Input and Output devices part 2

Question 1

5. QR Code scanners
   Advantages ~ (3)
   Operation - (advan. 1)

Answer 1

~- just scan and it will direct you to a website.
~ QR codes can be an effective way of advertising
~ QR codes can store up to 7000 digits.

Question 2

6. Digital cameras
   Advantages ~ (6)
   operation - (2)

Answer 2

Advantages:

Digital cameras are controlled by microprocessors so they can:
~ focus on image
~ operate flash
~ adjust shutter speed
~ adjust the aperture size
~ adjust the size of image
~ remove red eye

• a photo is captured when light passes through the lens onto light-sensitive cells
• the cells are made of pixels

Question 3

7. Keyboards
   Advantages ~ (1)
   Disadvantages * (2)
   Operation - (2)

Answer 3

Advantages:

~ it’s a simple way of imputing data

Disadvantages:

• they are quite slow
• you can develop Repetitive Strain Injury(RSI)

Operation:

• a keyboard is connected to a computer using USB or wirelessly(Bluetooth)
• each character has an ASCII value.

Question 4

9. Microphones

Operation - (2)

Answer 4

Operation:

• when a microphone detects sound, a diaphragm vibrates producing an electrical signal.
• the signal is transmitted to a sound card and is converted into digital data.