Using Waves

Question 0

Radio waves

Answer 0

Sources - radio transmitters
Detectors - radios TV aerials
Uses - fm radio and TV signals

Question 1

The electromagnetic spectrum

Answer 1

Radio waves
Microwaves
Infra red
Visible light
Ultraviolet
X-rays 
Gamma rays

Question 2

Properties of EM waves

Answer 2

• transfer energy
• transverse waves
• travel at the speed of light in a vacuum
• can be reflected, refracted and diffracted

Question 3

Microwaves

Answer 3

Sources - microwave transmitters and ovens
Detectors - microwave receivers
Uses - mobile communication, cooking

Question 4

Infra red

Answer 4

Sources - anything hot
Detectors - skin, blackened thermometer
Uses - night vision, tv remotes and inferred cookers

Question 5

Visible light

Answer 5

Sources - luminous objects
Detectors - the eye, photographic film
Uses - seeing communication photography

Question 6

Ultraviolet

Answer 6

Sources - UV lamps and the sun
Detectors - skin photographic film and some fluorescent chemicals
Uses - fluorescent tunes and UV tanning lamps

Question 7

X-rays

Answer 7

Sources - X-ray tubes
Detectors - photographic film
Uses - internal observation

Question 8

Gamma rays

Answer 8

Sources - radioactive materials
Detectors - Geiger-muller tube
Uses - sterilising equipment and food, radiotherapy

Question 9

Dangers of electromagnetic waves

Answer 9

Radio waves - 
Microwaves - burning of tissue
Infra red - skin burns 
Visible light - damage the eyes
Ultraviolet lift - damage to skin and eyes
X-rays - can cause cancer
Gamma rays - can cause mutations

Question 10

Digital signals

Answer 10

Information is converted to a binary code
Regeneration of digital signals creates a clean, accurate copy of the signal
Easier to design

Question 11

Analogue signals

Answer 11

Imitation is converted to electrical voltages or varying currents