Waves and the Electromagnetic Spectrum Flashcards Preview

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Flashcards in Waves and the Electromagnetic Spectrum Deck (36)
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1
Q

What is the frequency of a wave?

A

The number of complete cycles of a wave passing a certain point.

2
Q

True of false? Transverse waves have sideways vibrations?

A

True

3
Q

Give 2 examples of longitudinal waves.

A

Sound waves and P-waves

4
Q

Calculate the frequency of a wave travelling at 2m/s with a wavelength of 3.5x10^-12

A

5.71428571x10^11

5
Q

Give 3 ways you can measure the speed of waves.

A

1) Using an oscilloscope
2) Water ripples and a strobe light.
3) Using a metal rod, hammer and a microphone connected to a computer

6
Q

Briefly describe refraction.

A

Waves Changing Direction at a Boundary

7
Q

Does the frequency of the wave change at all during refraction?

A

No.

8
Q

How do sound waves pass on energy?

A

Through rarefactions and compressions transferring energy through particles.

9
Q

What is the frequency of ultrasound?

A

Higher than 20,000Hz

10
Q

Give 2 uses of ultrasound.

A

Medical imaging and Industrial imaging.

11
Q

What is the frequency of infrasound?

A

Below 20Hz

12
Q

Give 2 animals that use infrasound for communication.

A

Elephants and whales

13
Q

Give 2 things that cause seismic waves.

A

Earthquakes and Explosions

14
Q

Can P-waves travel through the earth’s core?

A

Yes, S-waves can’t

15
Q

Describe P-waves

A

Longitudinal
They travel through solids and liquids
They travel faster than s-waves

16
Q

Describe S-waves

A

Transverse
Can only travel through solids
Slower the P-waves

17
Q

Complete:

Angle of incidence=?

A

Angle of reflection

18
Q

What does Total Internal reflection depend on?

A

The critical angle

19
Q

If the light ray enters a block at an angle larger than the critical angle, What happens?

A

No light comes out, it’s all internally reflected

20
Q

If light is reflected by something rough, does the surface look matted or shiny?

A

Matted

21
Q

Why do you need to do the refraction practical in a dim room.

A

So you can clearly see the ray

22
Q

Do different materials refract rays at different angles?

A

Yes, pure glass bends light more than plastic does.

23
Q

If white light travels through a green filter then a blue filter. What colour will the light be?

A

No light travels through.

24
Q

Why are objects different colours?

A

They reflect different wavelengths of light

25
Q

Which lens has a virtual Focus Point?

A

Concave Lens

26
Q

What does the power of a lens increase with?

A

The curvature

27
Q

Give the order of the Electromagnetic Spectrum from highest to lowest frequency.

A

Gamma, X-rays, UV, Visible, Infrared, Microwaves, Radiowaves

28
Q

What do all EM waves do?

A

Transfer energy to their surroundings.

29
Q

Which colour is the best emitter and absorb-er of EM waves?

A

Black

30
Q

Give 2 uses of Radio waves

A

Communication, broadcasting and used by satelites

31
Q

Give 2 uses of microwaves

A

Satellites, microwave ovens

32
Q

Give 2 uses of Infrared

A

Increase or monitor temperature, Thermal imaging, transferring information

33
Q

Give 2 uses of Visible Light

A

Photographs and illuminating things

34
Q

Give 2 uses of UV

A

UV lights, Security pens, Sterilising water.

35
Q

Give 2 uses of X-rays

A

Seeing inside things, airport security scanners

36
Q

Give 2 uses of Gamma rays

A

Sterilisation, tracers, cancer detection and treatment.