L1 Flashcards
1
Q
- Magnetic particle is a nondestructive testing
method used for:
a. locating surface and near surface
discontinuities in aluminum.
b. locating surface and near surface
discontinuities in steel.
c. finding and measuring material separation.
d. measuring flux density.
A
b. locating surface and near surface
discontinuities in steel.
2
Q
- Magnetic particles are available in different
colors:
a. for color contrast with the part surface thereby
enhancing detection of indications.
b. to enhance the detecti~n of indications by
allowing background color matching.
c. to determine if an indication is surface or
subsurface.
d. to indicate different magnetic flux values.
A
a. for color contrast with the part surface thereby
enhancing detection of indications.
2
Q
Which of the following can be magnetized?
a. iron
b. copper
c. aluminum
d. magnesium
A
a. iron
3
Q
- Ferromagnetic material is:
a. strongly attracted by a magnet.
b. not highly saturated by magnetic fields.
c. a material with a 0 permeability measurement.
d. not capable of being magnetized.
A
a. strongly attracted by a magnet.
4
Q
- The permeability of a material describes:
a. the ease with which it can be magnetized.
b. the depth of the magnetic field in the part.
c. the length of time required to demagnetize it.
d. the ability to retain the magnetic field.
A
a. the ease with which it can be magnetized.
5
Q
- The retentivity of a material describes:
a. the ease with which it can be magnetized.
b. the depth of the magnetic field in the part.
c. the length of time required to demagnetize it.
d. the ability to retain the magnetic field.
A
d. the ability to retain the magnetic field.
6
Q
The magnetic field is strongest when:
a. the magnetizing voltage is flowing.
b. the magnetizing current is flowing.
c. the material exhibits high coercive forces.
d. the magnetizing current is not flowing.
A
b. the magnetizing current is flowing.
7
Q
- If a crack exists in a circular magnet, the
attraction of magnetic particles to the crack is
caused by:
a. a coercive force.
b. a leakage field.
c. a Doppler effect.
d. a high reluctance at the crack.
A
b. a leakage field.
7
Q
- The unit usually used to denote flux density is:
a. gauss.
b. henry.
c. farad.
d. ampere.
A
a. gauss.
8
Q
- Which statement is true when related to magnetic
lines offorce?
a. They are often forced to cross due to part
geometry.
b. They are most dense at the poles of a magnet.
c. They seek the path of most resistance.
d. They cannot be detected.
A
b. They are most dense at the poles of a magnet.
9
Q
- Magnetic flux lines that are parallel to a
discontinuity produce:
a. strong indications.
b. weak indications.
c. no indications.
d. fuzzy indications.
A
c. no indications.
10
Q
- A part is adaptable to magnetic particle
inspection if:
a. it is attached to an electrostatic field.
b. the material is ferromagnetic.
c. the material is non-ferrous.
d. the material is an electric conductor.
A
b. the material is ferromagnetic.
10
Q
- What rule describes the direction of current flow
( + to -) when lines of magnetic force surround a
conductor?
a. left-hand rule
b. right-hand rule
c. flux rule
d. reluctance rule
A
b. right-hand rule
11
Q
- The magnitude of the residual magnetic field in a
specimen is dependent on:
a. the length-to-diameter ratio (UD).
b. the strength of the applied magnetizing force.
c. the right-hand rule.
d. the left-hand rule.
A
b. the strength of the applied magnetizing force.
12
Q
- The proper number of ampere-turns for a given
test specimen being examined by longitudinal
magnetism is determined by:
a. its length and diameter.
b. the material.
c. the diameter and the material.
d. its diameter.
A
a. its length and diameter.
13
Q
- A circular field may be induced into a specimen
by:
a. placing the part in an energized coil.
b. passing current directly through the part.
c. passing a magnetic field through the part.
d. placing the part in a north-south orientation.
A
b. passing current directly through the part.
14
Q
- An electrical yoke produces:
a. a longitudinal field.
b. a circular field.
c. alternating fields.
d. a swinging field.
A
a. a longitudinal field.
15
Q
- An energized coil around the part produces:
a. a circular field.
b. a longitudinal field.
c. an intermittent field.
d. a field dependent on the type of current
applied.
A
b. a longitudinal field.
16
Q
- In longitudinal magnetization the proper term for
calculating magnetizing force is:
a. amperes.
b. ampere turns.
c. watts.
d. ohms.
A
b. ampere turns
17
Q
- Magnetic lines of force:
a. travel in straight lines.
b. form a closed loop.
c. are randomly oriented.
d. overlay in highly ferromagnetic materials.
A
b. form a closed loop.
