11. Electromagnetic Waves

Question 1

Properties of electromagnetic waves?

Answer 1

1. Transverse waves
2. do not carry electric charges
3. wave speed= (wave length) (frequency)
   4.Waves entering different media speed and wavelength will drop
4. Waves can travel without a medium
5. Electromagnetic waves undergo reflections and rarefactions
6. They transfer energy
7. ionising waves have higher frequency and higher energy

Question 2

Radio waves

Answer 2

1) satellites
2) Radio receiver
3) Radio/Tv/broadcast

Question 3

Microwaves

Answer 3

1) cooking (oven)
2) communication through mobile phones
3) GPS
4) cancer treatment

Question 4

Infrared

Answer 4

1) Keeping warm
2) data transfer
3) Remote controls

Question 5

Visible light

Answer 5

1) Photography
2) Telecommunication
3) Medicine
4) Artificial light for plants

Question 6

Ultraviolet

Answer 6

1) Disinfection
2) Vitamin D production

Question 7

X-ray

Answer 7

1) Security scanning
2) clinic scanning

Question 8

Gamma rays

Answer 8

1) Disinfection
2) radiotherapy (kill cancer cells)

Question 9

Harmful effects of over exposure to radiation

Answer 9

1) Sun burn (too much ultraviolet) leads to higher risk to skin cancer

Question 10

What is the arrangement of electromagnetic waves from highest to lowest frequency?

Answer 10

Radio waves
Microwaves
Infrared
Visible light
Ultraviolet
X-rays
Gamma rays