Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

physics content ocr a > waves > Flashcards

waves Flashcards

1
Q

what is a progressive wave?

A

a wave that transfers energy from one point to another without transferring matter

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

define displacement of a wave

A

how far a point on a wave has moved from its equilibrium

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

define amplitude of a wave

A

maximum magnitude of the displacement

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

define wavelength of a wave

A

the distance between neighbouring points on two waves

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

define period of a wave

A

time taken for a whole cycle to complete

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

define frequency of a wave

A

number of cycles per second passing a given point

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

define phase of a wave

A

measurement of the position of a certain point along the wave cycle

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

define phase difference

A

the amount one wave lags behind another

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

how can you work out the frequency of a wave?

A

f=1/time period

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

give the wave equation

A

v= fλ

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

what does an oscilloscope do?

A

displays waves from a signal generator as a function of voltage over time

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

what is a transverse wave?

A

a wave where oscillations are perpendicular to the direction of energy transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

give an example of a transverse wave

A

electromagnetic waves

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

what is a longitudinal wave?

A

a wave where oscillations are parallel to the direction of energy transfer

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

give a similarity and difference between a transverse and longitudinal wave

A

similarity- both transfer energy

difference- transverse have peaks/troughs whereas longitudinal have compressions and rarefactions

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

give an example of a longitudinal wave

A

sound waves

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

what is intensity?

A

rate of flow of energy per unit area at right angles to the direction of travel of the wave

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

give the intensity equation

A

I=power/area

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

what is the relationship between intensity and amplitude

A

intensity is directly proportional to amplitude squared

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

give a property of all EM waves

A

all travel at speed of light (3.8x10^8) in a vacuum

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

what are EM waves?

A

transverse waves that consist of vibrating magnetic and electric fields at right angles to each other and direction of travel

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

give a use of radio waves

A

radio transmission

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

give a use of microwaves

A

cooking
radar
tv transmissions

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

give a use of infrared radiation

A

heat detectors
night vision cameras
optical fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
give a use of visible light
human sight | optical fibres
26
give a use of ultraviolet light
sunbeds | security
27
give a use of x-rays
see damage to bones and teeth airport security scanners kill cancer cells
28
give a use of gamma rays
kill cancer cells | sterilisation of medical equipment
29
give the EM spectrum in order of increasing frequency and decreasing wavelength
``` radiowaves microwaves infrared radiation visible light ultraviolet x-rays gamma rays ```
30
what is a polarised wave?
a wave that only oscillates in one direction
31
what is the plane of polarisation?
the plane in which a wave vibrates in
32
what is plane polarisation?
polarising a wave so it only oscillates in one direction
33
how can a wave be polarised?
using a polarising filter that only transmits vibrations in one direction
34
can longitudinal waves be polarised?
no, only transverse waves can
35
how can you polarise microwaves?
using metal grilles - polarising filters won't work
36
describe why the intensity of microwaves drops to 0 when the wires of the metal grille are aligned with the direction of the microwaves
- the vibrating electric field of the microwave excites electrons in the metal grille - energy of incoming microwaves is absorbed and re-emitted in all directions - only a few re-emitted waves are vibrating in direction of microwave receiver - only microwaves in one plane are received - when wires and vibrations of the waves are aligned, more electrons are excited that when the grille and vibration of the waves are at right angles to each other- causes drop in intensity
37
define diffraction
the spreading out of waves as they pass through a narrow gap or go round an obstacle
38
what does the amount of diffraction depend on?
size of the gap compared to the λ
39
when do you get the most diffraction?
when the gap is the same size as the wavelength
40
how can you demonstrate diffraction in light using laser light?
-shining light through a narrow slit onto a screen. you can alter amount of diffraction by changing the width of the slit or -use a white light source and a set of coloured filters to see how wavelength varies for each colour and how diffraction changes
41
what does the diffraction pattern look like when the wavelength of a light wave is similar to the size of the slit?
pattern of light and dark fringes are seen
42
what is reflection of a wave?
wave is bounced back when it hits a boundary. | angle of incidence = angle of reflection
43
what is refraction of a wave?
wave changes direction when entering a different medium as a result of the wave slowing down or speeding up
44
if a wave slows down, does the wave bend towards or away from the normal?
towards
45
if a wave speeds up, does the wave bend towards or away from the normal?
away
46
what is the refractive index of a material?
measure of how much a material slows down light
47
define the absolute refractive index of a material
the ratio between the speed of light in a vacuum and the speed of light in that material
48
what is the equation for refractive index?
n=c/v
49
what is the refractive index of air?
1
50
what equation is given for a light ray passing across a boundary between 2 materials?
nsinθ = constant
51
give Snell's law
n1sinθ1 = n2sinθ2
52
when the angle os refraction is 90 degrees, what is the angle of incidence?
critical
53
what is total internal reflection?
when all light is reflected back into the material
54
how can you find the critical angle?
sinC= 1/n
55
define superposition
when two or more waves pass through each other
56
give the principle of superposition
when two or more waves, cross, the resultant displacement equals the vector sum of the individual displacements
57
what are the two types of interference?
constructive and destructive
58
explain constructive interference
two points on a wave meet to create a larger displacement. e.g crest + crest gives a bigger crest
59
explain destructive interference
two points on a wave meet to give no displacement | e.g crest + trough meet to give nothing
60
describe what is meant when a wave is 'in phase'
- points on adjacent waves on at the same position, have the same displacement and velocity - two points in phase interfere constructively - phase difference of 0 or a multiple of 360 degrees is in phase (2pi)
61
describe what is meant when a wave is 'out of phase'
- points on adjacent waves that are not in the same position, have different displacements and different velocities - phase difference of odd number multiples of 180 (pi radians)
62
how can you get interference patterns from two sources?
the two sources must be coherent
63
define coherent
same wavelength same frequency fixed phase difference
64
what does constructive or destructive interference depend on?
path difference
65
when would constructive interference occur?
when path difference = nλ (n=integer)
66
when would destructive interference occur?
when path difference = (2n+1)λ/2 | or (n+0.5)λ
67
how can you demonstrate interference for EM radiation?
Young's double slit experiment
68
describe Young's double slit experiment
-laser light is coherent and monochromatic -slits must be same size as wavelength of laser light so it is diffracted -pattern of light and dark fringes is created depending on whether constructive or destructive interference occurs -work out wavelength with Young's double slit formula fringe spacing, x = λD/a
69
does young's experiment support the wave or particle model of light?
wave
70
what other practical can be used to work out the wavelength of light?
diffraction grating creates bright central line called zero order and other maxima and minima are first, second orders etc.

physics content ocr a (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions