Brainscape's Knowledge GenomeTM

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


See full index

Applied science level 3 btec > waves > Flashcards

waves Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is a wavelength?

A

The measurement of crest to crest.

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

What is an amplitude?

A

An amplitude is the maximum number of displacements in the oscillation cycle.

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

What is displacement?

A

How far the quantaty that is in oscillation has moved from its mean?

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

What are examples of transverse wave?

A

Electromagnetic waves and water ripples.

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

Example of a longitudinal wave?

A

Sound wave

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

What does the number of different displacement particles along the same direction along which the wave is propagating lead to?

A

It can cause compression and rarefactions which means the particles are close together and the wave are further apart.

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

What are longitudinal waves know for and why?

A

Pressure waves because the compression(particles close together) and the rarefractions(waves further apart) leading to changing speed.

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

what is superposition?

A

When the waves are in phase and they travel in same place and same time.

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

What happens when an electron moves down an energy level?

A

It becomes deexcited and releases photonic energy in the form of light.

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

What happens when an electron moves up an energy level?

A

Gets excited and absorbs photon energy light. The smaller the gaps which are at the highest energy level will produce a low frequency but a longer wavelength wave, the less the frequency the less the energy and so the plain the colour.

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

How is a wave formed?

A

The wave displaces from the equilibrium.

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

How is a stationary wave formed?

A

A stationary wave is formed by the wave displacing from the equilibrium. Then the
wave is in incidence and travels towards the boundary. Then the other wave travels away from the boundary and is superposed with the other wave and so they are inphased and so this leads to constructive inteference. Then as both the waves keep moving they alternate between in phase and out of phase. Out of phase causes them to be destructive inteference and this causes the waves to be stationary. Then the node is a fixed point along the boundary. Antinode is formed from constructive inteference.

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

What is refraction?

A

When light changes direction when hitting the boundary or when changing mediums.

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

What is total internal reflection?

A

When a light wave is flowing from a slow medium to a fast medium and then turns away from the normal for a while and then just stops. The incidence ray is then bigger than the critical angle. When it is incidence in the fibre optics cable then the incoherence light is sent down the endoscope and hits the object and then comes back up as coherence which produces a clear image of the object.

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

What is an analogue signal?

A

A signal that has different frequencies and amplitude can vary.

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

What is a digital signal?

A

A digital signal is made up of binary bits and has only one amplitude.

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

Factors that affect quality of adc?

A

The sampling rate and the sampling sensitivity.

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

What is sampling rate?

A

How many samples per second.

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

What is sampling sensitivity?

A

How close together the samples are.

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

Advanatages of digital signals?

A

Carry a lot of information in the same bandwith.
Can easily filter out inteferences because it can recognise it easier. Computer memory and processing is digital.

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

How is an image converted into digital signal?

A

Split up into different picture elemens or pixels. And each pixel has a binary code. The pixels are too small so we cant usually see it.

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

Disadvantages of digital signals?

A

It can take time to process the signal. It depends on the sampling rate,sampling sensitivity ect.

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

What do communication satellited do?

A

They recieve signals from ground stations.
Transmit them over a wide area. They use frequency from 1 to 400GHz.

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

Why is the uplink and downlink frequency different?

A

So that they dont intefer with each other.

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

What does the transponder do in a satelite when they recieve a signal?

A

Recieve it, filter it,amplify it and transmit it using a new frequency.

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

What does a mobile phone do?

A

It has its own transmitter that recieves and send signals. This is frequencies from 800MHZ to 2.6Ghz. They all networked together and the network covers the whole country.

26
Q

What is a network?

A

A network is a group of devices linked together. A network may be wired which uses cables or wireless e.g bluetooth or wifi. Devices in a wifi network is connected to a local hub or router in a range of 10mm. Both wifi and bluetooth operate at a frequency at a 2.6Ghz.

27
Q

What is bluetooth?

A

Bluetooth does not need to connect to wifi as it can communicate. The range of bluetooth is 10m. Devices that use batteries use bluetooth as its power needs are low. Bluetooth can allow music and speech but is not good for high quality videos as it does not carry the same information required for that as wifi does.

28
Q

What is infrared?

A

Eg. a tv remote, have a range of just a few metres and need a clear sight of line to work. Infrared has a high frequency but the information is sent as pulses . The frequency of infrared is 40Khz.

29
Q

What type of mouthpiece is important and how for the fundamental frequency?

A

Flute and oboe behave like an open end. The mouthpiece will affect fundamental frequency and harmonics produced.

