Brainscape's Knowledge GenomeTM

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


See full index

MPI > L1&2 General > Flashcards

L1&2 General Flashcards

1
Q

MPI is most likely to find subsurface discontinuities in what kind of steels?

A

Soft steels with high permeability

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

Cracks caused by alternating stresses above a critical level are called what?

A

Fatigue cracks

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

What is the magnetic flux density in the centre of a bar magnetized with a headshot?

A

Zero

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

Describe the magnetic flux density on the inside surface of a ferromagnetic tube magnetized with a central conductor?

A

Magnetic flux will be the highest

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

The prod method would be most sensitive to cracks where?

A

Parallel to a line connecting the prod contact points

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

What is the common rule of thumb to use for current required in circular magnetization?

A

1000 ampere turns per 25 mm diameter

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

For direct contact magnetizing methods, current should be flowing in what direction relative to expected discontinuities?

A

Parallel

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

The magnetic field outside a conductor decreases…

A

In a linear manner

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

How is the magnetic field strength at the surface of a magnetic conductor compared to a non magnetic conductor?

A

The same

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

What PARTICLES are the most sensitive?

A

Dry particles

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

A advantage to this method is that it has superior sensitivity to subsurface cracks.

A

Dry method

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

A disadvantage to this method is that it doesn’t have excellent detection of completely subsurface cracks…

A

Wet method

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

An advantage of this method is its ease of bath recovery and reuse..

A

Wet method

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

Describe fluorescent dyes:

A

Dyes that receive light at one wavelength and re-emit light of another wavelength

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

What’s the most common way to demag small test pieces?

A

Pass it through an AC coil

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

How can you remove MPI indications that are due to cold work?

A

Heat treating

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

What will a continuous linear indication along the centre of a fillet weld most likely to be?

A

A root indication

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

A minimum of how many mag operations is required when orientation of likely indication is unknown?

A

Minimum of 2

19
Q

What type of indications are produced when flux lines are parallel to a discontinuity?

A

None

20
Q

A split coil would mostly likely be used with…

A

A portable mag unit

21
Q

What is the most common harmful effect of exposure to black lights?

A

Eyeball fluorescence

22
Q

What magnetic field may be present without any external evidence?

A

Circular

23
Q

What are irregularly shaped, checked and scattered marks usually caused by local friction overheating?

A

Grinding cracks

24
Q

What is it called when you assess whether a discontinuity will have a detrimental effect on the part?

A

Evaluation

25
Q

What is it called when you’re measuring and recording discontinuities?

A

Reporting

26
Q

What is it called when you’re judging from an indication what the cause and nature are?

A

Interpretation

27
Q

Surrounding an electromagnet, just prior to reversal, the magnetic field is the…

A

Strongest

28
Q

Where are the lines of flux/magnetic force contained in a circularly magnetized ferromagnetic bar?

A

Within and around the part

29
Q

What are 3 advantages of AC?

A
  1. Most readily available
  2. Equipment can be made lighter
  3. Leaves part demagnetized
30
Q

What current would be best to detect fatigue cracks?

A

AC

31
Q

On a small forging, indications appear as some sharp and some broad & fuzzy, what are these most likely to be?

A

Magnetic writing

32
Q

Piping is what type of discontinuity?

A

Inherent

33
Q

What is the common rule of thumb for circular magnetization?

A

1000 amps/25 mm of diameter

34
Q

What is the best method to use on a large casting?

A

DC

35
Q

What is the ideal black light wavelength?

A

365 nm

36
Q

What is the max white light intensity in darkened conditions?

A

21.5 lux (2 ft. candles)

37
Q

What is the white light intensity for inspecting with black and white contrast paint?

A

1074 lux or 100 ft. candles

38
Q

What is are the properties of a diamagnetic material?

A

Very weak negative attraction

39
Q

What is the advantage of half way direct current over straight DC?

A

It improves particle mobility

40
Q

Why is the wet method better for fine defects?

A

More particle mobility

41
Q

Localized poles caused by a break have 2 names:

A
  1. Concurrent

2. Consequent

42
Q

More permeable allows particles to what?

A

Become more dense

43
Q

What is the wavelength of the electromagnetic spectrum?

A

400-700 nm

MPI (10 decks)

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