Brainscape's Knowledge GenomeTM

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


See full index

MED 107- MEDICAL PHYSICS II > 87. MRI: MAGNETISM AND ELECTROMAGNETISM > Flashcards

87. MRI: MAGNETISM AND ELECTROMAGNETISM Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards USMLE® Step 1 flashcards
1
Q
  1. Define: Magnetic Predisposition of a Substance.
A
  • it is the ability of external magnetic fields
  • to affect the nuclei of a particular atom
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  1. What is Magnetic Predisposition related to?
A
  • it is related to the Electron Configurations of the
    specific atom
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  1. What can be said about the state of a nucleus if it is surrounded by paired electrons?
A
  • the nucleus is protected
  • the nucleus is much less affected
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  1. What can be said about the state of a nucleus if it is surrounded by unpaired electrons?
A
  • the nucleus is not as protected
  • this means that the external magnetic fields can
    significantly affect it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. What are the 3 types of Magnetic Predisposition?
A
  1. Paramagnetism
  2. Diamagnetism
  3. Ferromagnetism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  1. What do Paramagnetic substances contain?
A
  • they contain unpaired electrons
  • these are found within the atom
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  1. Define: Magnetic Moment.
A
  • this is the small magnetic field that surrounds the atom
  • this atom contains unpaired electrons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  1. What happens to these Magnetic Moments when there is no external magnetic field present?
A
  • they will occur in a random pattern
  • they will cancel each other out
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  1. What happens to the Magnetic Moments of Paramagnetic Substances when an external magnetic field is present?
A
  • they will align with the direction of the field
  • the magnetic moments will add together
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  1. How do paramagnetic substances affect External Magnetic fields?
A
  • they affect them in a positive way
  • they cause a local increase in the magnetic field
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. What is an example of a Paramagnetic Substance?
A
  • Molecular O
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  1. What does this image show?
A
  • a Homogenous Magnetic Field
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  1. What does this image show?
A
  • a Paramagnetic Substance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  1. What does this image show?
A
  • a Paramagnetic substance in a Magnetic Field

STRONGER FORCES ARE PRESENT:
- when the lines of the magnetic field are attracted to
one another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. What do Diamagnetic Substances contain?
A
  • they contain paired electrons
  • these electrons are found within the atom
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  1. What happens to the Diamagnetic Substances when there is no external magnetic field present?
A
  • the Diamagnetic Substances show no net magnetic
    moment
17
Q
  1. What happens to the Diamagnetic Substances when an external magnetic field is applied?
A
  • the diamagnetic substances show a small Magnetic
    Moment
  • the moment opposes the applied field

SUBSTANCES LIKE THIS:
- are repelled by the Magnetic Field

18
Q
  1. What are some examples of Diamagnetic Substances?
A
  • Water
  • Fat
  • Calcium
  • most Biological Tissue
19
Q
  1. What does this image show?
A
  • this is a Homogenous Magnetic Field
20
Q
  1. What does this image show?
A
  • this is a Diamagnetic Substance
21
Q
  1. What does this image show?
A
  • this is a Diamagnetic Substance in the magnetic field
22
Q
  1. Define a Ferromagnetic Substance.
A
  • these are metals that are noticeably attracted to a
    magnet
23
Q
  1. What happens when a Ferromagnetic Substance comes into contact with a Magnetic Field?
A
  • there is strong attraction
  • there is alignment within the Ferromagnetic Substance
  • the Ferromagnetic substance travels in the same
    direction as the force applied
24
Q
  1. What does a Ferromagnetic Substance look like when there is no magnetic field applied?
A
25
Q
  1. What does a Ferromagnetic Substance look like when a Magnetic Field is applied to it?
A
26
Q
  1. What happens to a Ferromagnetic Substance when the Magnetic Field has been removed?
A

FERROMAGNETIC SUBSTANCES:
- retain their magnetisation
- they remain magnetic
- they are permanently magnetised
- they become permanent magnets

27
Q
  1. What can we see in this image?
A
  • this is a Ferromagnetic Substance in the magnetic field
28
Q
  1. What is an example of a Ferromagnetic Substance?
A
  • Iron
29
Q
  1. What can be said about the polarity of magnets?
A
  • they are Bipolar
  • they have two poles
  • a North pole and a South Pole
30
Q
  1. What happens when a Magnetic Field is exerted by a Magnet?
A
  • it produces Magnetic Field lines
  • these are also known as Lines of Force
  • they run from the magnetic North pole to the Magnetic
    South Pole
  • lines that run in this direction are known as Magnetic
    Lines of Flux
31
Q
  1. What is the Magnetic Flux Density?
A
  • it is the number of Magnetic Flux lines per unit area
32
Q
  1. Which 3 units is the strength of the Magnetic Field measured in?
A
  1. Gauss (G)
  2. Kilogauss (kG)
    - Gauss x 1 000
  3. Tesla (T)
    - Kilogauss x 10 000
33
Q
  1. What happens if two magnets are brought closer together?
A
  • there are forces of attraction and repulsion between
    them
34
Q
  1. What does the force of attraction or repulsion depend on?
A
  • the orientation of the magnetic poles relative to one
    another
35
Q
  1. What happens when we put like poles next to one another?
A
  • they will repel each other

IN THIS IMAGE:
- the space around the magnet consists of Magnetic
Field lines

36
Q
  1. What happens when we put opposite poles next to one another?
A
  • they will attract each other

IN THIS IMAGE:
- the space around the magnet consists of Magnetic
Field lines

37
Q
  1. Read through this summary.
    Does everything make sense?
A
  • yes

MED 107- MEDICAL PHYSICS II (108 decks)

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