Analogue and digital communication

Question 1

What is analogue?

Answer 1

Describes a signal that can have an unlimited number of values

Question 2

What is digital?

Answer 2

Describes a signal that can have only two values: on or off

Question 3

Value of digital signals

Answer 3

Two values
1 is on
0 is off

Question 4

Value of analogue signals

Answer 4

Constantly changing

Question 5

Examples of use of digital signals

Answer 5

TV remote
sends a digital signal to your TV when you change channel. Inside the remote there is a small infrared light, this rapidly flashes on and off.

Question 6

Advantages of digital signals

Answer 6

• Any interference affecting the signal can easy be removed
• Clear to see state of signal (1 or 0)
• Many different signals can be sent at once, using multiplexing. So more info given at one time

Question 7

What is DAB radio?

Answer 7

Digital audio broadcasting

Question 8

Advantages of DAB radio

Answer 8

More stations available

Less chance of interference

Question 9

Disadvantages of DAB radio

Answer 9

Not all areas of UK are covered

Sometimes poor sound quality (due to compressed sound)

Question 10

What is multiplexing?

Answer 10

A technique used to transmit several digital signals at once

Question 11

Uses for infrared

Answer 11

TV remotes
Sending data to and from laptops and phones
Sensors- burglar alarms and security lighting