Brainscape's Knowledge GenomeTM

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


See full index

Physics > P11,P12- Waves > Flashcards

P11,P12- Waves Flashcards

1
Q

What is a wave

A

A wave is a means of transferring energy from one place to another without a transfer of matter between the two points

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

What are mechanical waves

A

Mechanical waves are vibrations that travel through a medium

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

Give an example of a longitudinal wave

A

Sound wave

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

What is the difference between a transverse and a longitudinal wave

A

In a transverse wave, the direction of energy transfer is perpendicular to the oscillation (wobbles). In a longitudinal wave,the direction of energy transfer is the same as the oscillation (straight)

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

What is meant by the frequency of a wave

A

The number of complete oscillations or waves each second

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

What are the two types of waves

A

Transverse , longitudinal

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

What are the crests in a wave

A

The top part of the wave

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

What is the amplitufe of a wave

A

Maximum displacement of a point on the wave from its rest position

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

What is the wavelength of a wave

A

Distance between the same point on two seperate waves. May be distance between crest on one wave and crest on the other.

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

What is frequency in a wave repressntation

A

Number of complete waves passing a certain point per second. Measured in (Hz).

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

What is the period of a wave

A

Amount of time it takes for a full cycle of the wave to be completed
Period=1/frequency

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

How do you find speed of sound in air

A

Set up a signal generator thats is connectedbto a speaker. Swt the frequency to 1kHz and have two microphones at same distance from speaker connected to an oscilstor. Play sound and slowly move one microphone away from speaker and keep going until the two waves on the oscilstor are alligned up. Now the microphones will be exactly one wavelength apart so measure distsance between two microphones.

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

What is a ray

A

Straight line showing the path of a wave travels along

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

What can a wave do when they meet the boundsry between two different materials

A

Reflected, absorbed, transmitted

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

What are electromagnetic waves

A

Group of transverse waves that all travel at the same speed in a vacum

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

What are the waves in the electromagnetic spectrum from left to right

A

Radio waves, micro-waves, infrared, visible light, ultraviolet,x-rays,gamma rays

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

What are the three things wa wave can do at a boundary

A

The waves can be absorbed
The waves can be reflect
The waves can transmit through the material

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

If a wave slows down at a boundary what way does it bend

A

Towards the normal

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

If a wave speeds up at a boundary what direction does it bend

A

Away from the normal

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

What is a normal in waves

A

A straight line that is 90° to the boundary

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

What is refaction

A

When a wave reaches the boundary of two material and changes direction

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

What is the angle of incidence

A

The angle between the incoming wave and the normal

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

What is the angle of reflection

A

The engle between rhe reflected wave and normal wave

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

What is specular reflection

A

What happens when parallel waves aare reflected in a single direction

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

What is diffuse reflection

A

When parrallel waves are reflected by a rough surface and reflected rays are scattered in different directions

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

What is the electromagnetic spectrum

A

A continous spectrum of all the possible wavelengths of electromagnetic waves

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

What increases when moving from left to right on the electromagnetic spectrum

A

Frequency increases

28
Q

What increases when moving from right to left in the electromagnetic spectrum

A

Wavelength increases

29
Q

When do electromagnetic waves transfer energy from and to

A

Electromagnetic waves transfer eneegy from a source to an absorber

30
Q

What are gamma rays and why/how are they produced

A

Gamma rays are high-energy electromagnetic waves which come from changes in the nuclei of the atoms. Unstable nuclei of radioactive atoms decay and give out particles. After particles are given out the nucleus might need to get rid of extra energy and does this buy giving out gamma rays

31
Q

At what speed do electromagnetic waves travel through a vacum

A

They all travel at the same speed

32
Q

What electromagnetic waves have the longest wavelength

A

Radio waves

33
Q

How can you produce radio waves

A

Using an alternating current (ac)

34
Q

What are the two things radio waves are mostly used for

A

Radio waves are mainly used for radio and tv signals

35
Q

What are radio waves sent out by and what are they received by

A

Radio waves are sent out by Transmitters and received by tv or radio receivers

36
Q

What are the three different lengths of radio waves

A

Long-wave radio
Medium-wave radio
Short-wave radio

37
Q

How are long-wave radio suited for their role

A

Long-wave radio have a wavelengths of 1-10km and therefore can be transmitted and received halfway round the world. They can diffract (bend) around the curved surface of the earth and hills into tunnels making it possible for radio signals to be received even if the recieved isnt in the line of sight of the transmitter

38
Q

How are short-wave radio suited for their role what what is their role

A

Short-wave radio have wavelengths of around 10-100m, they dont diffract around the earths curve but can still be received at large distances from the transmitter. They are reflected between the earth and the ionosphere (an electrically charged layer in the earths upper atmosphere). Short-wave radio are used for bluetooth to send data of short distances between devices without wires.

