P2 T1 L2 - Binary and Hex

Question 1

How is data stored in computers?

5 points

Answer 1

1. Data is held in computers in storage locations built using electrical circuits with switches
2. The circuits have 1 of 2 states: Low voltage (closed), High voltage (open)
3. So, we need 2 symbols to represent these 2 states: 0 (low), 1 (high)
4. This is the Binary system
5. All data is stored this way, that is: Programs, Numbers, Characters, Sound, Pictures

Question 2

What is bit?

2 points

Answer 2

1. Stands for Binary Digit

2. Stores 0 or 1

Question 3

What is byte?

1 point

Answer 3

1. A group of 8 bits

Question 4

What is word?

1 point

Answer 4

1. A group of bytes

Note, a 64-bit machine has a word size of 64 bits (8 bytes)

Question 5

What is a number system?

2 points

Answer 5

1. A Number System is any notation for representing numbers
2. The notation is the symbols used to represent different values

In this part of the course, you need to know about:
Binary - base 2
Denary - base 10
Hexadecimal - base 16

Question 6

What are pure unsigned binary numbers?
(1 point)

An odd number always ends in _
An even number always ends in _

Answer 6

1. The basic number system used to identify positive integers.

1
0

Question 7

What formula do you use to find the largest binary number possible from a certain number of bits?

Answer 7

2^n -1

Question 8

What are the 16 symbols in hexadecimal

Answer 8

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F

Question 9

What are the values of (Hexadecimal) A and F in pure binary and denary

Answer 9

A - 1010 (pure binary) -10 (denary)

F - 1111 (pure binary) - 15 (denary)

Question 10

How do you convert unsigned binary to Hexadecimal?

3 steps

Answer 10

1. Break the binary number into 4-bit nibbles
2. Translate each nibble into the hex equivalent
3. Write the hex digits together

Question 11

How do you convert Hexadecimal to unsigned binary?

2 steps

Answer 11

1. Convert each hex character to a 4-bit nibble

2. Combine the nibbles into a single 8 bit binary value

Question 12

How do you convert denary into hexadecimal?

2 steps

Answer 12

1. Take the denary number and translate it to binary

2. Take the binary number and translate it to hexadecimal

Question 13

Why is hexadecimal used?

3 points

Answer 13

1. A way of writing large binary (or denary) numbers in a shorter number of digits
2. Easier for humans to read than pure binary (The computer still just understands it as binary)
3. Useful since all bit combinations in a 4 bit binary number may be represented in a single character – you would need 2 denary digits to do this