Memory and Storage

Question 1

What is primary storage?

Answer 1

It’s low-capacity, internal storage that can be directly accessed by the CPU

Question 2

Why was primary storage needed?

Answer 2

Primary storage access speeds are much faster than secondary storage

Question 3

What does RAM mean and what are its features?

Answer 3

Random Access Memory
Volatile (temporary)
Stores all the programs that are currently running

Question 4

What does ROM mean and what are its features?

Answer 4

Read-Only Memory
Non-volatile
Can’t be changed
Stores boot program/ BIOS
BIOS loads operating system

Question 5

Where are programming instructions stored and what is the processing of them?

Answer 5

Stored by the RAM
It’s copied from the hard drive into the RAM which can the be processed by the CPU

Question 6

Why is virtual memory need?

Answer 6

If there isn’t enough space for all the programs in the the RAM
The Hard Drive Disk can be used as an extension -virtual memory

Question 7

What are some characteristics of primary storage?

Answer 7

Very quick as it’s accessed by CPU
Smaller storage size
Called ‘main memory’

Question 8

What are some characteristics of secondary storage?

Answer 8

Slower not directly accessed by CPU
Larger storage size
Long-term storage of data and files

Question 9

Why is secondary storage needed?

Answer 9

To save and store data that will be accessed repeatedly
Non-volatile storage

Question 10

Examples of magnetic storage:

Answer 10

Floppy disk
Magnetic tape

Question 11

What are some magnetic storage characteristics?

Answer 11

Large capacity
Cheaper than solid state
Not durable or portable
Slow access speed (faster than optical storage)

Question 12

Examples of solid state storage:

Answer 12

USB flash drives
SD card

Question 13

What are some optical storage characteristics?

Answer 13

Low capacity
Not durable
Portable
Slowest access speed

Question 14

Examples of optical storage:

Answer 14

CD
DVD
Blu-Ray

Question 15

What are some solid state storage characteristics?

Answer 15

High capacity
More expensive
Durable
Portable
Fast access speeds

Question 16

What are characteristics that can be mentioned when talking about secondary storage?

Answer 16

Capacity
Speed
Portability
Durability
Reliability
Cost

Question 17

Order the units of data storage:

Answer 17

Bit
Nibble (4 bits)
Byte (8 bits)
Kilobyte (1,000 bytes or 1KB)
Megabyte (1,000KB)
Gigabyte (1,000MB)
Terabyte (1,000GB)
Petabyte (1,000TB)

Question 18

Why must data be stored in a binary format?

Answer 18

All data is presented in binary
Everything that needs to be processed on the computer needs to be converted into a binary format so it’s understood

Question 19

How to calculate the size of a sound file?

Answer 19

Sound file size = sample rate x duration (s) x bit depth

Question 20

How to calculate the image file size?

Answer 20

Image file size = colour depth x image height (px) x image width (px)

Question 21

How to calculate the text file size?

Answer 21

Text file size = bits per character x number of characters

Question 22

What is an overflow error?

Answer 22

When a binary number is too big to be stored in the bits available

Question 23

1 binary shift to the left equals?

Answer 23

Multiply by 2

Question 24

2 binary shifts to the left equals?

Answer 24

Multiply by 4

Question 25

1 binary shift to the right equals?

Answer 25

Divide by 2

Question 26

2 binary shifts to the right equals?

Answer 26

Divide by 4

Question 27

What is a character set?

Answer 27

Collections of characters that a computer recognises from their binary representation

Question 28

What are two common character sets?

Answer 28

ASCII and Unicode

Question 29

How many characters can ASCII store?

Answer 29

256 characters as it uses 1 byte

Question 30

How many characters can Unicode store?

Answer 30

65,536 characters as it uses 2 bytes

Question 31

Compare Unicode and ASCII:

Answer 31

ASCII only has english - doesn't take up much memory space Unicode has different languages, symbols and emojis - more memory is required

Question 32

What are bitmap images made of?

Answer 32

Pixels, single coloured squares on a grid

Question 33

Each pixel has:

Answer 33

Each pixel has an individual binary which represents the colour of the pixel

Question 34

Whats the relationship between file size of an image when changing colour depth and resolution?

Answer 34

The file size gets bigger when the colour depth and resolution is increased

Question 35

What does metadata store?

Answer 35

It stores additional image information like height and width

Question 36

How are analogue sound waves stored?

Answer 36

They must be digitally recorded and converted into binary

Question 37

How would you record a sound?

Answer 37

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

Question 38

How would you get a high quality sound?

Answer 38

Many samples are taken to recreate the analogue wave as closely as possible

Question 39

What is sample rate and what is it measured in?

Answer 39

The number of times per second the amplitude of a wave is recorded In Hertz (Hz)

Question 40

What is bit depth in sound?

Answer 40

The number of bits available to represent each sample

Question 41

What is duration?

Answer 41

The number of seconds of audio the sound file contains

Question 42

What are benefits of compression of files ?

Answer 42

Files take up less space Files can be transferred faster Files can be read from or written to faster

Question 43

What is lossy compression?

Answer 43

Permanently removes data that can't be seen or heard by humans - reduces size of file

Question 44

What is lossy compression used on?

Answer 44

Images, audio, and videos

Question 45

What is lossless compression?

Answer 45

Reduces size of file without permanently removing data (can be decompressed) - bigger file size

Question 46

What is lossless compression used on?

Answer 46

Executable files (programs and games) and word documents