P3

Question 1

Electromagnetic spectrum

Answer 1

Radio
Microwaves
Infra red
Visible light
Ultra violet
X rays
Y rays

Question 2

What are radio waves produced by

Answer 2

Electronic oscillators couples to broadcast antennas

Question 3

What are radios used got

Answer 3

Radio and TV broadcasting

Question 4

Microwaves produced by

Answer 4

Aylestone tubes or solid state diodes

Question 5

MicrowVes used for

Answer 5

Domestic ovens

Question 6

Infra red produced by

Answer 6

Light emitting diode

Question 7

Infra red used for

Answer 7

Night vision cameras

Question 8

Visible and ultra violet produced by

Answer 8

Emission by outer electrons transitions

Question 9

Visible light used for

Answer 9

Illumination

Question 10

Ultra violet used for

Answer 10

Insect vision

Question 11

X rays produced by

Answer 11

Inner electron excitation and decay

Question 12

X rays used for

Answer 12

Medical imaging

Question 13

Y rays produced by

Answer 13

Nuclear reactions and particle decays

Question 14

Y rays used for

Answer 14

Radiation steralisation

Question 15

Satellite communications power and mode of transmission

Answer 15

High power over signals over long distance concentrated by dish antennae

Question 16

How are satellite communications used and regulated

Answer 16

Satellite transponders receieve incoming upload signals amplify them and retransmit them as a download signal on a different frequency band

Question 17

Mobile phones power and mod of transmission

Answer 17

High power networked system range several km

Question 18

Mobile phones used and regulated

Answer 18

5 or 10 mhz bands allocated to different operators. 2g 3g 4g cellular networks offering increasing speeds for data. Higher frequencies have greater data capacity but travel less distance through air and penetrate into building less asw

Question 19

Bluetooth power and mode of transmission

Answer 19

Low power device to device links range up to about 10m

Question 20

Bluetooth and WiFi how is it regulated

Answer 20

Both uses the same channel for an extended period of time. Modern Bluetooth uses frequency hopping I.e broadcasting in short bursts on a number of different frequency channels across the band. This reduces the amount of data lost, and in most cases both can maintain the service

Question 21

WiFi power and mode of transmission

Answer 21

Medium power networked system range 10 to 100m

Question 22

Infrared power and mode of transmission

Answer 22

Low power device fo device links range only a few metres

Question 23

Infrared used and regulated

Answer 23

Used for remote controls and for data transfer between computers and phones. The longer the wavelength band is better because irndoes not suffer from sunlight blinding. Atmospheric moisture blocks that range in sunlight

Question 24

Analogue signal

Answer 24

Continuously variable
Signal can have any value

Question 25

Digital signal

Answer 25

Two values only/on or off/0 and 1

Question 26

Advantages of digital signal

Answer 26

Signal can be generated So it cab travel further distances

Question 27

Advantage of digital signal

Answer 27

Signal can carry more info in the same time

Question 28

What wave can be polarised visible light or sound wave

Answer 28

Light wave

Question 29

Strengths of infrared

Answer 29

Does not int3rfer with other devices As frequency is higher than blue tooth Better quality and clearer communication between devices due to higher frequency

Question 30

Weakness of infrared

Answer 30

Works with one device at a time Will only work over short distances because infrared is absorbed scattered by the air

Question 31

Strengths of bluetooth

Answer 31

Does not need to be in direct line of sight works through walls Can be used from a mobile device

Question 32

Weakness of bluetooth

Answer 32

Low bandwidth because of frequency of transmission

Question 33

Advantages of infrared radiation

Answer 33

High frequency so can send large amount of data to receiver

Question 34

Disadvantages of infrared radiation

Answer 34

Easily blocked by obstacles Beavuse line of sight needed

Question 35

Advantages of radio waves

Answer 35

Method of communicating foes not require wires to transmit info

Question 36

Disadvantages of radio waves

Answer 36

Lack fo security Can meddle with different senders

Question 37

Advantages of microwaves

Answer 37

They do not burn food Convenient to use

Question 38

Disadvantages to microwaves

Answer 38

High installario costs Require a lot of space

Question 39

Advantages of infra red

Answer 39

Longer wavelengths than visible light Low maintenance

Question 40

Visible light advantages

Answer 40

High speed transmission

Question 41

Visible light disadvantages

Answer 41

Can be harmful

Question 42

Advantages and disadvantages of ultraviolet

Answer 42

Exposure is a good source of vitamin d Too much can lead to skin cancer

Question 43

X rays advantages and disadvantages

Answer 43

Can diagnose conditions but High radiation levels can make people sick

Question 44

Gamma rays advantages and disadvantage

Answer 44

Strong penetrative But Poor quality radiographs