Brainscape's Knowledge GenomeTM

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


See full index

RC1031 > EM Spectrum > Flashcards

EM Spectrum Flashcards

1
Q

What is a wave?

A
  • Waves transfer energy from one place to another without matter being transferred.
    E.g. Mexican wave.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the substance that waves travel through?

A

Some waves need a substance to travel through - MEDIUM

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

Name the two types of waves

A

Mechanical - require a medium e.g. sound waves.

Electromagnetic - can travel in a vacuum e.g. X-rays.

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

What is the difference between a longitudinal and transverse wave?

A

Longitudinal
Oscillations – same direction as direction of travel and energy transfer. 0

e.g. sound waves.

Transverse
Oscillations – at right angles to direction of travel and energy transfer.

e.g. Electromagnetic waves are transverse. N

Oscillation - repeated motion.

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

What waves require a transportation medium to propagate from one point to another?

A

Mechanical waves

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

What waves can travel in a vacuum?

A

Electromagnetic waves which are transverse.

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

What is electromagnetic radiation?

A
  • Electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry electromagnetic radiant energy.
  • Transverse waves + travel in a vacuum
  • Electromagnetic waves or radiation can be separated into seven
    distinct groups in the spectrum.
  • These are: Radio waves, microwaves, infrared, (visible) light,
    ultraviolet, X-rays, and gamma rays.
  • They are called the Electromagnetic Spectrum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the EM spectrum?

A
  • EM is the range of wavelengths that forms the electromagnetic radiation.
  • Different types of radiation occur in different parts of the EM spectrum.

Shorter wavelength to longer wavelength

S Gamma rays, X-ray, ultraviolet, visible, infrared, microwave and radio waves. L

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

List the properties of EM Radiation.

A
  • Can all travel in a vacuum
  • Are transverse waves
  • Consists of oscillating electric (up and down) & magnetic fields (side to side).
  • Propagates (to ‘move through’ or ‘transmit’) in straight lines
  • Crucial in imaging
  • Carries energy in a mass less form
  • All travel at the speed of light in a vacuum
    i.e. 3 x 108 m per sec (More accurately 2.999792458 x 108 m per sec) denoted by the symbol ‘C’ .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the amplitude of the EM waves?

A

Maximum electricity (or magnetic field) strength experienced at a particular point in space.

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

What is the wavelength of EM waves?

A

• Distance between two corresponding points on two successive waves.

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

What is frequency in regards to waves?

A

• The frequency of a wave is the number of waves produced by a source each second.

• It is also the number of waves that pass a certain point each second.

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

What is the unit of frequency?

A

• The unit of frequency is the hertz (Hz). It is common for kilohertz (kHz), megahertz (MHz) and gigahertz (GHz) to be used when waves have very high frequencies.

• For example, most people cannot hear a high-pitched sound above 20kHz, radio stations broadcast radio waves with frequencies of about 100MHz, while most wireless computer networks operate at 2.4GHz.

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

What is the equation for speed of EM radiation in a vacuum?

A

C = λ x v

c = constant speed/ Velocity (Speed of Light = 3 x 108 m/sec)
λ = wavelength (metre)
V = frequency (hertz)

wave speed (metre per second) = wavelength (metre) x frequency (hertz)

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

What is the equation of the energy of a photon?

A

E = h x v

E = Energy of a photon (joules)
h = Planck’s Constant (6.62 x 10-34 J sec )
V = frequency (hertz)

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

What are the units of measure used?

A

SI Unit Energy – Joule (J)
Alternative unit – Electron Volt (eV)

Relationship:
In physics, the electron volt is a unit of energy equal to approximately 1.6×10−19 Joule . By definition, it is the amount of energy gained by the charge of a single electron moved across an electric potential difference of one volt.

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

What is the effect of Frequency on EM energy?

A

EM radiation/wave energy is proportional to frequency.

