Memory And Storage

Question 1

Features of primary storage ?

Answer 1

.Very quick because it is directly accessed by the CPU
. Small storage size
E.g: RAM and ROM

Question 2

What is virtual memory and a benefit of virtual memory ?

Answer 2

. Is when unused data in the RAM is moved to the HDD(Hard disk drive ) so that new data can be transferred into the RAM
. A benefit of virtual memory is that more programmes can be run at the same time with less system slow down

Question 3

Features of a magnetic storage ?

Answer 3

. Most common storage for computers
. It uses a read/write head to move the nanometres above the disk platter and uses the magnetic field of the platter to read / edit the data

+ large capacity , cheap durable and portable
- slower access speed then solid state but faster than optical

Question 4

Features of optical storage ?

Answer 4

It uses a laser to project beams of light onto a spinning disc , allowing it to read data from a CD or DVD
+ portable and cheap
- slowest access speed , low capacity , not durable( dis is very fragile and can scratch)

Question 5

What is secondary storage ?

Answer 5

Non volatile storage that is used to save and store data that can be accessed repeatedly

Question 6

Features of Solid state drive ?

Answer 6

+ Fast access speed , portable , durable , high capacity
- expensive
E.g USB flash drive and SD cards

Question 7

What is lossy compression ?

Answer 7

I.s a compression that uses and algorithm to analyse a file and remove data that cannot be heard or seen by humans permenatly and the data cannot be converted back tom its original form.

.This is to reduce file size
.Lossy compression is only used in : images , sounds and videos

Question 8

Lossless compression?

Answer 8

Lossless compression reduces size of files without permanentley removing any data
This is send for files

Question 9

How to record sound ?

Answer 9

Amplitude ( height) of the analogue sound wave is measured and recorded in binary at specific intervals.

Question 10

What is metadata?

Answer 10

Additional about a file
. Colour depth
. Resolution
. Height of pixels
. Width of pixels

Question 11

What is a character set?

Answer 11

A table that matches together a character and a binary value

Question 12

Examples of character sets ?

Answer 12

ASCII- uses one byte (8 bits) which only gives 256 possible characters which is enough for English language but cannot be used for other languages and symbols
. ASCCI uses small memory

UNICODE-uses two bytes (16 bits) which 65 ,536 possible characters . Extra bytes allows more languages and symbols and emojis to be represented
Uses large memory