A) Win+D
(B) Win+L
(C) Win+E
(D) Alt+F4
Correct answer: (B)
Win+L = lock; Win+D = desktop; Win+E = File Explorer.
Q10. The shortcut to switch between open programs is: Practice
(A) Ctrl+Tab
(B) Shift+Tab
(C) Alt+Tab
(D) Win+Tab only
Correct answer: (C)
Alt+Tab switches between open windows.
Q11. The shortcut to close the active program is: Practice
(A) Ctrl+F4
(B) F4
(C) Shift+F4
(D) Alt+F4
Correct answer: (D)
Alt+F4 closes the program/window.
Q12. The key to rename a selected file in Windows is: Practice
(A) F2
(B) F1
(C) F5
(D) F7
Correct answer: (A)
F2 = rename.
Q13. The shortcut to redo an undone action is: Practice
(A) Ctrl+Z
(B) Ctrl+Y
(C) Ctrl+R
(D) Ctrl+U
Correct answer: (B)
Ctrl+Z = undo; Ctrl+Y = redo.
Q14. The browser shortcut to reopen a recently closed tab is: Practice
(A) Ctrl+T
(B) Ctrl+W
(C) Ctrl+Shift+T
(D) Ctrl+H
Correct answer: (C)
Ctrl+T = new tab; Ctrl+Shift+T = reopen closed tab.
Q15. The browser shortcut to bookmark the current page is: Practice
(A) Ctrl+B
(B) Ctrl+M
(C) Ctrl+K
(D) Ctrl+D
Correct answer: (D)
Ctrl+D = bookmark; Ctrl+H = history; Ctrl+J = downloads.
Q16. A file with the ".exe" extension is a/an: Practice
(A) Executable program
(B) Image file
(C) Text file
(D) Audio file
Correct answer: (A)
.exe files run programs in Windows.
Q17. Which of these is a compressed-file extension? Practice
(A) .txt
(B) .zip
(C) .mp3
(D) .docx
Correct answer: (B)
.zip and .rar are compressed archives.
Q18. The extension of an Android app file is: Practice
(A) .exe
(B) .ipa
(C) .apk
(D) .app
Correct answer: (C)
APK = Android package; iPhone uses .ipa.
Q19. Which of these is an audio file extension? Practice
(A) .mp4
(B) .csv
(C) .png
(D) .wav
Correct answer: (D)
.wav and .mp3 are audio; .mp4 is video; .png is an image.
Q20. The function of Ctrl+A is: Practice
(A) Select all
(B) Align
(C) Add page
(D) Save all
Correct answer: (A)
Ctrl+A selects all content.

📝 Practice questions

Computer Awareness — Practice MCQs (Bilingual) Ch 11: Abbreviations & Shortcuts | संक्षिप्त रूप व शॉर्टकट
📝 Test this chapter Practice questions

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