EM radiation with high frequency has high energy. X-rays and gamma have high frequencies = Ionising

EM Radiation of lower frequencies (i.e., visible light, infrared, microwaves, and radio waves) is called non-ionising radiation

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

What are the effects of wavelength on EM energy?

A

EM radiation energy is inversely proportional to wavelength

I.e. Short wavelength = high energy EM radiation

E.g. X-rays and gamma radiation have short wavelengths.

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

Describe visible light.

A

Red has the lowest frequency + longest wavelength

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Richard Of York Gave Battle In Vain

Violet has the highest frequency + shortest wavelength

20
Q

Explain the relation between wavelength, frequency, and energy

A

EM Spectrum: decrease wavelength then frequency, and energy increases.

As wavelength decreases, frequency increases, and energy increases

21
Q

What are radio waves used for?

A

• MRI uses radio waves (within a magnetic field) to create an image

• Also used to accelerate electrons in a linear accelerator

22
Q

What are microwaves used for?

A
  • Can be used for treating liver metastasis
  • ‘Microwave ablation’ - treatment that uses heat from microwave energy to destroy cancer cells.
23
Q

What are infrared waves used for?

A
  • Used in breast imaging (thermography)
  • Hotter areas / objects emit more infrared radiation
    (emit shorter wavelength radiation)
24
Q

What is visible light used for?

A

Endoscope e.g. in the duodenum

25
Q

What is ultraviolet used for?

A
  • Germicidal radiation
  • treatment of skin conditions.
26
Q

What are gamma rays used for?

A
  • Radionuclide imaging (RNI)
  • Sealed and unsealed source radiotherapy
27
Q

Which modality does not use electromagnetic radiation?

A

Ultrasound

28
Q

Which radiation can travel through a vacuum?

A

Radio waves
Microwaves
Infrared
visible light
X-rays
Gamma rays

29
Q

Are waves on the electromagnetic spectrum, transverse or longitudinal?

A

Transverse

30
Q

What is meant by a transverse wave?

A

A wave where oscillations occur at right angles to the direction of travel and energy transfer.

31
Q

What field do transverse waves have?

A

Both an oscillating electric and magnetic field

32
Q

Rank the visible lights in order of frequency (lowest frequency at the top, highest frequency at the bottom)

A

Red, Orange, Yellow, Green, Blue, Indigo, Violet

33
Q

Rank the visible lights in order of wavelength (longest wavelength at the top, shortest wavelength at the bottom)

A

Red
Orange,
Yellow,
Green,
Blue,
Indigo,
Violet

34
Q

Rank the EM radiations in order of frequency. (Highest frequency at the top, lowest frequency at the bottom)

A

Gamma rays
X-rays
Ultraviolet
Visible light
Infrared
Microwaves
Radio waves

35
Q

Name the 7 different visible lights

A

Red, orange, yellow, green, blue, indigo, violet

36
Q

Rank the EM radiations in order of energy. (Highest energy at the top, lowest energy at the bottom)

A

Gamma rays
X-rays
Ultraviolet
Visible
Infrared
Microwaves
Radio waves

37
Q

Which EM radiation has the highest frequency and the shortest wavelength? Ultraviolet or visible light?

A

Ultraviolet

38
Q

Which has the lowest frequency and the longest wavelength?

Gamma rays, microwaves or Ultraviolet?

A

Microwaves

39
Q

What is the energy of a photon?

A

Planck’s constant multiplied by the frequency

40
Q

What is the SI unit of energy?

A

Joule (J)

41
Q

What is the unit of frequency?

A

Hertz

42
Q

What uses Radio waves?

A

MRI

43
Q

What does half-life (T1/2) describe ?

A

The amount of time needed for half of a sample of unstable atoms or particles to undergo decay.

44
Q

What are the types of radioactivity decay?

A

Alpha
Gamma
Beta

45
Q

What is alpha decay?

A

Alpha decay is the emission of 2 protons and 2 neutrons from an unstable neutrons. The daughter nuclide has an atomic number of 2 less than the parent nuclide.

RC1031 (9 decks)

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