Brainscape's Knowledge GenomeTM

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


See full index

Physics > Topic 5 - light and the electromagnetic spectrum > Flashcards

Topic 5 - light and the electromagnetic spectrum Flashcards

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

What is total internal reflection?

A

When a light is completely reflected back at a boundary between two mediums
It occurs when light meets a less dense medium at an angle of incidence larger than the critical angle

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

What is the critical angle?

A

The angle of incidence which causes the angle of reflection to be 90 degrees

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

What determines the colour of visible light waves?

A

The wavelength and frequency of the light waves

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

What colour of visible light has the highest frequency?

A

Blue

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

What colour of visible light has the largest wavelength?

A

Red

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

What is meant by ‘speculate reflection’?

A

Rays are reflected from a smooth surface in a single direction

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

WhT is meant by ‘diffuse reflection’?

A

Reflection from a rough surface which causes scattering

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

How does a red colour filter work?

A

A red filter absorbs all wavelengths of light other than those in the red range of the spectrum
So only red light passes through

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

What is meant by ‘opaque’?

A

Not see through

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

What governs the colour of an opaque object?

A

Different objects reflect different wavelengths of light by different amounts
The wavelengths that are most strongly reflected determine the colour

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

What happens to the wavelengths of light that aren’t reflected by any opaque object?

A

Any wavelengths that aren’t reflected are absorbed by the object

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

What colour does an object appear if all wavelengths are reflected by equal amounts?

A

White

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

What colour does an object appear if all wavelengths are absorbed?

A

Black

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

What type of waves are electromagnetic waves?

A

Transverse

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

What do electromagnetic waves transfer?

A

Energy (not matter))

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

What type of spectrum do electromagnetic waves form?

A

A continuous spectrum

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

List the order of the electromagnetic spectrum in order of increasing wavelength

A

Gamma, X-rat, Ultraviolet, visible, infrared, microwaves, radio

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

What is the highest frequency electromagnetic wave?

A

Gamma waves

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

What is the highest energy electromagnetic wave?

A

Gamma waves

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

What properties are shared by all electromagnetic waves?

A

All transverse
All travel at 3x10^8 m/s
Can all travel through a vacuum

21
Q

What range of frequencies of electromagnetic waves can be detected by the human eye?

A

400-700 manometers

22
Q

How do the speeds of EM radiation differ in a vacuum and in air?

A

They travel at the same speed

23
Q

What can happen when radiation strikes an object?

A

It can be transmitted, reflected or absorbed

24
Q

What do all objects emit and absorb?

A

Infrared radiation

25
Q

WhT happens to the quantity of infrared radiation emitted by an object as temperature increases?

A

The hotter the object, the more infrared radiation it will emit

26
Q

What happens to the type of radiation emitted bu an object as temperature increases?

A

The hotter the body the shorter the wavelength of radiation releases

27
Q

What is required for an object to be at a constant temperature?

A

The body would need to emit radiation at the same rate it absorbs it - it needs to radiate at the same average power that it absorbs

28
Q

What is meant by intensity?

A

The power transferred per unit area, it is a measure of the energy transferred by a wave

29
Q

What will happen if the average power that an object radiates is less than it absorbs?

A

The temperature of the object will decrease

30
Q

Hat can be said about the rates of emission and absorption for an object increasing in temperature?

A

The object is absorbing radiation faster than it is emitting it

31
Q

Give two factors that affect the temperature of the earth

A

The amount of reflection of radiation into space

The earth”’s rate of absorption and emission of radiation

32
Q

How does the Earth’s atmosphere effect radiation?

A

It absorbs of reflects radiation from the sun, preventing it from reaching earth
Some is allowed to pass through and warms the earth

33
Q

What happens to the radiation emitted from the earth?

A

It is absorbed and re-emitted in all direction but greenhouse gases, resulting in the greenhouse effect which warms the earth

34
Q

What type of waves can be produced by oscillations in an electrical circuit?

A

Radio

35
Q

How can radio waves created an alternating current in a circuit?

A

When they are absorbed, they induce oscillations in a circuit with the same frequency as the waves themselves

36
Q

Where do gamma rays originate from?

A

Changes in the nuclei of atoms

37
Q

What health effects can untraviolet waves cause?

A

Premature skin aging

Can increase the risk of developing skin cancer

38
Q

What health effects can X-rays and gamma rays cause?

A

Are ionising radiation so can cause mutations in genes

Can lead to increased risk of developing various cancers

39
Q

What health effects can infrared rays cause?

A

Can cause burns to skin/tissue

40
Q

How does electromagnetic radiation affect electron arrangement in atoms?

A

Absorption or emission of em radiation can cause electron arrangement to change

41
Q

How do atoms become ions?

A

By losing or gaining outer electrons

42
Q

What are the effects of body cells absorbing radiation?

A

Large amounts can damage cells

Smaller amounts cause mutation, Causing cells to divide rapidly, which can lead to cancer

43
Q

State and explain the main use of radio waves

A

Communication

Because they are long wavelength and can travel long distances without losing quality

44
Q

State and explain the main use of microwaves

A

Cooking, as microwaves are absorbed by and heat fat/water in foods

45
Q

State uses of infrared radiation

A

Cooking food
Infrared cameras
Short range communication

46
Q

State and explain uses of UV radiation

A

Sterilisation, as it kills bacteria
Energy efficient lamps, as it radiates low heat but high energy
Sun tanning

47
Q

State and explain uses of X-rays

A

Medical imaging and treatment p, because they are very high energy and can easily penetrate body tissues

48
Q

State a use of gamma rays

A

Medical treatments, such as radiotherapy in the treatment of cancer

49
Q

Which waves of the EM spectrum are regarded as most dangerous?

A

Gamma and X-rays as they have the highest energy

Physics (12 decks)

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