Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A Level Physics > Waves > Flashcards

Waves Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Described transverse wave.

A

A type of wave in which the particles oscillate perpendicular to the direction the wave travels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Examples of transverse waves.

A

EM waves, water and s-waves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe a longitudinal wave.

A

A type of wave in which the particles oscillate parallel to the direction of wave travel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Examples of longitudinal waves.

A

Sound waves and p-waves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the wavelength of a wave?

A

It is the distance between two matching points on neighbouring waves, measured in metres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the amplitude of a wave?

A

Amplitude is the maximum displacement of a point from the centre of oscillation, measured in metres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The larger the amplitude the greater the what of the wave?

A

The greater the energy of the wave.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The period of a wave, T, is what?

A

The time taken for a point on the wave to move through one complete oscillation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Frequency of a wave is measured in what?

A

Hertz, Hz.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Equation linking time period and frequency of a wave:

A

f=1/T
Where:
f is frequency in Hz.
T is time period in s.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Frequency is a measure of what?

A

Number of waves that pass a point in 1 second.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The wave equation is:

A 
v=fλ
Where:
v is velocity in ms^-1.
f is frequency in Hz.
λ is wavelength in m.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Electromagnetic waves are transverse, true or false?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

True or false, electromagnetic waves travel at different speeds?

A

False, they all travel at the same speed (speed of light).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What speed do electromagnetic waves travel through a vacuum at?

A

3x10^8ms^-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Typical wavelength for a radiowave is what?

A

10^3m to a few metres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Typical wavelength for a microwave is what?

A

10^-2m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Typical wavelength for an infrared wave is what?

A

10^-5m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Typical wavelength of visible light is what?

A

10^-7m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Typical wavelength of ultraviolet light is what?

A

10^-8m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Typical wavelength of X-ray radiation is what?

A

10^-10m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Typical wavelength of a gamma ray is what?

A

10^-12m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

EM radiation travels by what?

A

Oscillations in both the electric and magnetic fields.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Superposition of waves is what?

A

Where the waves are both causing the same particle to oscillate causing the amplitudes to be summed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

If two waves of the same wavelength and amplitude are perfectly in phase, what can be said about the amplitude of the resultant wave?

A

It is twice the amplitude of one of the initial waves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When waves cause a resultant wave with a greater amplitude than the initial waves what kind of interference is this?

A

Constructive interference.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

When two waves have the same amplitude and wavelength but are perfectly out of phase what can be said about the resultant wave?

A

There isn’t one. The oscillations of the waves cancel each other perfectly leaving no wave.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

When two waves cause a resultant wave with less energy than the initial wave what kind of interference is that?

A

Destructive interference.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Waves that are perfectly out of phase have a phase difference of what?

A

π

30
Q

Calculate what 1 rad is in degrees.

A

1 rad = 360/2π = 57.3 degrees

31
Q

Calculate what 1 degree is in radians.

A

1 degree = 2π/360

32
Q

Diffraction is what?

A

The spreading out of a wave as it passes an obstacle or goes through a gap.

33
Q

In order for diffraction to occur what must be said to be true about the size of obstacle/gap and wavelength?

A

The obstacle/gap must be a similar size to the wavelength else the diffraction is negligible.

34
Q

What happens to the energy per length of wavefront as a wavefront is being spread out by diffraction?

A

The energy per length of wavefront decreases.

35
Q

What can be said about the overall energy of the wave as it is diffracted?

A

The overall energy of the wave remains the same (conservation of energy).

36
Q

What happens to the amplitude of the wavefront during diffraction?

A

The amplitude decreases.

37
Q

Huygen constructs work by assuming what?

A

A wavefront can be modelled as a row of oscillating particles that cause wavelets which can be connected to show a wavefront.

38
Q

Diffraction grating equation linking d and N.

A

d=1/N
Where:
d is the distance between the slits, m.
N is the line density, m^-1.

39
Q

What is the diffraction grating formula?

