Computing - Data

Question 1

What is a bit?

Answer 1

One binary digit (1 or 0)

Question 2

What is the difference between a nibble and a byte?

Answer 2

A nibble is 4 bits

A byte is 8 bits

Question 3

What is a kilobyte in bytes?

Answer 3

1024 bytes

Question 4

How do you convert decimal into binary?

Answer 4

Divide the number by 2 and the remainder is the furthest digit to the right
Divide that number by 2 and the remainder is the next number and so on

Question 5

Convert the decimal 67 to binary

Answer 5

67 / 2 = 33 r 1
33 / 2 = 16 r 1
16 / 2 = 8 r 0
8 / 2 = 4 r 0
4 / 2 = 2 r 0
2 / 2 = 1 r 0
1 / 2 = 0 r 1

67 = 1000011

Question 6

How do you convert binary to decimal?

Answer 6

Make a table with the multiples of 2 going from right to left
Put the binary number in the table with one digit in each column
Add together the multiples of 2 that have a 1 under them

Question 7

Convert 11010 from binary to decimal

Answer 7

16 | 1
8 | 1
4 | 0
2 | 1
1 | 0
16 + 8 + 2 = 26

11010 = 26

Question 8

How do you add binary numbers?

Answer 8

Add like a decimal but if the result is 2, carry 1 to the next column
If the result is 3 put a 1 below AND carry 1 to the next column

Question 9

Add the binary numbers 1111 and 1100

Answer 9

1111 + 1100
1 + 0 = 1
1 + 0 = 1
1 + 1 = 0 (carry 1)
1 + 1 (+ 1) = 1 (carry 1)
(1) = 1
1111 + 1100 = 11011

Question 10

Why is getting 11011 when adding 1111 and 1100 a problem?

Answer 10

There are 5 digits in the answer and 4 digits in each of the binary numbers to be added
This is an overflow error

Question 11

What is hexadecimal?

Answer 11

Base 16 number system

Each column is worth 16 times the one to its right

Question 12

What are the digits in hexadecimal?

Answer 12

0 to 9 and then A to F

Question 13

How do you convert hex to binary?

Answer 13

Change each digit to decimal
Calculate the 4 binary digits that make up each decimal number
Put the binary digit groups together

Question 14

Convert DB (hex) to binary

Answer 14

D = 13
B = 11

13 / 2 = 6 r 1
6 / 2 = 3 r 0
3 / 2 = 1 r 1
1 / 2 = 0 r 1
13 = 1101

11 / 2 = 5 r 1
5 / 2 = 2 r 1
2 / 2 = 1 r 0
1 / 2 = 0 r 1
11 = 1011

DB = 11011011

Question 15

Describe the ASCII character set

Answer 15

Uses 7 bits (binary digits) to store each character

This allows there to be 127 different characters

Question 16

What is unicode?

Answer 16

A character set that has 107000 characters covering 90 languages

Question 17

What is a bitmapped image?

Answer 17

An image where each pixel is represented by a bit

Question 18

What is resolution?

Answer 18

The amount of pixels in a given area

It decides on the quality of the image

Question 19

What happens to a file when the resolution is increased?

Answer 19

The file size is increased

Question 20

What is colour depth?

Answer 20

The number of bits per pixel

The more bits per pixel, the better quality of the colour because more colours can be encoded

Question 21

What is metadata?

Answer 21

Data about data

Question 22

What are vector graphics?

Answer 22

Pictures that can be stored as formulae

They can enlarged to any size because the pixels change size and move in comparison to each other

Question 23

What type of energy form is sound in terms of computing?

Answer 23

Analogue

Question 24

What is sampling?

Answer 24

When a computer creates a sound wave which has only horizontal or vertical lines which is very close to the original curved sound wave

Question 25

What is bit rate?

Answer 25

The number of bits sampled per second

A higher bit rate gives a sampled sound wave which is closer to the true sound wave

Question 26

What is compression?

Answer 26

Changing a sound file so that the parts a human can’t hear are removed
This reduces the file size

Question 27

What is the instruction set of a CPU?

Answer 27

Changing data
Moving data
Controlling program flow

Question 28

What are the parts of an instruction and what do they do?

Answer 28

Operator is the process (add, subtract etc.)

Operand is the number or a memory address to where some data is stored

Question 29

With the instruction 10011101, what are the operator and operand?

Answer 29

10011101
Operator is 1001
Operand is 1101