Computer Systems

Question 1

What is the range of numbers of 8 bit

Answer 1

-128 to 127

Question 2

What is the range of numbers of 12 bits

Answer 2

-2048 to 2047

Question 3

What is the range of numbers of 16 bits

Answer 3

-32768 to 32767

Question 4

How many characters can ASCII represent

Answer 4

256

Question 5

How many bits does a character have in ASCII

Answer 5

8

Question 6

How many characters can Unicode represent

Answer 6

65336

Question 7

How many bits does a character have in Unicode

Answer 7

16

Question 8

What is an advantage and disadvantage of using ASCII

Answer 8

Uses up less space but can only represent english alphabet

Question 9

What is an advantage and disadvantage of using Unicode

Answer 9

Can represent more symbols and letters but uses up more space

Question 10

How are things stored in bitmap graphics

Answer 10

As a grid of pixels, they are resolution dependant meaning if resized it will become blurry and the quality will go down

Question 11

What is bitdepth

Answer 11

The amount of bits in a pixel which determines the colour

Question 12

How are things stored in Vector graphics

Answer 12

Stores the object attributes of shapes, resolution independant meaning if resized the quality will the stay the same

Question 13

What are the advantages and disadvantages of using Bitmap

Answer 13

More realistic images and can be edited in fine detail
Take up more storage space and are resolution dependant meaning if they are resized the image will become pixelated

Question 14

What are the advantages and disadvantages of using Vector

Answer 14

They are resolution independant meaning they will not become pixelated when resized
You can change the order of them so positioning objects behind each other
They are not suitable for storing realistic photographic images

Question 15

What are the 3 types of buses

Answer 15

address bus
data bus
control bus

Question 16

What does the address bus do

Answer 16

Carries address info from processor to main memory
Uni-directional

Question 17

What does the data bus do

Answer 17

Carries data to and from the processor
Bi-directional

Question 18

What is the fetch execute cycle

Answer 18

The processor sets up the address bus with the required address.
The processor activates the read line on the control bus
An instruction is fetched from the memory location using the data bus and stored in the memory data register
The instruction in the instruction register is then translated and executed

Question 19

How could you increase system performance

Answer 19

Increase clock speed
Increase amount of cores
Increase data bus width
Increase cache

Question 20

How can intelligent systems reduce environment impact in heating systems

Answer 20

Use sensors to detect if people in room and turn on when motion detected
Learn from previous days, time the heating should turn on
use smartphone apps to turn on/off

Question 21

How can intelligent systems reduce environment impact in traffic systems

Answer 21

satnav can be used to guide people away from congestion to stop constant stopping and starting which burns fuel

Question 22

How can intelligent systems reduce environment impact in car management systems

Answer 22

Intelligent sys control engine, turn off when not moving and back on when you stop braking
Sensors optimise engine performance by controlling air to fuel ratio

Question 23

What are the symptoms, effects and motives of a DOS attack

Answer 23

Can’t access site, the system is very slow
Actual users can’t access to their accounts or info they need on the site
Personal - attacker may have been fired by company
Political - may be state sponsored
Financial - attacker may want ransom money

Question 24

What is encryption

Answer 24

Encryption encodes data making it scrambled and unintelligible
Data is encrypted with Public Key and Decrypted with Private Key

Question 25

What is a digital signature

Answer 25

Code attached to message that identifies sender, it authenticates the sender, ensures data that has been sent isn’t altered

Question 26

What is a digital certificate

Answer 26

Package of info that identifies user, includes user’s name, email, country and name of organisation that issued certificate and Public Key
Certificate acts as a middle man, both users trust and confirms identity of users
When sender sends data, they send certificate, receiver can check certificate that sender is legit