EM Waves And Communication

Question 0

In general which waves can pass through materials?

Answer 0

Those at either end of spectrum, and less as it gets to middle as these are absorbed

Question 1

List 7 types of waves, starting with longest

Answer 1

Radio waves
Micro waves
Infra red (heat)
Visible light (sun)
Ultra violet (gives suntan)
X rays
Gamma rays

Question 2

Are longer or shorter waves more dangerous?

Answer 2

Shorter as have more energy

Eg gamma and x rays

Question 3

What is caused when EM radiation is absorbed?

Answer 3

Heating and ionisation (if frequency high enough)

Question 4

Why are light, radio and electrical signals good for communication?

Answer 4

Signals travel really fast

Question 5

What is the advantage and disadvantage of optical fibres and cables?

Answer 5

Information is secure - not tapped into
But….
Difficult to repair

Question 6

What is the advantage and disadvantage of radio / wireless signals

Answer 6

Wireless is portable (mobile phone, laptop, wi-fi)
But ….
Radio / wireless signals can be intercepted, rely on aerials, signal strength can depend on location