Chapter 3 - Data Representation

Question 1

Byte

Answer 1

8 bits

Question 2

Nibble

Answer 2

4 bits

Question 3

Kilobyte

Answer 3

1024 bytes

Question 4

Megabyte

Answer 4

1024 kilobyte

Question 5

Gigabyte

Answer 5

1024 megabyte

Question 6

Terabyte

Answer 6

1024 gigabytes

Question 7

Binary

Answer 7

Base 2 number system used by computers uses the digits 1 and 0 only

Question 8

Denary

Answer 8

Base 10 number system how we normally count uses digits 0 and 9

Question 9

Hexadecimal

Answer 9

Base 16 number system used by humans to represent groups of four bits at a time. Uses digits 0 to 9 and A to F

Question 10

Character set

Answer 10

The set of symbols that can be represented by a computer. They can be letters, digits, space, punctuation marks and some control characters such as “escape”. Each character is represented by a numerical code that is stored as a binary integer.

Question 11

ASCII

Answer 11

American standard code for information interchange. A 7 bit character set used by PCs

Question 12

EBCDIC

Answer 12

Extended binary coded decimal interchange code. 8 bit character set used by older mainframes

Question 13

Unicode

Answer 13

A 16 or 32 bit character set that allows many more characters to be coded

Question 14

Bitmap image

Answer 14

An image that has been stored as a series of values per pixel. The colour of each individual pixels is stored in a file

Question 15

Pixel

Answer 15

Short for picture element. It is the smallest component of a bitmapped image

Question 16

Colour depth

Answer 16

The number of bits used to represent the colour of a single pixel in a bitmapped image. Higher colour depth gives a broader range of distinct colours.

Question 17

Resolution

Answer 17

The number of pixels in an image

Question 18

Metadata

Answer 18

Data about data. In the case of image files metadata is the data the computer needs to interpret the image data in the file

Question 19

Analogue

Answer 19

A continuously changing wave such as natural sound

Question 20

Digital

Answer 20

Data that is made up of separate values. How data is stored on a computer

Question 21

Sample rate

Answer 21

The number of times per second that the sound wave is measured. The higher the rate the more accurately the sound wave is represented.

Question 22

Sample interval

Answer 22

The time gap between measurements of sound wave being taken. Another way of expressing the sample rate

Question 23

Sample resolution

Answer 23

The number of bits used to store the values of each sample. The greater the number of bits the more accurately the value is stored

Question 24

ADC

Answer 24

Analogue and digital converter takes real world analogue data and converts it to a binary representation that can be stored on a computer

Question 25

Data

Answer 25

Facts and figures with no context or format to give them meaning. Coded information

Question 26

Information

Answer 26

Processed data that had context and format so that it conveys meaning

Question 27

Bit

Answer 27

A single binary digit 1 or 0