data representation

Question 1

what is binary?

Answer 1

1s and 0s that computers understand

Question 2

size of a bit?

Answer 2

a single binary digit (1 or 0)

Question 3

size of a nibble

Answer 3

4 bits

EG: 0101

Question 4

size of a byte?

Answer 4

8 bits

EG: 01011101

Question 5

size of a kilobyte?

Answer 5

1000 bytes

Question 6

size of a megabyte?

Answer 6

1000 kilobytes

Question 7

size of a gigabyte?

Answer 7

1000 megabytes

Question 8

size of a terabyte?

Answer 8

1000 gigabytes

Question 9

size of a petabyte?

Answer 9

1000 terabytes

Question 10

order of bits (small-large)

Answer 10

Bats -bit
Nibble -nibble
Bread -byte
Knowing -kilobyte
Mice -megabite
Give -gigabyte
Terrible -terabyte
Presents -petabyte

Question 11

what is denary?

Answer 11

standard number system
1-10

Question 12

whats the highest binary can go?

Answer 12

255

Question 13

how to convert from binary to denary?

Answer 13

add up the numbers with a 1 in their collumn

Question 14

how to convert from denary to binary?

Answer 14

subtract from left to right

Question 15

how to add binary?

Answer 15

put them into collums
start on the right add the numbers

when doing 1+1 = 10 (2) place 0 and carry 1 to the next collumn

when doing 1+1+1 = 11 (3) place 1 and carry 1 to the next column like regular addition

Question 16

what is an overflow?

Answer 16

when a number has too many bits than a CPU is expdcting

Question 17

what is a binary shift?

Answer 17

moves every bit in a binary number left or right

gaps on the ends get filled by 0s

Question 18

what is a left shift?

Answer 18

multiplies the number

for every place shifted left the number is doubled

moves LEFT

Question 19

what is a right shift?

Answer 19

divides a binary number

for every place shifted right the number is halved

moves RIGHT

Question 20

what are hexadecimal numbers?

Answer 20

uses a combination of digets and letters to represent a number

Question 21

what is the highest hex number before it becomes a letter?

Answer 21

9

Question 22

converting binary to hex?

Answer 22

split into nibbles(4s)

draw table 8,4,2,1 and fill in

for each nibble(4) add up the numbers with a 1

put hex numbers together

Question 23

what is ascii?

Answer 23

a commonly used english character set

Question 24

how to work out file size?

Answer 24

number of bits per char X num of chars

Question 25

what is a bitmap image?

Answer 25

an image made of pixels represented by binary codes

Question 26

how are colours represented in pixels in photos?

Answer 26

by binary

Question 27

what is a 1bit image?

Answer 27

made of 2 colours, 1 bit for each pixel

Question 28

what is a 2 bit image?

Answer 28

made of 4 colours, 2 bits per pixel

Question 29

how to make more shades/colours in an image?

Answer 29

increase the colour depth

Question 30

what is colour depth?

Answer 30

the number of bits used for each pixel

Question 31

what is metadata?

Answer 31

the information stored in an image file which helps the computer relate the image to binary

Question 32

examples of metadata?

Answer 32

height width colour depth resolution

Question 33

what is sample rate?

Answer 33

how many samples you take per second (sound) measured in Hz

Question 34

what is data compression?

Answer 34

temporarily/permanently removing unwanted data from a file to make it smaller while keeping it as true to the original as possible

Question 35

advantages of compressing files?

Answer 35

take up less storage on a device streaming is quicker as they take less bandwidth emails usually have restrictions

Question 36

what are the two types of compression?

Answer 36

lossy lossless

Question 37

what is lossy compression?

Answer 37

permanently removing data from a file, reducing its size

Question 38

what is lossless compression?

Answer 38

temporarily removing data to store the file then restores it to its original state when opened

Question 39

advantages of lossy compression?

Answer 39

greatly reduces the file size meaning more files can be stored take up less bandwidth so can be downloaded/streamed quicker

Question 40

disadvantages of lossy compression?

Answer 40

loses data, the file cannot be turned back to its original state cannot be used on text files as they need to keep all their information worse quality than the origional

Question 41

file type examples for lossy compression?

Answer 41

MP3 JPEG

Question 42

advantages of lossless compression?

Answer 42

there is no reduction in quality as data is only temporarily removed can be turned back to its original state can be used on text files

Question 43

disadvantages of lossless compression?

Answer 43

only a slight reduction in file size so it still takes up space on your device

Question 44

file type examples for lossless compression?

Answer 44

PNG ZIP