39
Q

What do radios and tv aerials have to be in line if sight of the transmitter

A

Because the short-wave radio doesnt bend around hills or travel far through things

40
Q

What type of waves are used for communication to and from satellites and why

A

Microwaves because the wavelenghs of microwaves can pass easily through the earths atmosphere without being completely reflected, refracted or absorbed so they can reach satellites

41
Q

Explain the process which satellites communications get sent out and received

A

The signal from a transmitter is sent out to space where it is picked up by a satellite receiver orbiting high above ground. The satellite transmits teh signal back to earth in a different direction where it is received by a satellite receiver on the ground

42
Q

Explain how micro-waves work in a microwave to cook food

A

The microwaves penetrate up to a few centimetres into the food before being absorbed and transferring the energy they are carrying to the thermal energy stores of the water molecules in the food causing the water molecules to heat up. This heat is transferred to the rest of the food molecules which cooks the food

43
Q

What is infrared radiation

A

Related to temperature. It is given out by all objects, the hotter the objects the more IR radiation it gives out. Infrared cameras can be used to detect infrared radiation and monitor temperature. If the object is hot its more red on the screen and if its cold its more purple

44
Q

What do fibre optic cables do in short terms

A

Use visible light to transmit data

45
Q

What are fibre optic cables

A

Thin glass or plastic fibres that carry data over long distances as pulses of visible light

46
Q

Describe the structure of a fibre optic cable

A

Glass fibre is inside cladding ehich protects the fibre and a light ray bounces back and forth inside the fibre

47
Q

What typw of radiation gives you a suntan

A

Ultraviolet radiation

48
Q

Why are x-rays used to see if a person has any broken bones

A

Because x-rays pass easily through flesh however not as easy through denser material like bones so its the amount of rsdiation absorbed or not absorbed in the body that gives an x-ray image

49
Q

How are x-rays and gamma waves used to treat people with cancer

A

High doses of x and gamma rays kill all living cells so they are directed to towards cancer cells to avoid killing too many healthy cells

50
Q

What are the two things that the amount of infrared radiation emitted from an object is dependant on.

A

The objects temperature and the material on the surface

51
Q

What is a leslie cube and what can you use them for

A

A hollow metal cube made out of alluminium whose four vertical faces have different surface types. e.g matt black paint, matt white paint, whiny metal and dull metal. They can be used to investigate infrared radiation emission by different surfaces.

52
Q

Explain theprocess of the practical of investigating infrared radiation

A

Place an wmpty leslie cube on a heat proof mat and fill it up with boiling water. What a minute for the cube ti warm up then hold a themometre against each of the four faces of the cube. They should all be the same temperature. Then hold an infrared detector at 10 cm away from one of the faces and record the amount of IR radiation it detects. Repeat this for all four sides. There should be more infrared radiation on certain faces of the cube due to the type of material and colour of the face aswell

53
Q

Why will more infrared radiation be detected around a black face of a leslie cube

A

Black absorbs more infrared radiation

54
Q

How can UV radiation be harmful to humans

A

UV damages surface cells which can lead to sunburn and cause skinnto age prematurely. Other effects can be skin cancer

55
Q

what can x-rays and gamma rays cause and why

A

They are both types of ionising radiation (they carry enough energy to knock electrons out of atoms) which cause gene mutation or cell destruction and cancer

56
Q

How can you measure risk of electromagnetic waves

A

You can measure risk by using radiation doss in siverts

57
Q

What way do the magnetic field lines go in a magnetic field

A

They always go from north to south

58
Q

What does the distance between each magnetic field line tell us

A

The closer the lines are the stronger the magnetic field, the further away you get the weaker the field is

59
Q

What are the two different types of forces

A

Attractive forces and repulsive forces

60
Q

What are the teo types of magnets

A

Permanent magnets and induced magnets

61
Q

What are permenant magnets

A

Magnets that produce their own magnetic field

62
Q

What are induced magnets

A

Induced magnets are magnetic materials thsn turn into magnets when put into a magnetic field

63
Q

What is the force between permenant and induced magnets

A

The force is always attractive

64
Q

How can you increase the strength of a magnetic field that a wire produces

A

By wrapping the wire into a coil and a solenoid

65
Q

If the field lines are closer together in a magnetic field what does that mean

A

The force is stronger

66
Q

What is a solenoid with an iron core called

A

An electromagnet

Physics (5 decks)

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