Data representation

Question 1

Hexadecimal

Answer 1

A=10
B=11
C=12
D=13
E=14
F=15

Question 2

what is hexadecimal used for

Answer 2

MAC address
IP address
HTML colour code
error code

Question 3

what is mac address

Answer 3

media access control
unique identifier for a device on a network
48 bits

Question 4

what is ip address

Answer 4

internet protocol address
address given to a device on a network

Question 5

what is ADC

Answer 5

analogue to digital convertor
sound to binary for computer to understand

Question 6

1 byte

Answer 6

8 bits

Question 7

File size of image

Answer 7

image resolution(pixels) * colour depth(bits)

Question 8

file size of sound

Answer 8

sample rate(Hz) * sample resolution(bits) * length of sample(seconds)

Question 9

data compression

Answer 9

save storage
upload files faster
reduce time to stream

Question 10

lossy file compression

Answer 10

removes unnecessary data from file
original file cannot be recovered
loss of detail
great at reducing file size
JPEG
MPEG-4

Question 11

lossless file compression

Answer 11

original file can be reconstructed
no data will be lost
uses RLE (run length coding)

Question 12

SAMPLING RESOLUTION

Answer 12

The number of bits used to represent sound amplitude in digital sound recording, the more bits the better the accuracy but the more storage it takes

Question 13

colour depth

Answer 13

the number of bits used to represent each colour

Question 14

ASCII code

Answer 14

8 bit
represents letters, numbers and characters
1 byte per character

Question 15

Unicode

Answer 15

16 bit
represents more characters than ASCII code
up to 4 bytes per character

Question 16

sampling resolution

Answer 16

number of bits used

Question 17

sampling rate

Answer 17

number of sounds samples taken per second