Brainscape's Knowledge GenomeTM

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


See full index

A Level Physics OCR B > Chapter 6 > Flashcards

Chapter 6 Flashcards

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

What does the principle of superposition state?

A

That when 2 or more waves overlap (superpose), the resultant displacement at a given instant and position is equal to the sum of the individual displacements at that instant and position.

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

A wave transfers energy away from [ ]

A

It’s source

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

A progressive (moving) wave carries [ ] and usually information from one place to another without transferring any [ ]

A

Energy

Material

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

How can you tell that EM waves carry energy?

A

They heat things

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

How can you tell that X-rays and Gamma rays carry energy?

A

They knock electrons out of their orbits, causing ionisation

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

How can you tell that sound waves carry energy?

A

They cause things to vibrate

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

How can you tell that water waves carry energy?

A

Wave power can be used to generate electricity

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

Since waves carry energy, the source of the wave [ ]

A

Loses energy

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

Define Displacement (X, m)

A

How far a point on the wave has moved from its undisturbed position

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

Define Amplitude (a, m)

A

Maximum displacement

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

Define Wavelength (λ, m)

A

The length of one whole wave

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

Define Period (T, s)

A

The time taken for a whole vibration

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

Define Frequency (f, Hz)

A

The number of vibrations per second passing a given point

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

Define phase difference

A

The amount by which one wave lags behind another wave (degrees or radians)

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

What is intensity?

A

The rate of flow of energy per unit area perpendicular to the direction of travel of the wave

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

Equation for intensity

A

Intensity (I, Wm⁻²) = Power (P, W) / Area (A, M²)

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

When does superposition happen?

A

When 2 or more waves pass through each other

18
Q

Superposition: What happens at the instant the waves cross?

A

The displacements from each wave combine

19
Q

The principle of superposition:

A

When 2 or more waves cross, the resultant displacement = the vector sum of the individual displacements

20
Q

Interference can be [ ] or [ ]

A

Constructive or Destructive

21
Q

What is total destructive interference?

A

When a peak and a trough are of equal size and they completely cancel each other out

22
Q

When is destructive interference not total?

A

When the waves are not the same size

23
Q

What are the arrows called, that represent wave superposition?

A

Phasors

24
Q

In [ ] means in step

A

Phase

25
Q

2 points on a wave are in phase if they are both at the [ ] in the [ ].

A

same point

wave cycle

26
Q

360° = ? Radians

A

2π Radians

27
Q

Describe the waves that are in phase

A

Points that have a phase difference of 0 or a multiple of 360° are in phase. Their phasors point in the same direction.

28
Q

Describe the waves that are in anti-phase

A

Points with a phase difference of odd-number multiples of 180°. Their phasors point in opposite directions.

29
Q

To get interference patterns the 2 sources must be [

A

Coherent.

30
Q

Define coherent

A

2 waves are coherent if they have the same wavelength and frequency and a fixed phase difference between them.

31
Q

Define path difference:

A

The amount by which the path travelled by one wave is linger than the path travelled by the other wave

32
Q

Describe the situation where you will get constructive interference from 2 waves

A

At any point an equal distance from both sources (coherant and in phas) or where the path difference os a whole number of wavelengths
Path difference = nλ

33
Q

Describe the situation where you will get total destructive interference from 2 waves

A

At any point where the path difference is an odd number of half wavelengths
Path difference = (2n+1)λ / 2 = (n + 1/2) λ

34
Q

What happens when a wave passes through a gap roughly the same width as its wavelength?

A

The waves spread out.

35
Q

What does diffraction alter?

A

ONLY how far the wave spreads out.

36
Q

What does the zeroth, first and second order represent?

A

The maximums produced at a path difference of zero, one and two wavelengths.

37
Q

What equation can we use to determine the wavelength of light passing through two slits? What can we also use this for?

A

dsin θ = n λ. Diffraction gratings.

38
Q

What difference does having a diffraction grating vs two slits make?

A

Brighter image, sharper fringe pattern and can also spread white light out into its component colours because each wavelength of light will produce a maximum at a different angle.

39
Q

Line separation=

A

1/number of lines per metre

40
Q

Snells Law-

A

n=sini/sinr=C1stmedium/C2ndMedium

A Level Physics OCR B (20 decks)

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