memory

Question 1

primary storage

Answer 1

volitaile with the exception of rom
computers beed primarily storage because access times are faster
primarily storage holds data and instructions
primary storage is used as short term working memory

Question 2

secondary storage

Answer 2

non volatile
large capacity

Question 3

what is ram

Answer 3

ram is primary storage that holds data and instructions that are currently in use
ram is volatile
ram is very fast
ram is read/write which means data can be read from and written to

Question 4

what is rom

Answer 4

rom is primary storage that holds the first instructions a computer needs to start up
rom contains the bios
rom is fast memory but slower than ram
rom is non volatile
rom is read only

Question 5

what is virtual memory

Answer 5

virtual memory is an extension of primary storage located on secondary storage
when ram is nearly full virtual memory is used
programs and data not currently being excuted are transferred to virtual memory
slower than ram

Question 6

why do you need secondary storage

Answer 6

long term storage of programs and data not currently in use
slower than primary storage but capacity is much higher

Question 7

common types of storage

Answer 7

magnetic
solid state
optical

Question 8

what is magnetic storage

Answer 8

magnetic storage is a type of non volatile media that uses magnets to store binary 0s and 1s

Question 9

advantages and disadvantages of magnetic storage

Answer 9

advantages
high capacity
low cost per gb
decent speed

disadvantages
not very durable
inconvenient to be portable
not very reliable
and noisy

Question 10

what is solid state storage

Answer 10

solid state storage is a type of non volatile media that used electronic circuits to store binary 0s and 1s

Question 11

advantages and disadvantages of solid state storage

Answer 11

advantages
high storage
very fast
durable
portable

disadvantages
high cost
not reliable

Question 12

optical storage what is it

Answer 12

optical storage is a type of non volatile media that uses lasers to burn the surface of a disk creating pits and lands suitable for storing binary 0s and 1s

Question 13

advantages and disadvantages of optical storage

Answer 13

advantages
low cost
durable
protable

disadvantages
low capacity
slow
not reliable

Question 14

from smallest to largest the units of storage

Answer 14

bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte

4 bits make a nibble
8 bits makes a byte
1000 bytes is a kilo byte
1000 kilo bytes is a megabyte
1000 megabytes is a giga byte
1000 gigabytes is a terabyte
1000 terabytes is a petabyte

Question 15

hexadecimal values

Answer 15

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

Question 16

what is an overflow error

Answer 16

an overflow error is occurs when a binary value is larger than the bits available

Question 17

name two character sets

Answer 17

ASCII unicode

Question 18

what does the quality of the image depend on

Answer 18

the total amount of pixels

Question 19

equation for file size

Answer 19

file size= resolution x colour depth

Question 20

colour depth meaning (bit depth)

Answer 20

the number of bits that are used to represent each pixels colour

Question 21

what is meta data

Answer 21

additional data about a file

Question 22

what happens if you change colour depth

Answer 22

image size decreases and quality decreases

Question 23

what happens if you lower the resolution

Answer 23

lowering the resolution can lead to a quality decrease and an image size decrease.

Question 24

analogue sound waves must be what

Answer 24

analogue sound waves must be digitally recorded and stored in binary to record the sound the amplitude (height)of the analogue sound must be measured and recorded in binary at specific intervals.

Question 25

how to get the highest quality sound for sound waves.

Answer 25

to get the highest quality sound many samples are taken to recreate the analogue wave as closely as possible

Question 26

what is sample rate?

Answer 26

sample rate is the number of times per second the amplitude of the sound wave is measured. higher the sample rate better the quality but higher the file size because there is more data to store

Question 27

what is bit depth?

Answer 27

the number of bits used to represent each sample. higher the bit depth better the quality but higher the file size.

Question 28

how to calculate file size

Answer 28

file size=sample rate x bit depth x duration

Question 29

what are the types of compression

Answer 29

lossy compression lossless compression

Question 30

what is compression and what are the benefits?

Answer 30

to compress a file means to make it smaller benefits include files take up less storage files can be read and written to quicker files can be transferred quicker

Question 31

what is lossy compression?

Answer 31

lossy compression is the removal of data from a file that can be seen/heard sometimes depending on what was removed.and it is permanent.

Question 32

what are the advantages and disadvantages of lossy compression

Answer 32

advantages file is smaller file is transferred quicker via internet can be used for images audio or files. disadvantages data is permanently deleted so you cannot go back to the original form of the file. may also be noticeable that the data has been removed so quality may be worse.

Question 33

what is lossless compression?

Answer 33

lossless compression reduces the file size without removing any data. because of this the file can turn to its original form since no data is lost so no quality is lost.

Question 34

advantages and disadvantages of lossless compression.

Answer 34

advantages data is not lost file can return to original form file size decreases disadvantages usually only used with files that would not work if data was removed e.g programs, games , word documents and executable files