Intro and Chapter 1 Data representation

Question 1

What are the major components of a personal computer (PC)?

Answer 1

Computer case, computer case fan, motherboard, central processing unit (CPU), CPU cooling fan, power supply unit (PSU), random access memory (RAM), graphics card, hard drive (or SSD), optical drive (often without)

Question 2

What is the purpose of a computer case?

Answer 2

Stores all other components, prevents too much dust getting into them

Question 3

What is the purpose of a computer case fan?

Answer 3

Spins to keep components within case cool

Question 4

What is the purpose of a motherboard?

Answer 4

Allows components to be connected and communicate, allows them to receive power from PSU

Question 5

What is the purpose of a central processing unit (CPU)?

Answer 5

Responsible for operation of each fetch-decode-execute cycle carried out

Question 6

What is the purpose of a CPU cooling fan?

Answer 6

Cools CPU and prevents it from getting too hot, keeping it at best temperature to operate

Question 7

What is the purpose of a power supply unit (PSU)?

Answer 7

Powers motherboard to allow it to pass power to other components

Question 8

What is the purpose of random access memory (RAM)?

Answer 8

Temporarily stores data waiting to be processed

Question 9

What is the purpose of a graphics card?

Answer 9

Responsible for producing images seen on computer screen

Question 10

What is the purpose of a hard drive?

Answer 10

Permanently stores all files and software used

Question 11

What do most computers have to store files and software permanently? (choice)

Answer 11

A hard disk drive (HDD) or a solid state drive (SSD)

Question 12

What is the purpose of an optical drive?

Answer 12

Device in which optical media, like CDs, is inserted into, to be read by the computer

Question 13

What is hexadecimal, what does it use and why is it used?

Answer 13

A base-16 number system using values 0-9 and characters A-F, used to represent values for programmers, takes up less space on screen or paper, easier for programmers to read, write, understand, easier to debug and locate errors in data

Question 14

What is binary and what does it use?

Answer 14

A base-2 number system using the values 0 and 1, where the units increase by the power of 2

Question 15

What is analogue data?

Answer 15

A continuous stream of data processed by humans

Question 16

What is a logic gate and what data can they process?

Answer 16

A very small component in a computer system controlling electricity flow that can only process digital data

Question 17

What is digital data and what does it use?

Answer 17

Discrete data that only has values 1 and 0

Question 18

What is a register?

Answer 18

A small component in a computer system used to temporarily store data

Question 19

What is denary and what does it use?

Answer 19

A base-10 number system using values 0 - 9

Question 20

What values does a computer system use?

Answer 20

Binary number system

Question 21

How is a binary number referred to in relation to the number of bits it has, and what are these?

Answer 21

4-bit binary number has 4 values either 1 or 0, 8-bit binary number has 8 values either 1 or 0

Question 22

How do you convert a denary number to binary?

Answer 22

Compare the denary number to the first (leftmost) binary unit, if the denary is greater subtract the binary unit from it, write a 1 in that position, and move to the next binary unit. If the denary is smaller, write a 0 and move on with no subtraction. Repeat until the end of the binary units is reached

Question 23

How do you convert a binary number to denary?

Answer 23

Add together all units in the binary number represented by the value 1

Question 24

How are denary numbers converted to hexadecimal generally?

Answer 24

Denary numbers less than 16 can be directly converted to hexadecimal, greater than 16 numbers generally converted to binary first, then to hexadecimal, using 4-bit binary numbers

Question 25

How is hexadecimal converted to denary?

Answer 25

Hexadecimal numbers less than 16 can be converted to denary directly, greater than 16 generally converted to binary first, then to denary, using 4-bit binary numbers

Question 26

What is a MAC address?

Answer 26

Unique address given to a computer at the manufacturing stage, used to identify the computer

Question 27

How does binary addition work?

Answer 27

Uses four rules: 0+0=0; 1+0=1; 1+1=10 (2 is 10 in binary); 1+1+1 = 11 (3 is 11 in binary)

Question 28

What is an overflow error?

Answer 28

A type of error which occurs when a number larger than what a register can store is generated

Question 29

What is a logical binary shift and what do they do?

Answer 29

Logical binary shift moves binary values in number to left or right; leftward shift doubles number, rightward shift halves number; some binary values removed and empty spaces created with each shift

Question 30

What is a potential problematic effect of a logical binary shift?

Answer 30

Vital bits can be removed from the register, therefore data can be lost. Consequently, leftward and rightward shifts don’t always double and halve the number

Question 31

How is a negative number represented in binary?

Answer 31

Method of two’s complement used; take positive number in binary, invert all values in binary (1s and 0s swapped); 1 added to result; outcome is binary representation of negative number using two’s complement method