04 Waves Basics 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 time period?

Answer 15

seconds or s

Question 16

What is the unit for amplitude?

Answer 16

metres (m) or decibels(dB)

Question 17

What has a larger wavelength?

Infrared or gamma?

Answer 17

Infrared

Question 18

Match the following terms with their definition

Answer 18

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 19

Why are UV waves dangerous?

Answer 19

They can damage the retina and damage eye sight

They can cause skin cancer

Question 20

What is the use of microwaves?

Answer 20

produced by microwaves to cook food

produced by mobile phones to communicate

Produced by satellites to send signals to satellite dishes

Question 21

What is a transverse wave?

Answer 21

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

Question 22

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

Answer 22

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 23

What are the uses of infrared radiation (IR)

Answer 23

emitted by ovens to cook food

emitted by radiators to heat houses

emitted by tv controllers to control t.v.

Question 24

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

Answer 24

As wavelength increases, frequency decreases

They are inversely proportional

Question 25

What is the use of X-rays?

Answer 25

Used to detect breaks in bones used to detect crystal structure in salts

Question 26

List the EM spectrum in order of increasing frequency

Answer 26

Radio Microwave IR Visible UV X-ray Gamma

Question 27

What is 13 kHz in Hz?

Answer 27

13 x 10³ Hz

Question 28

What is the relationship between time period and frequency?

Answer 28

time period = 1 / frequency or frequency = 1 / time period

Question 29

List the EM spectrum in order of decreasing wavelength

Answer 29

Radio Microwave IR Visible UV X-ray Gamma

Question 30

How is gamma radiation dangerous?

Answer 30

It can cause mutations in cells- cancer

Question 31

How are X-rays dangerous?

Answer 31

They can cause mutations of cells- cancer

Question 32

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

Answer 32

UV X-ray Gamma

Question 33

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

Answer 33

Question 34

How is infrared dangerous?

Answer 34

It can cause skin burns if too hot

Question 35

What is a longitudinal wave?

Answer 35

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

Question 36

Give three examples of a longitudinal wave

Answer 36

sound shock wave P wave

Question 37

What are the uses of radio waves?

Answer 37

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

Question 38

What are the uses of gamma radiation?

Answer 38

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

Question 39

How do you calculate the frequency of a water wave?

Answer 39

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

Question 40

What does monochromatic mean?

Answer 40

Light of a single wavelength or colour.

Question 41

What is 100 MHz in Hz?

Answer 41

100 x 10⁶ Hz

Question 42

What is the unit for wavelength?

Answer 42

metre or m

Question 43

Give three examples of a transverse wave

Answer 43

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

Question 44

List the EM spectrum in order of increasing wavelength

Answer 44

Gamma X-ray UV Visible IR Microwave Radio

Question 45

Which wave has the highest frequency?

Answer 45

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

Question 46

How are all the EM radiation different?

Answer 46

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

Question 47

What is the unit for wavespeed?

Answer 47

metre per second or m/s

Question 48

What is the use of visible light?

Answer 48

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

Question 49

What is the unit for frequency?

Answer 49

Hertz or Hz

Question 50

What type of wave is sound?

Answer 50

Longitudinal vibrations are parallel to direction of wave travel