18
Q
- A magnetic particle buildup from a discontinuity
is strongest when the discontinuity is oriented:
a. 180 degrees to the magnetic flux flow.
b. 45 degrees to the magnetic flux flow.
c. 90 degrees to the magnetic flux flow.
d. 90 degrees to the current flow.
A
c. 90 degrees to the magnetic flux flow.
19
Q
- A specimen may be demagnetized by which of
the following methods?
a. Heat treatment below the curie temperature.
b. Placing the part in an alternating current coil.
c. Placing the part in reversing and decreasing
direct current fields.
d. Applying a direct current yoke and removing
it from the part.
A
c. Placing the part in reversing and decreasing
direct current fields.
20
Q
- Which of the following is an advantage of
magnetic particle testing over penetrant testing?
a. It does not require post-cleaning of the part.
b. It requires direct access to the surface of the
part.
c. It can detect near-surface discontinuities.
d. It requires ~ shorter dwell time to produce
results.
A
c. It can detect near-surface discontinuities.
21
Q
- The amount of amperage used for magnetic
particle inspection using the prod method is
determined from the:
a. type of material.
b. distance between the prods.
c. diameter of the part.
d. total length of the part.
A
b. distance between the prods.
22
25. The flux within and surrounding a magnetized
part or around a conductor carrying a current is
known as:
a. the saturation point.
b. a magnetic field.
c. the ferromagnetic field.
d. the paramagnetic field.
b. a magnetic field.
23
26. The areas on a magnetized part from which the
magnetic field is leaving or returning into the
part are called:
a. salient points.
b. defects.
c. magnetic poles.
d. nodes.
c. magnetic poles.
24
27. A metal that is difficult to magnetize is said to have:
a. high permeability.
b. low permeability.
c. low coercive force.
d. low retentivity
b. low permeability.
25
28. The magnetism that remains in a piece of
magnetizable material after the magnetizing force
has been removed is called the:
a. tramp magnetism.
b. residual magnetism.
c. damped magnetism.
d. permanent magnetism.
b. residual magnetism
26
31. Which magnetic particle application technique is
the most sensitive?
a. continuous
b. residual
c. interrupted
d. counter-current
a. continuous
27
29. Subsurface discontinuity indications usually
appear:
a. sharp and distinct.
b. sharp and wide.
c. wide and fuzzy.
d. high and loosely held.
c. wide and fuzzy.
28
30. Which residual field is most difficult to demagnetize?
a. longitudinal
b. circular
c. vector
d. binodal
b. circular
29
32. Fluorescent magnetic particle indications should
be inspected under:
a. any light.
b. a neon light.
c. an ultraviolet light.
d. a fluorescent light.
c. an ultraviolet light.
30
33. Inspecting a part by magnetizing, removing the
current flow, then applying the medium is called
the:
a. continuous method.
b. wet method.
c. residual method.
d. dry method.
c. residual met
31
34. Which of the following is the most effective method for the detection of near surface defects?
a. Dry residual method using DC with surge.
b. Wet continuous method using half-wave rectified current.
c. Wet residual method.
d. Dry continuous method using half-wave rectified current with prods.
d. Dry continuous method using half-wave
rectified current with prods.
32
35. A curve is sometimes drawn to show graphically
the relation of the magnetizing force to the
strength of the magnetic field produced in a
certain material. This curve is known as the:
a. magnetic force curve.
b. hysteresis curve.
c. saturation curve.
d. induction curve.
b. hysteresis curve.
33
36. What method of applying particles provides
greater sensitivity in locating subsurface weld
discontinuities?
a. continuous
b. residual
c. circular
d. longitudinal
a. continuous
34
37. When magnetizing a weld in two directions, and
if the current used in the first direction is 750 A
and the current in the second direction is 400 A,
which of the following is true?
a. The part should be checked to see if
demagnetization between operations is
necessary.
b. No precautions should be taken before the
second operationc. This is not a valid technique.
d. There is no need to magnetize a weld in two
directions.
a. The part should be checked to see if
demagnetization between operations is
necessary.
35
38. When there is absolutely no pattern or distribution of magnetic particles on the part, the possible
cause is that:
a. the amperage setting is too high.
b. the amperage setting is too low.
c. the particle bath strength is too high.
d. the part is made of steel with high retentivity.
b. the amperage setting is too low.
