chap. 2: hardware + output devices

Question 1

hardware: mouse

Answer 1

• uses LEDs + DSPs to collect input
• scroll wheel uses a series of clicks
• button state: on or off

Question 2

hardware: keyboard

Answer 2

• switches, turning on and off a circuit
• ASCII recorded by computer

Question 3

hardware: RFID

Answer 3

• unique barcodes
• wide range
• integrated circuit + antenna
• active(battery + provides feedback) + passive(provides no feedback)

Question 4

hardware: microphones + sound cards

Answer 4

• compression waves –> electrical energy
• vibrations –> current –> representing sound waves
• ADC for conversion

Question 5

hardware: scanners

Answer 5

• generally uses light as raw data which is turned into binary
• images in bitmap(grids of individual pixels) form
• differentiates through light + dark areas

Question 6

output: video cards(display adapters)

Answer 6

• contains GPU
• RAM
• transmits digital data via DVI
• also transmits data via HDMI

Question 7

output: data projectors

Answer 7

• strong light source
• transmissive projectors(shines light through small, transparent image)
• reflective projectors(reflects light off the surface)

Question 8

output: LCD monitors

Answer 8

• liquid crystals: matter between a state of liquid and solid, used to polarize screens
• requires separate light source
• TFT: thin film transistors

Question 9

output: printers

Answer 9

• data through USB/bluetooth
• laser printers: static electricity used to attract ink to paper
• inkjet printers: drops dots of ink onto paper, four colour process

Question 10

output: sound cards

Answer 10

• converts binary audio samples into signals for speakers(usually analog)
• binary samples produce by RAM + DAC

Question 11

output: speakers

Answer 11

• creates audio sample through magnet + coil
• the current created from the coil and magnet mimics the digital audio

Question 12

output: CRT + plasma screens

Answer 12

CRT: uses negatively charged electrons to activate phosphor coating
Plasma: emits UV light to activate phosphor when circuit is created