Data Transmission and Data representation

Question 1

Serial Transmission

Answer 1

Uses a single wire to tranfer the data bits

Question 2

Parallel data transmission

Answer 2

Uses severaral wires to transfer data bits simultaneosly

Question 3

Which transmission is more expensive? Why?

Answer 3

Parallel data transmission. Uses multiple wires

Question 4

Which transmission is used over long distances?

Answer 4

Serial transmission

Question 5

Which transmission is quicker?

Answer 5

Parallel transmission

Question 6

Which transmission has more errors? Why?

Answer 6

Parallel as bits are sent simultaneosly ans errors can occur

Question 7

Simplex transmission

Answer 7

Sending data in one direction only

Question 8

Duplex transmission

Answer 8

Sending data in both directions at the same time

Question 9

Half-Duplex transmission

Answer 9

sending data in both directions, but only one at a time

Question 10

Checksum

Answer 10

Certain calculation happen to the bits and then the check digit is send. The reciever does the same operations and compares them to the check digit

Question 11

Parity check

Answer 11

The last bit is used for the check. The sum of all bits should be even

Question 12

Check digits

Answer 12

A calculation is performed and the check digit is added to the end of the code. The computer will perform the same calculations and compare to the check digits

Question 13

Automatic repeat request

Answer 13

If the reciever detects the data it asks to resend the package. Untill the package is error free, or a limit has been reached.

Question 14

Register

Answer 14

A small piece of memory where values can be held

Question 15

Character

Answer 15

text, numbers and symbols, for example each key on a keyboard

Question 16

Algorithm

Answer 16

a step-by-step set of instructions

Question 17

How does compression work?

Answer 17

Making a file smaller using compression algorithms

Question 18

List 2 types of compression

Answer 18

1) Lossy compression

2) Lossless compression

Question 19

Lossy compression

Answer 19

Data, which is unnecessary is completely and permanently removed

Question 20

Lossless compression

Answer 20

No loss, compression can be reversed and reconstructed, the file will be exactly as it was

Question 21

Where can lossy compression be used? (3)

Answer 21

1) Images
2) Audio
3) Video

Question 22

Where can lossless compression be used (3)

Answer 22

1) Music
2) ZIP
3) Text

Question 23

What does lossy compression remove?

Answer 23

Background noises - not useful, but takes space

Question 24

What does lossless compression remove?

Answer 24

Repeated patterns from a file. It would store the pattern once and where and how many times it is repeated

Question 25

List two ways of storing text

Answer 25

1) .doc

2) .pdf

Question 26

List two ways of storing data

Answer 26

1) .csv

2) .xls

Question 27

List two ways of storing audio

Answer 27

1) .mp3

2) .mid

Question 28

List two ways of storing video

Answer 28

1) .mp4

2) .flv

Question 29

List two ways of storing images

Answer 29

1) .jpg

2) .gif

Question 30

Binary

Answer 30

A system of numbers with a base of 2. Each unit used increases by the power of 2

Question 31

Debug

Answer 31

Finding and fixing problems and errors in a program

Question 32

Bit

Answer 32

Short for binary digit, it is the smallest unit of data in a computer

Question 33

Interference

Answer 33

Disturbances that can occur in the signals when sending data that may corrupt it

Question 34

Where is checksum used?

Answer 34

To detect human errors in ISBN’s, barcodes