Input and output devices

• What is the storage capacity range for magnetic storage?


  500GB to 10TB.
• How does optical storage represent binary information?


  When light is shone onto a pit, it is reflected, meaning it bounces back to the reading device. This is what represents a 0 (zero).

  
  

  When light is shone onto a land, it is scattered, or dispersed in different directions, rather than being reflected. This is what represents a 1 (one).
• What is the read/write speed comparison among storage types?


  Optical is the slowest, followed by magnetic, then flash storage.
• What is the primary characteristic of ROM?


  It is non-volatile and retains its contents when the computer is turned off.
• What is the primary function of RAM?


  To store data currently being used and the operating system.
• What are the benefits and drawbacks of virtual storage?


  Benefits:

  • Accessible from anywhere with internet
  • Cost-effective
  • scalable
  • Easy data recovery

  
  

  Drawbacks:

  • Slow access with poor internet
  • Potential costs for additional storage
  • Risk of data security issues if provider does not have security measures
• What are the applications of different types of sensors?

  • Temperature: Control heating systems, monitor environmental temperature
  • Moisture: Monitor soil dampness, air dampness
  • Light: Control street lighting, window blinds
  • Infra-red: Automatic wipers, burglar alarms
  • Pressure: Weigh vehicles, forecast weather
  • Acoustic: Monitor noise levels
  • Gas: Monitor CO₂/O₂ levels
  • pH: Monitor acidity levels
  • Magnetic field: Direction in smartphones, CD player motors
• What are the types of printers and their characteristics?

  • Inkjet: Common, cheaper, but ink is expensive and can smear.
  • Laser: Fast, reliable, excellent quality, but expensive.
  • Dot matrix: Noisy, poor quality, mainly used in warehouses as very cheap.
• What are the uses of 3D printing?


  • Medical implants and devices
  • Prototyping for products
  • Customization in clothing
  • Aircraft components
  • Dentures and molds
• What is the function of a barcode scanner?


  It scans barcodes and converts them into digital data for processing by a computer.
• What are some applications of barcode scanners?


  They are used for scanning items in shops, package tracking, and scanning tickets at events.
• What does RFID stand for?


  Radio Frequency Identification.
• How does RFID technology work?


  It uses radio waves to automatically identify and track tags attached to objects.
• What is a sensor?

  A device that detects and measures physical changes in the environment.
• What are some examples of sensors?

  Motion sensor, oxygen sensor, glucose sensor, temperature sensor.
• What is the purpose of an actuator?

  It is a motor used to control a mechanism.
• In what applications are actuators commonly used?

  They are used in robotic arms, door locks, and automatic doors and gates.
• What does a 3D printer do?


  It creates physical objects based on a digital model by layering material.
• What are some products that can be created using a 3D printer?

  Physical prototypes, spare parts, medical implants, and prosthetics.
• What are the key differences between LCD and OLED screens?

  LCD:

  • 5 to 15 mm thick
  • Lifespan: Longer than OLED
  • Requires LED backlighting so higher power consumption
  • Viewing angle reduces color accuracy at acute angles
  • Usually cheaper
  • Used in older smartphones, mobile devices and budget televisions
  • OLED:
  • 
    
  • 0.9 to 2.5 mm thick
  • Lifespan: Shorter than LCD
  • Generates its own light so brightness may vary and is less than high-end LCD displays
  • Almost 180-degree viewing angle
  • Usually more expensive
  • Used in television, foldable and flexible screens
• What does RAM stand for?


  Random Access Memory.
• What does ROM stand for?


  Read Only Memory.
• What is stored in RAM?


  Data/ instructions currently in use and operating system.
• What happens to the contents of RAM when the power is turned off?


  The contents are lost because RAM is volatile memory.
• What is the role of the BIOS during startup?


  The BIOS takes over the startup process after the CPU executes initial boot-up instructions.
• What are the main functions of the BIOS?


  1. POST (power-on-self test) - Diagnostic checking of hardware
  2. Initialise Hardware - Initialise and configure hardware components
  3. Load Boot Loader - Loads the operating system into RAM
  4. Pass control to OS - Transfer control to the operating system
  5. Set System Configurations - Set dates, time, hardware configurations and boot options
  6. Error handling - Instructions for handling errors
  7. Security checks - Verify operating system's integrity and authenticity
• What is virtual memory?


  It is a section of secondary storage that acts as temporary RAM when the RAM is full.
• What are the advantages and disadvantages of virtual memory?


  Advantages:

  • Store more data
  • More applications can be open
  • No need to install more RAM

  
  

  Disadvantages:

  • Computer may hang (be delayed)
  • More time spent transferring data than processing
  • Disk thrashing / high rate of disk access
  • Virtual memory may break with excessive access
• What is the difference between primary and secondary storage?

  • Primary Storage: Directly accessible by the CPU (e.g., RAM and ROM).
  • Secondary Storage: Long-term, non-volatile storage (e.g., hard disk, CD-ROM).
• How does a hard disk drive (HDD) work?


  It rotates magnetic platters at high speeds under a read/write head on an actuating arm. The combination of the arm and rotating platter allows the read/write head to access any part of the platter.
• What are the components of a hard disk drive?


  Platters, tracks, sectors, and read/write heads.
• What happens when a computer needs to read or write data on a hard disk drive?

  The read/write heads move across the surface of the platters to access the stored data.
• What is an input device?


  Hardware components that allow users to interact with a computer system
• What are some examples of input devices?


  • Keyboard
  • Mouse
  • Touchscreen
  • Microphone
  • Webcam
  • Scanner
  • Game Controller
  • Graphics Tablet
  • Biometric Devices
  • Barcode Reader
  • Joystick
• What is the purpose of a scanner?


  Digitises physical documents or images for computer processing
• What are biometric devices used for?


  Security purposes to verify a user's identity
• What is an output device?


  Hardware components that present information from a computer system to the user
• What are some examples of output devices?


  • Monitor
  • Printer
  • Speakers
  • Headphones
  • Projector
  • Braille Display
  • Plotter
  • Virtual Reality (VR) Headset
  • Computer-Controlled Machinery
• What does a printer do?


  Produces a hard copy of digital documents or images
• What is the purpose of a projector?


  Projects the computer's display onto a large screen or wall