Waves and EM Spectrum

Question 1

What is the use of UV radiation?

Answer 1

produced by tanning bed lights to tan skin

used to detect conterfeit money

Question 2

Give three properties (features) common to all EM waves

Answer 2

They all…

travel at the speed of light

all transverse waves

all transfer energy and information without transferring matter

all travel through a vacuum

Question 3

Which wave has the largest wavelength?

Answer 3

wave 1

largest distance between adjacent crests

Question 4

How can you make a transverse wave with a slinky?

Answer 4

Move your hand in a side to side movement

Question 5

List the EM spectrum in order of decreasing frequency

Answer 5

Gamma

X-ray

UV

Visible

IR

Microwave

Radio

Question 6

How is wavespeed, wavelength and frequency related?

Answer 6

wavespeed = wavelength x frequency

Question 7

Label the compressions, rarefactions and wavelength on the longitudinal wave below

Answer 7

Question 8

What is 204 nm in m?

Answer 8

204 x 10^-9 m

Question 9

How can you make a longitudinal wave with a slinky?

Answer 9

move your hand in a forwards and backwards movement

Question 10

How would you measure the frequency of waves passing a jetty?

Answer 10

Time how long it take for 10 waves to pass the end of the jetty

frequency = 10 waves / time for 10 waves to pass

Question 11

Fred noticed that 10 waves passed a point in 5 seconds. What is the frequency of the wave?

Answer 11

frequency = 10 waves/ 5 s

= 2 Hz

Question 12

What is 700 micrometres in metres?

Answer 12

700 x 10^-6 m

Question 13

Fred noticed that 10 waves passed a point in 5 seconds. What is the period of the wave?

Answer 13

Time period = 5 seconds / 10 waves

= 0.5 seconds for one wave to pass

Question 14

Which wave has the largest amplitude?

Answer 14

wave 2

It has the largest displacement from the equilibrium

Question 15

What is the unit for amplitude?

Answer 15

metres (m) or decibels(dB)

Question 16

What has a larger wavelength?

Infrared or gamma?

Answer 16

Infrared

Question 17

Match the following terms with their definition

Answer 17

frequency- the number of waves going past in one second

wavelength- the length of one repeat of the wave pattern

wave speed- how far a wave travels in one second

Question 18

Why are UV waves dangerous?

Answer 18

They can damage the retina and damage eye sight

They can cause skin cancer

Question 19

What is the use of microwaves?

Answer 19

produced by microwaves to cook food

produced by mobile phones to communicate

Produced by satellites to send signals to satellite dishes

Question 20

What is a transverse wave?

Answer 20

Where the oscillation is 90° to the direction of wave travel

Question 21

How do the waves of red light differ from waves of violet light

Answer 21

ROY G BIV

Red light-larger wavelength and lower frequency- it has less energy

Blue light- smaller wavlength and higher frequency- it has more energy

Question 22

What are the uses of infrared radiation (IR)

Answer 22

emitted by ovens to cook food

emitted by radiators to heat houses

emitted by tv controllers to control t.v.

Question 23

What is the relationship between wavelength and frequency of a wave?

Answer 23

As wavelength increases, frequency decreases

They are inversely proportional

Question 24

What is the use of X-rays?

Answer 24

Used to detect breaks in bones

used to detect crystal structure in salts

Question 25

List the EM spectrum in order of increasing frequency

Answer 25

Radio Microwave IR Visible UV X-ray Gamma

Question 26

What is 13 kHz in Hz?

Answer 26

13 x 10³ Hz

Question 27

List the EM spectrum in order of decreasing wavelength

Answer 27

Radio Microwave IR Visible UV X-ray Gamma

Question 28

How is gamma radiation dangerous?

Answer 28

It can cause mutations in cells- cancer

Question 29

How are X-rays dangerous?

Answer 29

They can cause mutations of cells- cancer

Question 30

Which parts of the EM spectrum is considered to be dangerous?

Answer 30

UV X-ray Gamma

Question 31

Label the wavelength, amplitude, crest and trough of the transverse wave below

Answer 31

Question 32

How is infrared dangerous?

Answer 32

It can cause skin burns if too hot

Question 33

What is a longitudinal wave?

Answer 33

Where the oscillation is along OR parallel to the direction of wave travel.

Question 34

Give three examples of a longitudinal wave

Answer 34

sound shock wave P wave

Question 35

What are the uses of radio waves?

Answer 35

radio signal for radio radar walkie talkie signals t.v. signals

Question 36

What are the uses of gamma radiation?

Answer 36

Used to kill cancer tumours used to sterilise medical equipment emitted by radioisotope tracers to detect cancer in the body

Question 37

How do you calculate the frequency of a water wave?

Answer 37

frequency = number of waves/ time for those waves to pass a point

Question 38

What does monochromatic mean?

Answer 38

Light of a single wavelength or colour.

Question 39

What is 100 MHz in Hz?

Answer 39

100 x 10⁶ Hz

Question 40

What is the unit for wavelength?

Answer 40

metre or m

Question 41

Give three examples of a transverse wave

Answer 41

water wave radio, microwave, IR, UV, X ray, Gamma Seismic S wave

Question 42

List the EM spectrum in order of increasing wavelength

Answer 42

Gamma X-ray UV Visible IR Microwave Radio

Question 43

Which wave has the highest frequency?

Answer 43

wave 3 ## Footnote *it has more waves per second*

Question 44

How are all the EM radiation different?

Answer 44

They have.... different wavelengths different frequencies therefore they have different uses and dangers

Question 45

What is the unit for wavespeed?

Answer 45

metre per second or m/s

Question 46

What is the use of visible light?

Answer 46

produced by light bulbs to see things produced by bioluminescent creature to attract prey

Question 47

What is the unit for frequency?

Answer 47

Hertz or Hz

Question 48

How is sound created?

Answer 48

sound is created by vibrations

Question 49

List some properties of sound

Answer 49

1. it is a longitudinal wave 2. it is created by a vibration 3. it cannot travel through a vacuum 4. it can travel through a solid, liquid or gas 5. it can have different frequencies or pitch 6. it can be reflected and diffracted

Question 50

What type of wave is sound?

Answer 50

Longitudinal vibrations are parallel to direction of wave travel