Unit 6 - Waves

Question 1

What are the two types of waves?

Answer 1

1. Transverse
2. Longitudinal

Question 2

What is a transverse wave?

Answer 2

A wave for which the oscillations are
perpendicular to the direction of energy
transfer.

Question 3

What is a longitudinal wave?

Answer 3

A wave for which the oscillations are
parallel to the direction of energy
transfer

Question 4

Give two examples of transverse waves.

Answer 4

1. Electromagnetic waves
2. Seismic s-waves

Question 5

Give two examples of longitudinal
waves.

Answer 5

1. Sound waves
2. Seismic p-waves

Question 6

What are the two parts of a longitudinal
wave called?

Answer 6

Compressions and rarefactions.

Question 7

What is a wave’s amplitude?

Answer 7

The maximum displacement of a point
on a wave from its undisturbed position.

Question 8

What is wavelength?

Answer 8

● The distance from a point on a wave to
the same position on the adjacent
wave
● Most commonly peak to peak or
trough to trough

Question 9

What is the frequency of a wave?

Answer 9

The number of waves that pass a given
point each second.

Question 10

What is the unit used for frequency?

Answer 10

Hertz, Hz

Question 11

What is meant by a frequency of 200Hz?

Answer 11

200 waves pass a given point each
second.

Question 12

What is wave speed?

Answer 12

The speed at which the wave moves or
at which energy is transferred through a
medium.

Question 13

What does a wave transfer?

Answer 13

Energy

Question 14

State the equation used to calculate
wave speed. Give appropriate units.

Answer 14

Wave Speed = Frequency x Wavelength
Speed (m/s), Frequency (Hz),
Wavelength (m)

Question 15

What word is used to describe when a
wave bounces off a surface?

Answer 15

Reflection

Question 16

How do sound waves travel through a
solid?

Answer 16

The particles in the solid vibrate and
transfer kinetic energy through the
material.

Question 17

What is the frequency range of human
hearing?

Answer 17

20 Hz - 20kHz
(1kHz = 1000 Hz)

Question 18

What are ultrasound waves?

Answer 18

Waves which have a frequency higher
than the upper limit of human hearing
(20kHz).

Question 19

What natural event causes seismic
waves to be produced? What types are
produced?

Answer 19

● Earthquakes
● They produce both P-waves and
S-waves

Question 20

State a difference between the mediums
that P-waves and S-waves can travel
through.

Answer 20

● P-waves travel through both solids and
liquids
● S-waves only travel through solids
(not liquids)

Question 21

What technique is used to detect objects
in deep water and measure water depth?

Answer 21

● Echo sounding
● High frequency sound waves are emitted,
reflected and detected
● Time difference between emission and detection,
alongside wave speed, are used to calculate
distances

Question 22

What type of spectrum do
electromagnetic waves form?

Answer 22

A continuous spectrum.

Question 23

Order the types of electromagnetic
radiation from lowest to highest
frequency.

Answer 23

● Radio waves
● Microwaves
● Infrared
● Visible Light
● Ultraviolet
● X-rays
● Gamma Rays

Question 24

How do the speeds of EM radiation differ
in a vacuum and in air?

Answer 24

Electromagnetic waves all travel at the
same speed in a vacuum and in air.

Question 25

What property of waves in different mediums causes refraction?

Answer 25

● Velocity ● Wave speed is slower in denser materials, causing refraction

Question 26

In which direction (relative to the normal) do waves refract when entering a denser medium?

Answer 26

● They bend towards the normal ● The angle of refraction is less than the angle of incidence

Question 27

What type of waves can be produced by oscillations in an electrical circuit?

Answer 27

Radio waves.

Question 28

How can radio waves create an alternating current in a circuit?

Answer 28

When radio waves are absorbed, they can induce oscillations in a circuit with the same frequency as the waves themselves.

Question 29

Where do gamma rays originate from?

Answer 29

They originate from changes in the nuclei of atoms.

Question 30

What health effects can ultraviolet waves cause?

Answer 30

● They can cause the skin to age prematurely ● The can increase the risk of developing skin cancer

Question 31

Give three practical uses for infrared radiation

Answer 31

1. Electrical heaters 2. Cooking food 3. Infrared cameras

Question 32

What health effects can X-rays and Gamma rays cause?

Answer 32

● They are ionising radiation so can cause mutations in genes ● They can lead to increased risk of developing various cancers

Question 33

Give two practical uses for microwave radiation.

Answer 33

1. Satellite communications 2. Cooking food

Question 34

Give two practical uses for radio waves.

Answer 34

1. Television transmission 2. Radio transmission