Digital Data

Question 1

Describe how a number is converted to a binary pattern for storage in compute

Answer 1

Computers Memory can be ON or OF

On is indicated by 1 and off is indicated by 0

Data is sorted character by character with each character being represented by a code, which will consist of 1’s and 0’s and each code is sent to the CPU

Question 2

Define a Bit

Answer 2

Smallest unit of storage on a computer

it is a single digit in a binary number(0 or 1)

Question 3

Define a Byte

Answer 3

a group of 8 bits

Question 4

Define a nibble

Answer 4

A nibble is half a byte, consisting of 4 bits

Question 5

How many bytes in a kilobyte

Answer 5

1024

Question 6

How many kilobytes in Megabytes

Answer 6

1024

Question 7

How many Megabytes in a gigabytes

Answer 7

1024

Question 8

how many gigabytes in a terabyte

Answer 8

1024

Question 9

What are the two types of character representation

Answer 9

ASCII(7- bit and 8-bit)

Unicode

Question 10

Expand ASCII

Answer 10

American Standard Code for Information Interchange

Question 11

Explain ASCII(7 bit)

Answer 11

Uses 7 bits to represent each character,only 128 characters could be represented in the character set

Question 12

Explain ASCII(8 bit)

Answer 12

Uses 8 bits to represent each character, a further 128 characters can be represented in the character set, totalling 256 characters

Question 13

Explain Uni Code

Answer 13

Unicode typically uses 16 bits to represent a character and so can represent up to 65000 character

Question 14

Explain the meaning of Overflow

Answer 14

Overflow happens when computerized calculations produce an answer that it too big to represented, you have to remove the overflow to get the right answer

Question 15

Define a Variable

Answer 15

A memory location given a name used to hold data which can change value

Question 16

What is hexadecimal?

Answer 16

Numbering system which uses base 16. Expressed by digits 0-9 and letter A-F giving 16 possibilities

Question 17

What is 0+0 in binary?

Answer 17

0

Question 18

What is 1+0 in binary?

Answer 18

1

Question 19

What is 1+1 in binary?

Answer 19

10

Question 20

What is 1+1+1 in binary?

Answer 20

11

Question 21

What is 1+1+1 in binary if it is in the last column?

Answer 21

An overflow

Question 22

What is an overflow?

Answer 22

An extra bit which gets discarded so the answer is correct

Question 23

What does it mean in sign magnitude if the first number is 0 an if the first number is 1?

Answer 23

0 is positive
1 is negative

00001100 = positive
10001100 = negative

Question 24

What happens in 1’s complement?

Answer 24

Every number is flipped
1 –> 0
0 –> 1

Question 25

What happens when the numbers in 1's complement are flipped?

Answer 25

The number is the negative of the normal binary 00001100 = 12 11110011 = -12

Question 26

What happens in 2's complement?

Answer 26

Turn the normal binary to 1's complement and then add 1, this gives you the 2's complement value. It should be the negative of the normal binary value.

Question 27

What is the NOT operator?

Answer 27

It only has 1 input if x = 0 not X = 1

Question 28

What is an AND operator?

Answer 28

Can have any number of inputs. All must be true for the AND to be true X Y X AND Y 0 0 0 0 1 0 1 0 0 1 1 1

Question 29

What is the OR operator?

Answer 29

Can have any number of inputs. X Y X OR Y 0 0 0 1 0 1 0 1 1 1 1 1

Question 30

What is the XOR operator?

Answer 30

It can have any number of inputs. It is only true when only 1 of the input values is true. X Y X OR Y 0 0 0 1 0 1 0 1 1 1 1 0