6.2

Question 1

What order are the electromagnet waves in decreasing wavelength in metres? (7)

Answer 1

1. Radio
2. Microwave
3. Infrared
4. Visible
5. Ultraviolet
6. X-ray
7. Gamma rays

Question 2

What order are the electromagnet waves in decreasing frequency in metres? (7)

Answer 2

1. Gamma rays
2. X-ray
3. Ultraviolet
4. Visible
5. Infrared
6. Microwave
7. Radio

Question 3

What are the 4 main components about electromagnetic waves? (4)

Answer 3

• Does not require medium (particles) to move.
• All transverse waves
• All have same velocity in space (vacuum)
• Can transfer energy from source to absorber
• (a) Microwave source to food
• (b) Sun emits energy to earth

Question 4

What are the 3 relationships that electromagnetic waves have (3)?

Answer 4

• All EM waves move at constant speed.
• As wavelength increases, frequency decreases.
• As frequency increases, energy of wave increases.

Question 5

What EM waves can we see?

Answer 5

Our retinas can only detect visible light.

Question 6

What happens when a wave enters a denser material? (1)

Answer 6

It bends towards the normal.

Question 7

What happens when a wave enters a less dense material? (1)

Answer 7

It bends away from the normal.

Question 8

What two things can affects the way a material interacts with a wave?

Answer 8

• The wavelength and frequency of the EM wave (e.g. glass will transmit/refract visible light, absorb UV radiation and reflect IR radiation).
• Difference or change in velocity (e.g. light slows down when passing through a denser medium, shorter wavelengths (e.g. blue light) slows down more than longer wavelengths (e.g. red light)).

Question 9

Why does dispersion of white light occur in a prism? (1)

Answer 9

Different wavelengths of light refract a different amount so they spread out creating a rainbow effect.

Question 10

Why do water waves refract when changing medium from deep to shallow water? (1)

Answer 10

The wave’s speed and wavelength decreases in denser materials (travels slower in shallow water so wavelength smaller)

Question 11

What produces radio waves?

Answer 11

Oscillations in electrical circuits

Question 12

How are radio waves received? (4)

Answer 12

1. Radio waves absorbed by receiver antenna
2. It induces oscillations in small current with same frequency as radio waves.
3. Current amplified and converted into sound or data