30
Q

What does a differaction grating do?

A

Measures the wavelength of the elements and the different colours.

31
Q

What is a wavelength?

A

The distance between the adajacent particles oscilatting in phase.

32
Q

What is a longitudinal wave?

A

A particle osicllating parrallel to the direction the wave is travelling in.

33
Q

Meaning of coherent sources?

A

They have the same frequency,imilar amplitudes and in phase.

34
Q

Why do waves sometimes cause constructive or destructive inteference?

A

Depends on where the destination is. The waves will start of in phase but then they could arriv ein phase which will lead to constructive inteference and lead to twice the amplitude or the waves will arrive in antiphase and lead to destructive inteference.

35
Q

What does it mean if a wave refracts by entering a dnese medium?

A

This means the wave will travel from air to glass and so the wave will travel from fast o slow and it will bend towards the normal.

36
Q

What does it mean if waves travel to a less dense medium?

A

Wave will travel from glass to air and so will bend away from the normal the wave will speed up.

37
Q

Equation for refractive index?

A

n=c/v
n=sin i/sin R

38
Q

What is the use of fibre optics cable?

A

Used for communications and they can carry digital signals in the form of pulses of lights.

39
Q

What is a signal?

A

A signal is information travelling from one place to another.

40
Q

Examples of signals and what are their wavelengths?

A

Signals could be television signal(radio waves), Electrical signal in a wire, internet signal goring to your computer(infrared or visible), mobile phone signal(microwaves),wifi signal(radio waves) and bluetooth signal(radio waves).

41
Q

What are examples of digital signals?

A

Internet,mobile phone, bluetooth, wi-fi,digital television and digital radio.

42
Q

How is analouge signal converted into a digital signal?

A

It is convertered by being sampled many times a second the value of voltage is looked at by the converter and then converts it into a binary code.

43
Q

What is a bandwitdth?

A

Part of the electromagnetic spectrum.

44
Q

Why do nearby cell phones use different frequencies?

A

So that they dont intefer with each other.

45
Q

Why do portable devices(use batteries) have low power needs?

A

Because they dont transmit huge amount of information and power needs are low.

46
Q

Before devices can send information to each other what must they do?

A

They must first pair. This involves sending a few short messages. This allows them to recognise each other and decide how they are goring to communicate. This stops information getting lost and jumbled and there is acknowledgement when messages are recieved. There may be security features e.g. password and encryption,to protect data.

47
Q

What is a differaction grating?

A

Series of regular lines on it that block parts of a wavefront.

48
Q

What happens when atoms get excited?

A

They give of different colours.

49
Q

Equation for frequency?

A

Frequency=velocity divided by the wavelength.

50
Q

How is a stationary wave formed on a guitar string?

A

Formed by reflecting towards the end and interfering with each other.

51
Q

Which harmonic has the lowest frequency?

A

First harmonic

52
Q

What does each loop represent?

A

Half a wavelength so first harmonic will have a 0.5 wavelength.

53
Q

Why does every instrument has its own tone?

A

Because we get a mixture of different harmonics when pluck it.

54
Q

What does the certain frequency at which a string oscilates at depend on?

A

The wavelength of the stationary wave on a string and speed of a wave on a string.

55
Q
A
56
Q

What is resonance?

A

When an object is made to oscillate at its natural frequency we get large amplitude oscillations. This is called resonance.

57
Q

How resonance can be useful?

A

Musical instruments to get louder and clearer,water resonate in microwave ovens and tv ariels use resonance to get a stronger signal.

58
Q

When may resonance be an issue?

A

Wind may make buildings e.g bridges oscillate dangerously,
Skycrapers may oscillate due to eartcrakes and when machinery resonates e.g washing machines,it may break.

59
Q

What is intensity?

A

Wave carrying energy.

60
Q

If a pipe is open at both ends what does this mean?

A

There is an antinode at both ends. And the wavelength will be four times its length.

61
Q

What are the different ways you can change the note produced by the instrument?

A

Changing the length of air column- a longer column will have a bigger wavelength and so lower fundamental frequency.
Opening and closing holes along the air column.
Changing the way you use your lips to produce the vibrations.

62
Q

What are other factors that affect frequency produced by the instrument?

A

Flute and oboe mouthpieces behave like an open end. Clarinet and a trumpet mouthpiece behave like a closed end. These have a harsher/brighter sound because only the odd harmonics are present.

63
Q
A
63
Q
A
63
Q
A
63
Q
A
63
Q
A

Applied science level 3 btec (7 decks)

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