Physics - Waves

Question 1

What is a transverse wave?

Answer 1

The vibrations of the waves are perpendicular to the direction of energy transfer

Question 2

What is a longitudinal wave?

Answer 2

The vibrations of the waves are parallel to the direction of energy transfer

Question 3

Define amplitude

Answer 3

the maximum displacement of a point on a wave away from its undisturbed position

Question 4

Define wavelength

Answer 4

the distance from a point on one wave to the equivalent point on the adjacent wave

Question 5

What is equation linking time period and frequency?

Answer 5

Time period = 1 ÷ frequency

Question 6

What are the units for frequency?

Answer 6

Hz or Hertz

Question 7

What is equation linking wave speed, frequency and wavelength?

Answer 7

wave speed = frequency × wavelength

Question 8

Are electromagnetic waves transverse or longitudinal?

Answer 8

Transverse

Question 9

What do EM waves transfer?

Answer 9

Energy

Question 10

Explain why EM waves are not mechanical waves.

Answer 10

They can travel through a vacuum

Question 11

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

Answer 11

Gamma, X-Rays, Ultraviolet, Visible light, Infra-red, Microwave, Radio waves

Question 12

What can occur when a EM wave meets a substance?

Answer 12

absorbed, transmitted, refracted or reflected

Question 13

Why does refraction happen?

Answer 13

a change in velocity

Question 14

How can EM waves be produced?

Answer 14

Changes inside an atom

Question 15

How can radio waves be produced?

Answer 15

Oscillations in an electrical circuit

Question 16

How can we detect radio waves?

Answer 16

they create an alternating current with the same frequency

Question 17

What is Radiation dose

Answer 17

a measure of the risk of harm resulting from an exposure of the body to the radiation.

Question 18

Which EM waves are ionising?

Answer 18

X-rays and Gamma

Question 19

What are the dangers of ultraviolet waves?

Answer 19

can cause skin to age prematurely and increase the risk of skin cancer

Question 20

What are the dangers of X-rays and Gamma rays?

Answer 20

can cause the mutation of genes and cancer

Question 21

What can radio-waves be used for?

Answer 21

television and radio

Question 22

What can microwaves be used for?

Answer 22

satellite communications, cooking food

Question 23

What can infrared be used for?

Answer 23

electrical heaters, cooking food, infrared cameras

Question 24

What can visible light be used for?

Answer 24

fibre optic communications

Question 25

What can ultraviolet be used for?

Answer 25

energy efficient lamps, sun tanning

Question 26

What can gamma rays be used for?

Answer 26

Sterilising equipment, medical treatment

Question 27

What can x-rays be used for?

Answer 27

medical imaging and treatments

Question 28

Why are X-rays used for medical imaging?

Answer 28

they pass through flesh but not bone

Question 29

Why are gamma rays used for treating cancer and sterilising medical equipment?

Answer 29

high doses kills cells and bacteria

Question 30

Which surfaces absorb radiation?

Answer 30

all surfaces, black is the best absorber

Question 31

Which surfaces emit radiation?

Answer 31

all surfaces, black is the best emitter