1.1.3 input and output

Question 1

what is an input device?

Answer 1

a peripheral used to provide data and control signals to a computer system

Question 2

what is a barcode?

Answer 2

a means of representing data in a machine-readable form

Question 3

what are check digits used for?

Answer 3

validation

Question 4

what are check digits?

Answer 4

an extra digit or character added to the end of long code

Question 5

how are check digits used?

Answer 5

applying an algorithm to the other digits, the long code is entered, the check digit is calculated and compared to the check digit at the end of the code

Question 6

what are the advantages of barcode readers?

Answer 6

theyre common - reliable and well understood

Question 7

what are qr codes used for?

Answer 7

providing a link to a particular page or website etc

Question 8

what are the advantages of qr over barcode?

Answer 8

higher storage capacity

Question 9

how are qr codes read?

Answer 9

codes are captured and read by taking an image with a dedicated scanner or a mobile device

Question 10

what are rfid used for?

Answer 10

allows data to be transmitted wirelessly over radio waves

Question 11

what are the two parts of a rfid system?

Answer 11

a tag and a reader

Question 12

where are rfids used

Answer 12

id cards, library cards, transport systems, track animals (identification)

Question 13

how do passive devices work?

Answer 13

no power supply, device is powered by radio energy transmitted by the reader - energy from the transmitter activates the chop

Question 14

what is the range of passive devices?

Answer 14

up to 1 metre

Question 15

how do active systems work?

Answer 15

small battery within the tag - will transmit its identifier at regular intervals

Question 16

what is the range of active systems?

Answer 16

up to 200 meters

Question 17

what are examples of manual input systems?

Answer 17

keyboard, mouse

Question 18

what are examples of automated input systems?

Answer 18

sensor

Question 19

what is an output device?

Answer 19

peripherals that reproduce or display data and information from a computer system

Question 20

what are the 4 types of printer?

Answer 20

inkjet printer, laser printer, plotter, 3D printer

Question 21

what type of ink and paper is used with an inkjet printer?

Answer 21

liquid ink - black/white or colour
high end can handle specialist paper at very high resolutions

Question 22

what printer is the most suitable for printing photographs?

Answer 22

inkjet printer - produces rich colours

Question 23

what are inkjet printers used for?

Answer 23

photographers and at home - low upfront cost

Question 24

what is a disadvantage of inkjet printers?

Answer 24

the cost of ink is high

Question 25

where are laser printers used?

Answer 25

the workplace

Question 26

what are the advantages of laser printers over inkjet?

Answer 26

faster - one whole page at a time, high spec - capable of producing hundreds of pages per minute

Question 27

what do laser printers use to print?

Answer 27

a powdered ink called toner

Question 28

what type of image can a laser printer print?

Answer 28

very good for text, but not good for photos - difficult for deep rich colours

Question 29

how does a plotter work?

Answer 29

uses one or more pens to draw an image - pens are lifted or applied to the paper as required

Question 30

what are the advantages of plotters?

Answer 30

produces very precise drawings, can handle very wide paper, allows repeated layers to be printed

Question 31

where are plotters used?

Answer 31

engineering and architectural practices

Question 32

what do 3D printers use and how do they work?

Answer 32

filament - usually in the form of plastic-based resin which is heated and printed layer by layer to form a solid object

Question 33

what are the two types of display screens?

Answer 33

lcd screens and led displays

Question 34

what are the advantages of liquid crystal display?

Answer 34

low cost, most common display

Question 35

where are lcd used?

Answer 35

standard desktop and laptop computers

Question 36

what are the advantages of light emitting diode displays?

Answer 36

uses less power than lcd, so led are cheaper and more environmental friendly

Question 37

what are oled screens?

Answer 37

organic light emitting diode - a varient on led displays

Question 38

what are the advantages of oled over led?

Answer 38

lighter and more flexible

Question 39

where would oled be used?

Answer 39

phones and tablets

Question 40

what are impact printers?

Answer 40

produce characters by striking the paper

Question 41

what are the disadvantages of impact papers?

Answer 41

noisy, more expensive, slower

Question 42

what are the steps of laser printers?

Answer 42

1. bitmap image of the page is created
2. negative charge is applied to the print drum and then the laser is used to change the polarity on the drum in line with the bitmap image
3. drum is exposed to positively charged toner, which is attracted to the negatively charged areas of the drum
4. sheet of paper is passed under the drum and toner is transferred onto the paper
5. passes to the fusing stage to ensure that the toner sticks to the paper