Representing data

Question 1

In computers, how is data and instructions represented?

Answer 1

Binary

Question 2

What type of number system is binary?

Answer 2

Base two (0 and 1)

Question 3

What is each digit in a binary number called?

Answer 3

Bit

Question 4

Convert 10110 to denary

Answer 4

22

Question 5

Convert 0100 1001 to denary

Answer 5

73

Question 6

What is a group of 8 bits called?

Answer 6

Byte

Question 7

How many bytes are in a kilobyte?

Answer 7

1024

Question 8

How many kilobytes are in a megabyte?

Answer 8

1024

Question 9

How many megabytes are in a gigabyte?

Answer 9

1024

Question 10

How many gigabytes are in a terabyte?

Answer 10

1024

Question 11

What is half a byte (4 bits) called?

Answer 11

Nibble

Question 12

Convert 34 (base 10) to binary?

Answer 12

0010 0010

Question 13

Convert 115 (base 10) to binary

Answer 13

0111 0011

Question 14

What is 1 + 1 in Binary?

Answer 14

10 (binary)

Question 15

1101 + 1011 (binary)

Answer 15

1  1  0  1
    1  0  1  1
-----------
1  1  0  0  0
-----------
    1  1  1   1

=11000

Question 16

What is an overflow error?

Answer 16

When the result of binary addition is too big to fit the available space

Question 17

Why do programmers use hexadecimal numbers?

Answer 17

Easier to recognise and remember than large binary numbers.

Question 18

What is 27 (hexadecimal) in denary?

Answer 18

39 (base 10)

Question 19

What is BD (hexadecimal) in denary?

Answer 19

B = 11
D = 13

11*16 = 176
13*1 = 13

176+13 = 189

= 189

Question 20

What is 197 (base 10) in hexadecimal?

Answer 20

197 / 16 = 12
(remainder of 5)

12 / 16 = 0
(remainder of 12)

12 (den) = C (hex)
5 (den) = 5 (hex)

= C5

Question 21

Convert 10100011 to hexadecimal

Answer 21

1010 = 10 (base 10)
0011 = 3 (base 10)

10 = A (hex)
3 = 3 (hex)

= A3

Question 22

Convert C5 (hex) to binary

Answer 22

C = 12 (base 10)
5 = 5 (base 10)

12 = 1100
5 = 0101

= 1100 0101

Question 23

How are characters represented on a computer?

Answer 23

By a binary code

Question 24

What determines the number of characters or symbols that can be used?

Answer 24

The number of bits

Question 25

*ASCII Example* | A is

Answer 25

1000001

Question 26

How are images stored on a computer?

Answer 26

Using binary

Question 27

What is metadata?

Answer 27

Data about the data | E.g. Data to tell the computer how to properly interpret the binary data of the image file to display it (resolution)

Question 28

What is the height and width of an image measured in?

Answer 28

Pixels

Question 29

What is a pixel?

Answer 29

One "dot" in an image

Question 30

What determines the number of bits required to code for one pixel?

Answer 30

How many colours each pixel can represent

Question 31

What is colour depth measured in?

Answer 31

bpp (bits per pixel)

Question 32

Define resolution

Answer 32

The number of pixels per unit | Eg dots per inch (dpi)

Question 33

The greater the resolution, the _____ the file size.

Answer 33

Larger

Question 34

What happens if a bit mapped image is enlarged?

Answer 34

Pixelated or blocky

Question 35

How is an analogue sound converted into digital?

Answer 35

Sampling

Question 36

What is a sample interval?

Answer 36

The time between each sample.

Question 37

The greater the sample interval the _____ the sample rate

Answer 37

Lower

Question 38

What happens when a sound is sampled at a low rate?

Answer 38

- Few samples are taken. - There is a poor match between the original and the sampled sound. - A small file size is required.

Question 39

What happens when sound is sampled at a higher rate?

Answer 39

- More samples are taken - There is a good match between the original and sampled sound - A large file size is required

Question 40

Define bit rate

Answer 40

The amount of space used for each sample

Question 41

A high bit rate means

Answer 41

- More accurate sampling at each point which gives a better quality - More data needs to be stored so there will be a larger file size

Question 42

What process does the CPU do with instructions?

Answer 42

Fetch, decode, execute

Question 43

What is a computer instruction split up into?

Answer 43

Operator and operand

Question 44

What does an operator represent?

Answer 44

An operation to do to the operand

Question 45

What does an operand represent?

Answer 45

The data that the instruction uses

Question 46

What is the operator and operand for: | 10011011

Answer 46

1001 1011 | Operator Operand

Question 47

What is an accumulator?

Answer 47

A register in the CPU used to store the results of an calculation