36
39. What are three causes of nonrelevant indications?
a. lack of fusion, change of section thickness,
grinding cracks
b. change of section thickness, heat affected
zones, drilled hole near surface
c. very high amperage, drilled hole near surface,
blow holes
d. drilled hole near surface, very high amperage,
lack of fusion
b. change of section thickness, heat affected
zones, drilled hole near surface
37
40. Using the residual test method, a number of parts
are magnetized and laid on a rack prior to
application of magnetic particles. Why is it
important that they do not rub or touch each
other?
a. There is a possible loss of the magnetic field.
b. It may cause magnetic writing.
c. It may damage the part.
d. It makes parts hard to handle.
b. It may cause magnetic writing.
38
41. The point at which the magnetism in a material
cannot be increased even though the magnetizing
force continues to increase is known as the:
a. salient pole.
b. saturation point.
c. residual point.
d. remnant point.
b. saturation point.
39
42. Which type of current produces a skin effect on
the surface of the part?
a. alternating current
b. direct current
c. half-wave rectified
d. full-wave rectified
a. alternating current
40
43. When using the wet method, why should a high
velocity flow of wet method bath over surfaces
following removal of the magnetizing current not
be used?
a. It may wash away a fine or weakly held
indication.
b. This is not a problem.
c. It may splash particles into eyes.
d. None of the above is correct.
a. It may wash away a fine or weakly held
indication.
41
44. Residual magnetic particle inspection may be
used when:
a. parts are irregular in shape.
b. parts are highly retentive.
c. parts are highly stressed.
d. evaluating continuous method indications
b. parts are highly retentive.
42
45. Magnetic particle inspection is not a reliable
method of detecting:
a. laps.
b. deep internal cavities.
c. cracks.
d. seams.
b. deep internal cavities.
43
46. The wet fluorescent magnetic particle inspection
method is the same as the visible wet magnetic
particle method except that the fluorescent
magnetic particle inspection method requires:
a. an ultraviolet light.
b. a higher current.
c. a different machine.
d. alternating current.
a. an ultraviolet light.
44
47. A discontinuity open to the surface produces an
indication which is:
a. sharp and distinct.
b. wide and indefinite.
c. crisscrossed.
d. high and fuzzy.
a. sharp and distinct.
45
48. Which of the following will produce circular
magnetism?
a. passing current through a coil
b. placing the test part in a solenoid
c. yokes
d. passing current through prods
d. passing current through prods
46
49. When using the wet continuous method, the flow
of suspension from the hose should be shut off:
a. immediately after applying the current.
b. immediately before applying the current.
c. while the current is flowing.
d. 30 seconds before applying the current.
b. immediately before applying the current.
b. immediately before applying the current.
47
50. The strongest magnetic field in a coil is at the:
a. outside edge.
b. inside edge.
c. center.
d. end.
b. inside edge.
48
51. To detect lengthwise discontinuities on the inside
diameter of hollow parts, you should:
a. pass current through it.
b. magnetize with a coil.
c. pass current through a central conductor.
d. increase the amperage used.
c. pass current through a central conductor.
49
52. What equipment is used to determine if a part has been demagnetized?
a. a magnet on the part
b. a field meter
c. a survey meter
d. careful observation for clinging magnetic particles
b. a field meter
50
Which of the following is most often used for dry magnetic particle inspection?
a. full cycle direct current
b. half wave rectified alternating direct current
c. high voltage, low amperage current
d. direct current from electrolytic cells
b. half-wave rectified alternating current
51
54. An electric current through a copper wire:
a. creates a magnetic field around the wire.
b. creates magnetic poles in the wire.
c. magnetizes the wire.
d. does not create a magnetic field.
a. creates a magnetic field around the wire.
52
55. Parts should be cleaned after demagnetization:
a. to ensure that the magnetic particles are
removed.
b. to prevent false indications.
c. to save the solids of the suspension.
d. to prevent cracking during heat treatment
a. to ensure that the magnetic particles are
removed.
53
56. In circular magnetization, the magnetizing force
is expressed in amperes. What term is used to
express magnetizing force in longitudinal
magnetization?
a. amperes
b. ampere-turns
c. consequent poles
d. volts
b. ampere-turns
54
57. A longitudinal surface crack in a circularly
magnetized part will cause:
a. the magnetic field to die out.
b. a decrease in permeability.
c. a magnetic leakage field.
d. a current to flow.
c. a magnetic leakage field.
55
58. In a magnetic particle test, assuming that all of
the following are in the same relative position in
a small part, which would be the hardest to
detect?
a. a surface crack
b. a near surface crack
c. a scratch
d. a seam
c. a scratch
56
59. If wet magnetic particle suspension is DQ1
uniform, then:
a. the strength of an indication may vary, and the
interpretation of the indication may be
erroneous.
b. the magnetic flux would not be uniform.
c. greater mobility would be required.
d. the part cannot be magnetized.
a. the strength of an indication may vary, and the
interpretation of the indication may be
erroneous.
