1.4.1 Data Types

Question 1

What is a bit?

Answer 1

Either a 1 or 0
We use bits to represent the two electronic states: on and off.

Question 2

How many bits are in a byte?

Answer 2

8 bits in a byte

Question 3

How many bits are in a nibble?

Answer 3

4 bits in a nibble

Question 4

How many values can be represented with n bits?

Answer 4

2^n

Question 5

How many bytes are in a kibibyte?

Answer 5

1024

Question 6

What is the power of kibi?

Answer 6

2^10

Question 7

What is the power of mebi?

Answer 7

2^20

Question 8

What is the power of gibi?

Answer 8

2^30

Question 9

What is the power of tebi?

Answer 9

2^40

Question 10

What is the power of pebi?

Answer 10

2^50

Question 11

What is the power of exbi?

Answer 11

2^60

Question 12

What is the power of zebi?

Answer 12

2^70

Question 13

What is the power of yobi?

Answer 13

2^80

Question 14

What is a character set?

Answer 14

A collection of characters, each assigned a unique binary value

Question 15

How many bits does ASCII use per character?

Answer 15

7

Question 16

How many bits does extended ASCII use per character?

Answer 16

8

Question 17

How many bits does UNICODE use to represent a character?

Answer 17

16

Question 18

What’s the difference between UNICODE and ASCII?

Answer 18

ASCII only represents english characters whereas UNICODE represents all symbols even from other languages

Question 19

What is a real/float?

Answer 19

Used to store decimal numbers and to store very large/small values

Question 20

What is a character/char?

Answer 20

A single letter, number or special characters typically represented in ASCII

Question 21

What is a string?

Answer 21

A collection of characters. Anything enclosed in quotation marks is a string

Question 22

What is boolean/bool?

Answer 22

A boolean variable can only take the value TRUE or FALSE

Question 23

What is an integer?

Answer 23

A whole number

Question 24

What is casting?

Answer 24

The process of changing one data type into another

Question 25

What are the bases of denary, binary and hex?

Answer 25

Denary - 10
Binary - 2
Hex - 16

Question 26

Why use hex over binary?

Answer 26

More likely to make mistakes when writing in binary than hex
Easier to work with

Question 27

How does hex represent numbers?

Answer 27

Uses 0-9 to represent 0-9
Uses letters A-F to represent 10-15

Each part is represented by a nibble ( 4 bits )

Question 28

Convert 229 to hex

Answer 28

1110 0101
14 5
E5

Question 29

Convert F3 to denary

Answer 29

1111 0011
243

Question 30

How does sign and magintude work in binary?

Answer 30

The most signifcant bit represents whether the number is positive or negative
1 is negative
0 is positive

Question 31

What are 2 problems with sign and magnitude?

Answer 31

Addition of numbers is trickier for the computer
Reduced number of bits avaible for represent our number
Max number that we can make with 8 bits is 127

Question 32

What is two’s complement?

Answer 32

A way of storing positive and negative numbers by the most significant bit taking the negative value of itself.

Question 33

What are the 2 methods of writing in twos complement?

Answer 33

1 - write the positive version of the number, flip the bits and add one
2 - add the numbers, usually using the MSB as a negative version of itself ( for example -128 ), and keep adding positive numbers until its the correct number

Question 34

What is a left shift?

Answer 34

All the bits are shifted to the left
For every place value shifted, the value is doubled

Question 35

What is a right shift?

Answer 35

All the bits are shifted to the right
For every place value shifted, the value is halved.

Question 36

Why are floating-point numbers normalised?

Answer 36

To ensure that they are as precise as possible in a given number of bits

Question 37

How do you normalise a binary number?
Example:
00101 000

Answer 37

Remove extra zeros from the front (only 1 is allowed) and buff the back of the mantissa. Decrease the exponent by 1

01010 111

Question 38

How would you convert 1.75 to floating point binary?

Answer 38

Write out the fixed point: 01.11
Move the decimal point: 0.111
The mantissa: 01110
The exponent: 0001
All together: 011100001

Question 39

What happens when you increase the size of the exponent?

Answer 39

Increases the size of the number that can stored

Question 40

What happens when you increase the size of the mantissa?

Answer 40

Increases the precision of the number that can be stored