Input and output devices

• What are the two categories of input devices?

  Manual input devices and automatic input devices
• Why are keyboards designed ergonomically?

  To accommodate human design limitations
• What is a health issue associated with keyboard use?

  Repetitive Strain Injury (RSI)
• How do keyboards detect key presses?

  By closing switches in a grid or matrix
• What does the keyboard's processor compare to identify a key?

  A table of character keys in its ROM
• What is a concept keyboard?

  A keyboard that allows custom programming of keys
• Where might touch-sensitive keyboards be used?

  In fast food restaurants for quick orders
• How do touch screens work?

  By detecting touch through a plastic cover with wires
• What is a graphics tablet used for?

  To draw with a stylus on a touch-sensitive pad
• What is the main advantage of an optical mouse?

  It is accurate and doesn't collect dirt
• What do web cams and microphones capture?

  Images and sound
• How does an optical mouse detect movement?

  By analyzing reflected light signals
• How does a microphone convert sound?

  By converting sound waves into voltage
• What is the sample rate in microphone usage?

  The frequency of voltage sampling per second
• What happens to the voltage sampled by the sound card?

  It is converted into a binary number
• What do scanners capture from images?

  Images divided into pixels
• How does a scanner reconstruct an image?

  By storing information about each pixel
• What is the effect of higher resolution in scanning?

  Better detail but larger file size
• What is a video capture card used for?

  To convert analogue video signals to digital
• What do digital cameras store images on?

  Memory instead of film
• What is a key consideration when using digital cameras?

  The amount of memory available
• What is a benefit of using digital camcorders over analogue?

  Better quality and no loss when copied
• What is a common use of biometric devices?

  Fingerprint scanning for identification
• What is a concern regarding biometric data?

  Data storage and access security
• How do biometric systems enhance security?

  By using unique physical traits for identification
• What are the main types of manual input devices discussed?

  • Keyboards
  • Touch-sensitive keyboards
  • Touch screens
  • Graphics tablets
  • Optical mice
  • Scanners
  • Web cams
  • Microphones
  • Digital cameras
  • Camcorders
  • Biometric devices
• What are the advantages and disadvantages of using digital cameras?

  Advantages:

  • Store images digitally
  • Immediate viewing and retaking
  • Add extra information easily
  • Combine images into albums

  
  

  Disadvantages:

  • Memory-intensive
  • Limited by resolution settings
• What are the features of digital camcorders?

  • Zoom capabilities
  • Sound recording
  • Night viewing
  • Time-lapse photography
  • Picture stability software
  • Special effects
• What are the key functions of microphones in data input?

  • Convert sound waves to voltage
  • Sample voltage at intervals
  • Store digital sound files
  • Playback through speakers
• What are the steps involved in scanning an image?

  1. Place image on flat bed
  2. Cover the image
  3. Light passes over the image
  4. Image divided into pixels
  5. Information stored and reconstructed
• What are the main uses of web cams?

  • Capture images for video calls
  • Used in VOIP applications
  • Integrated with microphones for sound
  • Facilitate communication over the Internet
• What are the main concerns regarding biometric devices?

  • Data storage and access
  • Security against hacking
  • Privacy issues
  • Reliability of recognition
• What are the two categories of input devices?

  Manual input devices and automatic input devices
• What is the primary function of input devices?

  To get data into a computer system
• What are the characteristics of QWERTY keyboards?

  • Used for manual data entry
  • Efficient for trained users
  • Can be slow for untrained users
  • Designed ergonomically to reduce strain
• What health issue is associated with prolonged keyboard use?

  Repetitive Strain Injury (RSI)
• How do keyboards detect key presses?

  By closing switches in a grid
• What does the keyboard's processor do when a key is pressed?

  It identifies the key and sends information
• What are touch-sensitive keyboards and their applications?

  • Use touch-sensitive areas for input
  • Common in fast food restaurants
  • Useful in dirty environments
  • Customizable for specific needs
• How do touch screens work?

  By detecting finger touches on the screen