A 
dsinθ=nλ
Where:
d is the distance between the slits, m.
n is the order of the maxima.
λis the wavelength, m.
40
Q

Define refraction.

A

The changing of the direction of a wave as it changes medium.

41
Q

What happens if a wave travels from a less dense into a more dense medium?

A

The wave bends towards the normal.

42
Q

What happens if the wave travels from a more dense into a less dense medium?

A

The wave bends away from the normal.

43
Q

What is a normal?

A

The perpendicular to the surface being studied.

44
Q

Snell’s Law using angles:

A

sini/sinr = n

Or

n1sinθ1 = n2sinθ2

45
Q

Snell’s Law using velocities:

A

v1/v2 = n

46
Q

What is the absolute refractive index of a material?

A

The absolute refractive index for a material is the refractive index of light travelling from a vacuum into a particular substance.

47
Q

Equation for finding the critical angle:

A

sinc = 1/n

Where:
c is critical angle.
n is the absolute refractive index of the material light is travelling out of.

48
Q

What happens when i

A

Refraction occurs.

49
Q

What happens when I=θc?

A

The ray is split part of it is refracted along the very edge of the prism, part is reflected back into the prism.

50
Q

What happens if i>θc?

A

Total internal reflection occurs.

51
Q

Give everyday uses of total internal reflection (excluding optical fibres).

A 
Telescopes (lens).
Medical keyhole cameras.
Diamonds.
Bike reflectors.
Cats eyes on the road.
52
Q

What are the two types of lenses?

A

Convex (converging) and concave (diverging).

53
Q

What happens when you look at a close object (within the focal length) through a convex (converging) lens?

A

The image is:
Magnified
Upright
Virtual

54
Q

What happens if you look at a far object (beyond focal length) through a convex (converging) lens?

A

The image is:
Inverted
Diminished
Real

55
Q

What happens if you look at an object through a concave (diverging) lens?

A

The image is:
Diminished
Upright
Virtual

56
Q

What is the centre of a lens known as?

A

The optical centre.

57
Q

Where is the principle focus on a convex (converging) lens?

A

Where all rays converge (cross).

58
Q

Where is the principle focus on a concave (diverging) lens?

A

When the diverging rays are traced backwards and the they all converge, this is where the principle focus is.

59
Q

What is a node on a stationary wave?

A

A point of minimum displacement.

60
Q

What is an antinode on a stationary wave?

A

A point of maximum displacement.

61
Q

What does the first harmonic look like on a string?

A

The first harmonic on a string is when the wave is stationary and there is a node at each end with one antinode in the middle.

62
Q

What can be said about the wavelength of the wave if the first harmonic is produced in a string?

A

The wavelength will be 2x the length of the string.

63
Q

The fundamental frequency of a wave is the frequency when…

A

…the first harmonic is produced as a standing wave.

64
Q

Wave speed in a string depends on what?

A

Length, tension and material.

65
Q

Stationary waves in strings always start and end in what?

A

Nodes.

66
Q

What can be said about the wavelength of the second harmonic in a string?

A

The wavelength is equal to the length of the string.

67
Q

What can be said about the wavelength of the third harmonic in a string?

A

It is equal to 2/3 length of the string.

68
Q

What can be said about the frequencies of the 2 and 3rd harmonics for a stationary wave in a string?

A

The frequency of the second is 2x the fundamental frequency.

The frequency of the third is 3x the fundamental frequency.

69
Q

What can be said is at the start and end of a stationary wave in a closed pipe?

A

There is always an antinode at the open end (start) and a node at the closed end (end).

70
Q

Can we get all harmonics in a closed pipe?

A

No we can only get odd harmonics, so 1st, 3rd, 5th etc.

71
Q

Can we get all harmonics with an open pipe?

A

No we can only get the even harmonics.

72
Q

What can be said about the start and end of a stationary wave in an open pipe?

A

The wave starts and ends with both antinodes.

A Level Physics (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions