Combined Physics - P6 Waves

Question 1

What two types of wave are there?

Answer 1

• Transverse
• Longitudinal

Question 2

Give an example of a longitudinal wave

Answer 2

Sound

Question 3

Describe how longitudinal waves transfer energy.

Answer 3

Vibrations are parallel to energy transfer

Question 4

Give an example of a transverse wave

Answer 4

• All electromagnetic waves
• A ripple on water
• A wave on a string

Question 5

Describe how transverse waves transfer energy.

Answer 5

Vibrations are perpendicular to energy transfer

Question 6

Compare the sound of the two waves in the image in terms of loudness and pitch.

Answer 6

• They have the same loudness.
• Wave B has a higher pitch.

Question 7

Name the properties of the wave labelled a) and b)

Answer 7

a) Wavelength
b) Amplitude

Question 8

Name the two regions of a longitudinal wave labelled ‘C’ and ‘R’.

Answer 8

C = compression

R = rarefaction

Question 9

What equation links wave speed, frequency and wavelength?

Answer 9

Wave speed = frequency x wavelength

V = 𝘧 λ

Question 10

What are X-rays used for?

Answer 10

Medical imaging

Question 11

What EM waves can our eyes detect?

Answer 11

Visible light

Question 12

What are gamma rays used for?

Answer 12

• Killing cancer cells
• Sterilizing medical equipment

Question 13

What does frequency mean?

Answer 13

The number of complete waves passing a certain point in a second (1 Hz is 1 wave per second)

Question 14

What EM waves can have hazardous effects on human body?

Answer 14

Ultraviolet waves, X-rays and gamma rays

Question 15

Which EM wave causes skin cancer?

Answer 15

Ultraviolet waves cause skin cancer

Question 16

Write the electromagnetic spectrum in order from longest to shortest wavelength.

Answer 16

Question 17

Compare the sound of the two waves in the image in terms of loudness and pitch.

Answer 17

• They have the same pitch.
• Wave B is quieter than Wave A.

Question 18

Name the EM wave that communicates with satellites

Answer 18

Microwaves

Question 19

What danger do X-rays and gamma rays pose?

Answer 19

Can cause cancer

Question 20

What are microwaves used for?

Answer 20

• Satellite communications
• Cooking food
• Mobile phone communication

Question 21

What is visible light used for?

Answer 21

1) Communication using fibre optics
2) Anything that you need to see e.g.:

• Charging lights on battery chargers
• Traffic Lights
• Lights on displays such as TV, phone, laptop

Question 22

What are radio waves used for?

Answer 22

Television and radio

Question 23

What are infrared waves used for?

Answer 23

• Electrical heaters
• Cooking food
• Infrared cameras
• TV remotes

Question 24

What is ultraviolet used for?

Answer 24

• Tanning beds
• Detecting forged bank notes

Question 25

What is the dashed line in a refraction diagram called?

Answer 25

Normal

Question 26

What do you call the process whereby light bends as it enters a different medium?

Answer 26

Refraction

Question 27

**Higher Q**. What can oscillations in electrical circuits cause?

Answer 27

Radio waves

Question 28

Why does light bend as it moves from air into glass?

Answer 28

Glass is denser than air, so the light wave slows down.

Question 29

**Higher Q**. How can radio waves themselves induce oscillations in an electrical circuit?

Answer 29

Radio waves can be absorbed, creating an alternating current with the same frequency as the radio wave itself.

Question 30

Describe how you would use a ripple tank to measure the speed of a water wave.

Answer 30

* Set the frequency of the wave on the signal generator. * The dipper will oscillate and generate a wave at the set frequency. * Turn the strobe light on. * Take a picture of the wave fronts that appear on the screen. * Using a ruler, measure the wavelength of one wave (to increase accuracy, measure the length of 10 waves then divide by 10). * Use the equation: v=fλ to calculate the speed of the wave.

Question 31

Describe how you would measure the speed of a wave on the string?

Answer 31

* Set the frequency of the wave on the signal generator. * Using a ruler, measure the wavelength of one wave (to increase accuracy, measure the length of 10 waves then divide by 10). * Use the equation: v=fλ to calculate the speed of the wave.

Question 32

Put the following surfaces in order of the amount of infrared radiation they emit (from most to least). ## Footnote **Shiny Black, Matt Black, Silver, White**

Answer 32

1. Matt black (most) 2. Shiny black 3. White 4. Silver (least)

Question 33

**Higher Q.** Complete the diagram to show waves moving from a less dense to a more dense medium.

Answer 33

Question 34

**Higher Q**. Complete the diagram to show waves moving from a less dense to a more dense medium.

Answer 34

Question 35

Describe how you would investigate the amount of infrared radiation emitted by different surfaces using the equipment below.

Answer 35

* Fill the Leslie’s cube with boiling water and place on a heat proof mat. * Measure 15 cm from the cube using a ruler and place an infrared detector there facing the cube. * Record the amount of infrared it detects. * Repeat for each side of the cube (which has different faces, e.g. silver, black matt, black shiny, white).

Question 36

Describe how the equipment can be used to measure the speed of sound

Answer 36

* Connect a speaker to a signal generator and switch on to a set frequency (this gives your frequency, f) * Connect microphones to the oscilloscope so they each show a wave on the screen. * Place both microphones next to the oscilloscope. * Move one microscope away until the waves on the screen match each other. * Measure the distance between the microphones at this point – this is the wavelength, λ. * Use the equation: v=fλ to calculate the speed of the wave.