Term Test

Question 1

Transverse waves particle movement:

Answer 1

Particles move in a perpendicular direction to the energy transfer

Question 2

Longitudinal wave particle movement:

Answer 2

Particles move in a parallel direction to the energy transfer

Question 3

Rarefaction

Answer 3

Particles spread apart in a wave

Question 4

Compression

Answer 4

Particles close together in a wave

Question 5

Wavelength

Answer 5

Distance from crest to crest

Question 6

Amplitude

Answer 6

Max disturbance above rest point

Question 7

Frequency

Answer 7

Number of waves per second

Question 8

Time period

Answer 8

Time for 1 complete wave to pass a point

Question 9

Two uses of ultrasound waves:

Answer 9

Cleaning watches and breaking up kidney stones

Question 10

What is the human hearing range of frequencies of sound?

Answer 10

20hz-20000hz

Question 11

Why can’t sound waves travel through a vacuum?

Answer 11

Because there are no particles for vibrations to take place.

Question 12

How is ultrasound used in foetal scanning?

Answer 12

The transducer converts the sound waves into an electronic image on a computer screen.

Question 13

How is an X-ray photograph taken?

Answer 13

Special machine emits (puts out) a small amount of ionising radiation. This radiation passes through your body and is captured on a special device to produce the image.

Question 14

Which is safer, X-rays or ultrasound?

Answer 14

Ultrasound because it does not use ionising radiation which X-rays do so they do not have the same risks.

Question 15

What’s the speed of all electromagnetic waves?

Answer 15

3.0 * 108 meters per second

Question 16

Use and danger of X-rays:

Answer 16

X-ray scans can diagnose possibly life-threatening conditions such as blocked blood vessels, bone cancer, and infections. However, x-rays produce ionizing radiation—a form of radiation that has the potential to harm living tissue.

Question 17

Ultraviolet danger and use:

Answer 17

UV lamps disinfect surfaces without chemicals, which is crucial in many industries. Excessive exposure to ultraviolet radiation is associated with different types of skin cancer, sunburn, accelerated skin aging, as well as cataracts and other eye diseases.

Question 18

Infrared use and danger:

Answer 18

Infrared (IR) light is used by electrical heaters, cookers for cooking food, short-range communications like remote controls, optical fibres, security systems and thermal imaging cameras which detect people in the dark. The heating effect of IR can cause burns to the skin.

Question 19

Use and danger of gamma rays:

Answer 19

Gamma rays can destroy living cells, produce mutations, and cause cancer. They can be used to treat cancer by focusing the deadly rays on cancer cells.

Question 20

Uses and dangers of microwaves:

Answer 20

Microwaves are used for cooking food, communications and for satellite communications. Intense sources of microwaves can be dangerous through internal heating of body cells.

Question 21

Uses and dangers of visible light:

Answer 21

Light allows us to perceive our surroundings using our eyes. If the irradiance exceeds certain levels, light can also be harmful – especially to the eyes.

Question 22

Uses and dangers of radio waves:

Answer 22

Tissue damage to humans when exposed to high levels of RF levels, but radio waves are used for communication such as broadcasting television and radio, communications and satellite transmissions.

Question 23

Wavefront:

Answer 23

A wave front is defined as a surface over which the phase of the wave is constant.

Question 24

Transmit:

Answer 24

Pass through

Question 25

Reflect

Answer 25

Bounce off

Question 26

Absorb

Answer 26

Take in

Question 27

What are two properties which are the same for all electromagnetic waves?

Answer 27

• all transverse
• all can travel through a vacuum

Question 28

Why can excessive exposure to electromagnetic radiation cause damage to the human body?

Answer 28

These EMFs are in the ionizing radiation part of the electromagnetic spectrum and can damage DNA or cells directly.

Question 29

Longest wavelength in electromagnetic waves?

Answer 29

Radio waves