1.2.4 Data Storage

Question 1

Denary

Answer 1

Standard number system with 10 different digits

Question 2

Which digits are in denary

Answer 2

0,1,2,3,4,5,6,7,8,9

Question 3

What base is denary

Answer 3

Base-10

Question 4

Which digits are in binary

Answer 4

0,1

Question 5

Overflow error

Answer 5

When a result requires more bits than the computer expects during binary arithmetic

Question 6

How do computers show that an overflow error has occurred

Answer 6

Overflow flags

Question 7

How do computers deal with overflow errors

Answer 7

They store the extra bits somewhere else

Question 8

What can overflow errors cause

Answer 8

-Loss of data
-Loss of accuracy in calculation
-Crash software

Question 9

Binary shift

Answer 9

Every bit in a binary number is moved left/right a number of places

Question 10

What are gaps in a binary shift filled in with

Answer 10

0s

Question 11

What happens to a binary number in a left shift

Answer 11

It is doubled

Question 12

What happens to a binary number in a right shift

Answer 12

It is halfed

Question 13

What may a binary left shift cause

Answer 13

A binary overflow

Question 14

Which base is hexadecimal

Answer 14

Base-16

Question 15

Advantages of hexadecimal

Answer 15

-Simpler to remember large numbers
-Hex numbers are shorter so less chance of input errors
-Easier to convert to binary

Question 16

Which digits are in hexadecimal

Answer 16

0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F

Question 17

Hexadecimal A in denary

Answer 17

10

Question 18

Hexadecimal B in denary

Answer 18

11

Question 19

Hexadecimal C in denary

Answer 19

12

Question 20

Hexadecimal E in denary

Answer 20

14

Question 21

Hexadecimal F in denary

Answer 21

15

Question 22

What are words and strings made of

Answer 22

Alphanumeric Characters

Question 23

Examples of alphanumeric characters

Answer 23

Upper and lowercase letters, the digits 0-9 and symbols (?,+,£…)

Question 24

Why can’t computers directly process alphanumeric characters

Answer 24

They only process binary code

Question 25

How do computers process characters

Answer 25

They are converted into binary code

Question 26

Character set

Answer 26

Collections of characters that a computer recognises from their binary representation

Question 27

What happens when you press a button on your keyboard

Answer 27

A binary signal is sent to the computer telling it which key you pressed. The computer then uses the character set to translate the binary code into a particular character

Question 28

What is each character of ASCII represented in

Answer 28

7-bit binary code

Question 29

Why is an extra bit (0) added to the front of binary code in ASCII

Answer 29

It means each ASCII character is 1 byte

Question 30

How many characters are there in ASCII

Answer 30

128

Question 31

Unicode

Answer 31

-Tries to cover every possible character or symbol that might be written -Uses multiple bytes for each character

Question 32

Why is Unicode so useful

Answer 32

It covers all major languages (including those which use a completely different alphabet)

Question 33

What is significant about the first 128 lines of Unicode

Answer 33

They are the same as ASCII

Question 34

ASCII bits per character

Answer 34

8

Question 35

Text file size (in bits) formula

Answer 35

Bits per character x number of characters

Question 36

Bitmap image

Answer 36

Made up of lots of tiny dots (pixels)

Question 37

What is the colour of each pixel represented by in a bitmap image

Answer 37

Binary code

Question 38

Colour depth

Answer 38

Number of bits used for each pixel represented

Question 39

Total number of colours formula

Answer 39

2^n (where n=colour depth)

Question 40

Image resolution

Answer 40

The number of pixels in the image

Question 41

Image resolution formula

Answer 41

Width x height

Question 42

Image file size (in bits) formula

Answer 42

Image resolution x colour depth

Question 43

Metadata

Answer 43

Information stored in an image file which helps the computer recreate the image on screen from the binary data in each pixel

Question 44

What is included in metadata

Answer 44

-File format -height -width -colour depth -resolution

Question 45

What would happen if an image did not have metadata

Answer 45

Devices would not be able to display them as intended

Question 46

Analogue signal

Answer 46

Pieces of continually changing information

Question 47

What type of signal before being recorded

Answer 47

Analogue

Question 48

What do computers convert analogue signals into

Answer 48

Digital data

Question 49

Why must analogue signals be converted into digital data

Answer 49

Computers must be able to read and store sound files

Question 50

What converts analogue signals to digital data

Answer 50

Analogue to digital converters

Question 51

Sampling

Answer 51

The process of converting analogue to digital

Question 52

What happens when analogue signals are converted into digital data

Answer 52

Lots of data is lost

Question 53

How to improve the quality of digital data

Answer 53

Take samples more regularly

Question 54

Sample rate

Answer 54

The number of samples you take in a second

Question 55

What is sample rate measured in

Answer 55

Hz

Question 56

What is sample rate also called

Answer 56

Sampling frequency

Question 57

Bit depth (sound files)

Answer 57

The number of bits available for each sample

Question 58

Sound file size (in bits) formula

Answer 58

Sample rate (Hz) x bit depth x duration(seconds)

Question 59

What happens when you increase the sample rate

Answer 59

-The analogue recording is sampled more often -The samples will be better quality -The samples will more closely match the original -The file size will increase

Question 60

What happens when you increase the bit depth of a sound file

Answer 60

-Quieter sounds are picked up -Closer to the quality of the analogue recording -File size increases