2.4 number STORAGE

Question 1

what base system is binary?

Answer 1

base 2 (2 possible values)

Question 2

what base system is denary?

Answer 2

base 10 (10 possible values)

Question 3

what base system is hexadecimal?

Answer 3

base 16 (16 possible values)

Question 4

what values are in hexadecimal?

Answer 4

0 -> 9 as well as A B C D E and F

Question 5

when does an overflow error occur?

Answer 5

when a binary value is too large to be stored in the bits available

Question 6

what is binary shift?

Answer 6

multiplication and division of binary numbers
left: multiply
right: divide

Question 7

what is a character set?

Answer 7

a table that matches together characters and binary values

Question 8

which can store more characters? (ascii or unicode)

Answer 8

unicode

Question 9

how do you remember which stores more characters?

Answer 9

unicode - uni = universal so all languages

Question 10

why is ascii limited?

Answer 10

it only uses one byte therefore only 256 characters

Question 11

what about unicode makes more powerful than ascii?

Answer 11

2 bytes: 65,536 possible characters

Question 12

file size of text files?

Answer 12

bits per character * number of characters

Question 13

bitmap images are made of

Answer 13

pixels

Question 14

what represents the colour of each pixel?

Answer 14

a binary value

Question 15

what happens to the quality of a bitmap image when it is scaled larger?

Answer 15

it is visibly decreased greatly

Question 16

how do you calculate the file size of a bitmap

Answer 16

file size = resolution x colour depth

Question 17

what is metadata?

Answer 17

additional data about a file

Question 18

example of metadata

Answer 18

• height in pixels
• width in pixels
• colour depth
• resolution
• geo location
• data created
• last edited
• file type
• author details

Question 19

how do we record sound?

Answer 19

the amplitude of the analogue sound wave is measured and recorded in binary at specific intervals

Question 20

define sample rate

Answer 20

the number of times per second the amplitude of the sound wave is measured

Question 21

when sample rate is increased, so does _____ ______

Answer 21

audio quality
(or file size, but try to say audio quality)

Question 22

what is sample rate measured in?

Answer 22

kHz or Hz

Question 23

digital sampling is _______ and not continuous like analogue waves

Answer 23

discrete*

Question 24

digital sampling is discrete and not _________ like analogue waves

Answer 24

continuous

Question 25

what is the bit depth?

Answer 25

the number of bits available to represent each sample

Question 26

the higher the bit depth, the more bits available so therefore

Answer 26

higher quality / it more closely resembles an analog wave

Question 27

sound file size equation

Answer 27

sound file size = sample rate * bit depth * duration