P1f-data Transmission

Question 1

How does the remote control electrical devices?

Answer 1

Remote control emits pulses IR

Device detects and decodes pattern of pulses coming from remote control and follow coded instruction

Question 2

How do passive infrared sensors and thermal imaging cameras work?

Answer 2

Heat radiation given out by hot objects
Hotter the object more IR given out
Infrared sensors detect body heat

Question 3

What are analogue signals?

Answer 3

Signals that have a continuously variable value

Question 4

What are digital signals?

Answer 4

Signals are either on or off

1 or 0

Question 5

What is interference?

Answer 5

When two or more waves of a similar frequency meet, they can create one combined signal with a new amplitude

Question 6

Why is easier to remove noise from digital signals?

Answer 6

It can only be on or off

1 or 0

Question 7

What is multiplexing?

Answer 7

When you transmit several signals at the same time using just one cable or EM wave

Question 8

What are some everyday uses of infrared radiation?

Answer 8

Remote controls

Short distance data links for computers or mobile phones

Question 9

How do optical fibres transmit data?

Answer 9

They allow rapid transmission of data

They allow the transmission of data pulses using light

Question 10

What are the advantages of using optical fibres?

Answer 10

Allows more information to be transmitted
Multiplexing
Lack of interference in the final signal