External Hardware

Question 1

How does a digital camera work

Answer 1

1. Shutter opens and lets light in
2. Light focussed onto a sensor
3. Sensor stores pixels
4. Light is converted into electrons & the amount of charge is stored
5. Data stored on flash memory which uses programmable ROM
6. Data can be manipulated

Question 2

What does a digital camera store

Answer 2

Still & moving images in digital form (binary)

Question 3

What is an advantage of a digital camera

Answer 3

It can be processed further

Question 4

What does rgb mean

Answer 4

Cameras will either have three sensors or three filters

Question 5

Where is data stored in a digital camera

Answer 5

Compressed files
Or
RAW (uncompressed) files

Question 6

How does a bar code scanner work

Answer 6

1. LED or laser passed over image
2. Light sensor used to measure intensity of reflected light, converted into a current
3. White reflects most & black reflects least
4. Analogue converted to digital

Question 7

What is the term when the light intensity measure is converted into a current

Answer 7

Waveform

Question 8

Is waveform analogue or digital

Answer 8

Analogue

Question 9

What does RFID stand for

Answer 9

Radio frequency identification

Question 10

What device is used for RFID

Answer 10

Tags

Question 11

What might a tag contain

Answer 11

Chip
Antennae
Battery

Question 12

What do chips do

Answer 12

Contains data about the item & a modem to modulate and demodulate radio signals

Question 13

What do antennas do

Answer 13

Sends and receives signals

Question 14

Active tags

Answer 14

Have a small battery

Question 15

Passive tags

Answer 15

Pick up electromagnetic power when in range of an RFID reader