Computer Science Paper 1 Topic 2 Memory & Storage

Question 1

What is RAM

Answer 1

Random access memory
It stores open programs and files
Volatile
Rewritable

Question 2

What is ROM

Answer 2

Read only memory
Stores start up instructions for computer
Non volatile
Read only

Question 3

What is primary storage

Answer 3

Type of storage accessed by the cpu directly so very quick
Smaller than secondary
Sometimes called main memory
Includes ram and rom

Question 4

What is secondary storage

Answer 4

It is a slower as it’s not directly accessed by cpu
It’s larger in size
It’s used for long term storage of data and file as its non volatile

Question 5

What is virtual memory

Answer 5

It is a type of storage used when ram is full rather than the computer stopping. Files and data are stored in virtual memory but if virtual memory is used the system will slow down

Question 6

Name three types of secondary storage

Answer 6

Optical
Magnetic
Solid state

Question 7

Name an example of optical storage

Answer 7

CDs
DVDs

Question 8

Name an example of magnetic storage

Answer 8

Hard disk drive
Floppy disk

Question 9

Name an example of solid state storage

Answer 9

Memory stick
SSDs
SD cards

Question 10

Advantages and disadvantages of magnetic storage

Answer 10

Large capacity
Fast access speed slower than solid state
Portable
Durable
Not very reliable can faulter

Question 11

Advantages and disadvantages of optical storage

Answer 11

Small capacity
Slow access speed
Light pretty portable
Not very durable easily scratched
Decently reliable
Very cheap

Question 12

Advantages and disadvantages of solid state storage

Answer 12

Large capacity
Durable
Portable as very small
Expensive
Reliable

Question 13

Why must data be in binary format

Answer 13

I’m able to process and execute instructions they must be in a format the computer understands like binary

Question 14

What is the affect of a binary shift left

Answer 14

Doubles the number

Question 15

What is the affect of a binary shift right

Answer 15

Halves the number

Question 16

What is character set

Answer 16

A table that matches together a character and a binary value

Question 17

What is ascii

Answer 17

A character set
Not much memory space
8 bits 256 possible characters 2^8
Only enough for English laungage

Question 18

What is uni code

Answer 18

A character set
More memory space
16 bits 65536 possible characters 2^16
Different launages to be represented

Question 19

What are images made of

Answer 19

Pixels

Question 20

What is resolution

Answer 20

How many pixels in an image
Higher resolution better quality but bigger file size

Question 21

What is colour depth

Answer 21

Number of different colours in an image

Question 22

What is meta data

Answer 22

Data that is stored in an image like location, bits per pixel, length or height of image

Question 23

How do you calculate file size of an image

Answer 23

Size = colour depth * image length * image width

Question 24

How do you calculate file size of a character set

Answer 24

File size = bits per character * number of characters

Question 25

How is sound transferred to digital format

Answer 25

Sound is transmitted through that air as a analogue wave this is sampled the height of the wave is measured at regular intervals each sample is stored as binary number the binary number for each sample is stored sequentially

Question 26

How do you calculate file size of sound

Answer 26

File size = sample rate * duration * bit depth

Question 27

What is lossy compression

Answer 27

File size is reduced however quality is also reduced

Question 28

What is lossless compression

Answer 28

File size is reduced however quality stays the same

Question 29

What is sample rate

Answer 29

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

Question 30

If sample rate increases what happens

Answer 30

Sound quality will increase and so will file size

Question 31

What is bit depth

Answer 31

Number of bits to represent each sample