Binary and hex

Question 1

Why do computers use binary to represent all forms of data?

Answer 1

Any form of data needs to be converted to binary to be processed by a computer(only understands two forms: on or off)
Data is processed using logic gates and stored in registers

Question 2

Explain the difference between the binary and denary number systems

Answer 2

Binary
base 2 system
2 digits (0 and 1)
place values are powers of 2

Denary
base 10 system
has 10 digits (0-9)
place values are powers of 10

Question 3

What are the binary place values for a byte?

Answer 3

128 64 32 16 8 4 2 1

Question 4

What is the largest value that can be stored in 8 bits?

Answer 4

255

Question 5

How many bits in a byte?

Answer 5

8

Question 6

How many bits in a nibble?

Answer 6

4

Question 7

What is a register?

Answer 7

A register is a small amount of internal memory
Used for fast reading and writing
It is temporary/volatile (loses data once there is no power)

Question 8

What is hexadecimal?

Answer 8

Base 16 number system
16 choices of digits (0-9, A-F)
Place values are powers of 16

Question 9

Why do we use hexadecimal?

Answer 9

Easier for programmers to read and understand
Conversion to binary easier than denary to binary
Takes up less space when displayed or printed
Faster than binary for entering numbers

Question 10

Where is Hexadecimal used?

Answer 10

HTML colour codes e.g. red = #FF0000
Display MAC (Media Access Control) addresses e.g. 01-23-45-67-89-AB-CD
Display ASCII or Unicode values e.g. %41 = 65 = A
Display error codes e.g. error #404 page not found
Display memory dumps e.g. 5F 3A 09 F1