comp

Question 1

Define ‘hardware’

Answer 1

All physical parts of a computer system.

Question 2

Define ‘software’

Answer 2

All the computer programs of a computer system.

Question 3

What is system software?

Answer 3

Runs a computer’s hardware and applications.
operating system
utility software

Question 4

What is utility software?

Answer 4

Keeps computing device in working order and safe.

Question 5

What is an operating system?

Answer 5

Allows hardware to interact with applications.

Question 6

What is application software?

Answer 6

Helps user perform specific tasks
runs on operating system

Question 7

What are the roles of an operating system?

Answer 7

Allows user to interact with hardware, manages memory, file management, communicates between application and hardware.

Question 8

What is the role of the ALU?

Answer 8

Arithmetic logic unit, carries out calculations and logical decisions.

Question 9

What is the role of the CU?

Answer 9

Controls how data and instructions move around the CPU.

Question 10

What is the role of the clock?

Answer 10

Synchronizes all components using a steady pulse.

Question 11

What is the role of buses?

Answer 11

Collections of wires that transport instructions/data around components.

Question 12

What is the Fetch-Decode-Execute cycle?

Answer 12

Fetches data or instruction from RAM, inspects and decodes it using registers, executes it, and goes back to RAM to grab more data.

Question 13

What factors affect CPU performance?

Answer 13

Clock speed, cache size, number of cores.

Question 14

What is main memory?

Answer 14

Internal memory for temporary things. RAM, cache, registers are volatile; ROM is non-volatile.

Question 15

What is secondary storage?

Answer 15

External memory for permanent things, all non-volatile.

Question 16

What is the role of secondary storage?

Answer 16

To permanently store data, data backup, archiving, cost efficiency.

Question 17

How does optical storage work?

Answer 17

A laser burns pits and lands, a less powerful laser shines and reflects representing instructions in binary.

Pros: thin, lightweight, portable; Cons: low capacity, slow to access data; Examples: CD-R/RW, DVD-R/RW, Blu-ray.

Question 18

How does magnetic storage work?

Answer 18

Magnetic fields magnetize sections of a metal spinning disk. A read/write head moves across the disk surface.

Pros: high storage capacity, quick access, cheap, portable; Cons: moving parts can be unreliable; Examples: Hard disk drive, tape.

Question 19

How does solid-state storage work?

Answer 19

Flow of electricity forces electrons into floating gates, changes measured as 1 or 0.

Pros: very quick access, no noise, durable; Cons: limited read/write cycles, expensive; Examples: SSDs, memory sticks, flash memory cards.

Question 20

Define ‘cloud storage’

Answer 20

Remote servers that store data, accessible over the internet.

Question 21

What are the pros and cons of cloud storage?

Answer 21

Pros: access files from anywhere, automatic backup, easy collaboration; Cons: costly, requires internet access, can be hacked.

Question 22

Define an embedded system and give an example.

Answer 22

A computer system with a dedicated function inside a larger mechanical system.

Examples: traffic lights, washing machines, fitness trackers.

Question 23

What is a low level definition?

Answer 23

Languages that a CPU understands, in binary and difficult to debug/program.

Question 24

What is a high level definition?

Answer 24

Languages that are close to natural languages of humans.

Question 25

What is the hierarchy of languages?

Answer 25

Python/Java/Pseudocode, Source Code, Assembly language, Machine Code.

Question 26

What are interpreters?

Answer 26

Translates source code into machine code, one line at a time. ## Footnote Used for debugging.

Question 27

What are compilers?

Answer 27

Translates source code into machine code all at once. ## Footnote Quicker and takes less space; source code compiled on one system won’t work on another.

Question 28

What are assemblers?

Answer 28

Translates assembly language into machine code.

Question 29

Define ‘number base’

Answer 29

A system for representing numbers using a specific number of digits.

Question 30

What is the role of hexadecimal?

Answer 30

Number base of 16, representing large numbers, more readable than binary, defining colors.

Question 31

How to convert ASCII to Unicode?

Answer 31

Copy over ASCII number, put 2 slashes, convert value into hexadecimal.

Question 32

Define ‘character set’

Answer 32

A collection of characters that a computer system can use to represent text.

Question 33

Define ‘pixel’

Answer 33

Short for ‘picture element’, it’s the smallest unit of information in a digital image/display.

Question 34

Define ‘analogue’

Answer 34

The physical quantities/form.

Question 35

Define ‘data compression’

Answer 35

The process of reducing the size of data by encoding it using fewer bits than the original representation.

Question 36

Define ‘algorithm’

Answer 36

A series of steps to complete a task.

Question 37

What is an assignment?

Answer 37

Colour ← blue; CONSTANT PI ← 3.142; colour = ('blue'); PI = 3.142.

Question 38

What are arithmetic/relational/boolean operations?

Answer 38

9 DIV 5 = 1 (without the remainder); 9 MOD 5 = 4 (the remainder itself).

Question 39

What is random number generation?

Answer 39

Python: 'import random'; variable = random.randint(1, 10); Pseudocode: variable = RANDOM(1, 10).

Question 40

Define ‘efficiency’

Answer 40

The speed and the memory required to store an algorithm.

Question 41

How to compare efficiencies?

Answer 41

Less lines, more efficient.

Question 42

Define ‘data type’

Answer 42

Classification of data which tells the system how the user intends to use the data.

Question 43

Define ‘iteration’

Answer 43

A programming statement that repeats code.

Question 44

Define ‘selection’

Answer 44

A programming concept that allows the flow of a program provided a condition is met.

Question 45

Define ‘subroutine’

Answer 45

A small separate program that executes a commonly used specific task within the main program.

Question 46

How to find the length of a string?

Answer 46

LEN('computer science') in pseudocode.

Question 47

How to use the index?

Answer 47

Example = ('ritisha'); print (example[3]). ## Footnote *prints ‘i’*

Question 48

How to cast one data type to another?

Answer 48

Python: write data type and open bracket; Pseudocode: CHAR_TO_INT.

Question 49

How to make substrings?

Answer 49

Example = ('Newcastle'); substring = example [1:2:7]. ## Footnote Starts at position 1, goes in 2s, ends at position 6, not 7.

Question 50

What are the pros of subroutines?

Answer 50

Saves time, saves code, possibilities for decomposition, easier to read, maintain, debug, and use in other programs.

Question 51

What is the role of parameters?

Answer 51

Enable you to have temporary values for local variables in subroutines.

Question 52

How to do ‘subroutines’?

Answer 52

Python: 'def' variable:; Pseudocode: 'PROCEDURE' variable; content of procedure; 'END PROCEDURE'.

Question 53

Define ‘data structure’

Answer 53

A way of storing and organizing data to make it easier to access and manipulate.

Question 54

Define ‘global variables’

Answer 54

A variable that is accessible throughout the entire program, including inside functions.

Question 55

Define ‘local variables’

Answer 55

A variable that is defined within a function and can only be accessed inside that function.

Question 56

Define ‘validation’

Answer 56

Checking that the data entered is correct and the right data type.

Question 57

Define ‘authentication’

Answer 57

Checking that the person is who they claim to be.