Topic 3 -Fundamentals of Data Representation

Question 1

What is denary?

Answer 1

0 - infinite

Question 2

What is binary?

Answer 2

0’s and 1’s

Question 3

What does a left binary shift do?

Answer 3

x2

Question 4

What does a right binary shift do?

Answer 4

Divide 2

Question 5

0 + 0 =

Answer 5

0

Question 6

0 + 1 =

Answer 6

1

Question 7

1 + 1 =

Answer 7

0 carry 1

Question 8

1 + 1 + 1=

Answer 8

1 carry 1

Question 9

1 + 1 + 1 + 1=

Answer 9

0 carry 1 two spaces

Question 10

What is hexadecimal?

Answer 10

0 -9
A = 10
B = 11
C=12
D = 13
E =14
F = 15

Question 11

What is ASCII?

Answer 11

A character set that uses 7 bits to represent numbers, symbols and characters

Question 12

What is a disadvantage of ASCII?

Answer 12

Only in one language

Question 13

What is unicode?

Answer 13

A character set based of ASCII for backwards compatibility that represents all major languages.
Uses 16 bits

Question 14

What is resolution?

Answer 14

Total number of pixels

Question 15

What is a pixel?

Answer 15

The smallest element of an image

Question 16

What is a bitmap?

Answer 16

A grid arrangement of pixels

Question 17

What is colour depth?

Answer 17

The number of bits needed to store all the colours

Question 18

What is the formula for representation size?

Answer 18

Representation size = no. of pixels x colour depth

Question 19

What is metadata?

Answer 19

Data about data

Question 20

What happens if you enlarge a bitmap?

Answer 20

It becomes pixelated

Question 21

What are vector graphics?

Answer 21

Images that never become pixelated because they are redrawn to size.
Eg. logos

Question 22

What is amplitude?

Answer 22

The ‘height’ of the sound wave

Question 23

What is sampling?

Answer 23

Taking a reading at regular intervals

Question 24

What is sample rate?

Answer 24

The number of samples per second

Question 25

What is sample rate measure in?

Answer 25

Hertz

Question 26

What is sample size/ resolution?

Answer 26

The number of bits per sample

Question 27

What is the formula for representation size?

Answer 27

Sample rate x sample size x duration

Question 28

What does compression do?

Answer 28

Makes files smaller therefore reducing storage space

Question 29

What is lossy compression?

Answer 29

When you remove unimportant data that can never be restored

Question 30

What is lossless compression?

Answer 30

When you restore data it is the same as original

Question 31

What is run-length-encoding?

Answer 31

Grouping repeated data

Question 32

How do Huffman trees work?

Answer 32

They calculate the frequency of characters and create a binary tree

Question 33

What does the left side of a Huffman tree represent?

Answer 33

0

Question 34

What does the right side of a Huffman tree represent?

Answer 34

1