57
60. Which of the following currents will best define
surface cracks?
a. half-wave rectified alternating current
b. direct current
c. alternating current
d. surge current
c. alternating current
58
61. When a magnetic field is induced in a part with
prods spaced 152 mm (6 in.) apart, the field is:
a. solenoidal.
b. circular.
c. longitudinal.
d. distorted trapezoidal.
b. circular.
59
62. Applying the theory of the right-hand rule, a
longitudinal surface defect in a round bar is
detected by “current passing in a direction
parallel to the direction of expected defects”
because:
a. the current direction is in line with the defect.
b. the magnetic field is at right angles to the
defect.
c. it makes no difference.
d. the magnetic field is parallel to the defect.
b. the magnetic field is at right angles to the
defect.
60
63. If a current is passed through an electrical
conductor, what will surround the conductor?
a. eddy current field
b. current
c. magnetic field
d. residual field
c. magnetic field
61
64. With current flowing from + to - in a coil, a
longitudinal field is created. Which of the
following may be used to establish the direction
of the magnetic field?
a. left-hand rule
b. right-hand rule
c. Ohm’slaw
d. Newton’s law
b. right-hand rule
62
65. When magnetic material is placed into a coil, the
magnetic lines of flux concentrate themselves in
the material and:
a. create a longitudinal magnetic field.
b. create a circular magnetic field.
c. create a longitudinal circular field.
d. have no effect
a. create a longitudinal magnetic field.
63
66. Which form of magnetization is easiest to detect
in most parts?
a. longitudinal magnetization
b. permanent magnetism
c. circular magnetization
d. parallel magnetization
a. longitudinal magnetization
64
67. The best type of magnetic field to use to inspect
a tubular product for surface defects along its
length is a:
a. longitudinal field.
b. circular field.
c. swinging field.
d. yoke magnetization.
b. circular field.
65
68. The area of maximum induced field strength
using a yoke is:
a. at the north pole of the yoke.
b. at the south pole of the yoke.
c. the area directly between the poles.
d. on the outside of pole pieces.
c. the area directly between the poles.
66
The strength of the magnetic field induced in a
part is often referred to as:
a. current density.
b. voltage.
c. flux density.
d. retentivity.
c. flux density.
67
70. A major factor that determines the success of
magnetic particle inspection is the:
a. field strength.
b. voltage on magnetizing coil.
c. current through the coil.
d. time of magnetization.
a. field strength.
68
71. What type of current is best suited to detect
surface discontinuities?
a. direct current
b. alternating current
c. pulsating direct current
d. half wave.
b. alternating current
69
73. One advantage of using fluorescent particles is:
a. that less equipment is required.
b. the high speed of inspection.
c. the cost.
d. that they are more readily attracted than other
particles.
b. the high speed of inspection.
70
72. When preparing a magnetic particle bath, it is
important to have the bath strength at a proper
level, as too many particles can result in:
a. lowering the test amperage.
b. having to increase the magnetizing current.
c. masking the indications.
d. none of the above.
c. masking the indications.
71
74. When using a dry magnetic particle powder, the
proper way to apply it to the part is to:
a. forcibly apply it with air.
b. roll the material in the container of powder.
c. apply it from the bottom of the part.
d. float the particles to inspection surface as
gently as possible.
d. float the particles to inspection surface as
gently as possible.
72
75. When using wet particles in water suspension,
wetting agents are added to:
a. prevent freezing.
b. prevent corrosion of inspection equipment.
c. ensure the proper wetting of the part.
d. decrease the amount of water needed.
c. ensure the proper wetting of the part.
73
76. When preparing an inspection bath, the amount
of magnetic particles per gallon of fluid is called
its:
a. measuring scale.
b. particle number.
c. strength or concentration.
d. usable limits.
c. strength or concentration.
74
77. Coercive force:
a. describes the means by which the magnetic
particles are suspended in the liquid when
using the wet method.
b. describes the magnetizing force used with the
continuous method.
c. represents the reverse magnetizing force
necessary to remove the residual magnetism in
a material.
d. is not a term used in magnetic particle testing.
c. represents the reverse magnetizing force
necessary to remove the residual magnetism in
a material.
75
78. Demagnetization:
a. may be accomplished by heating a material
above its curie point.
b. is always necessary.
c. can be performed only with alternating
current.
d. can be performed only with direct current.
a. may be accomplished by heating a material
above its curie point.
76
79. Resistance to demagnetization:
a. is greater in hard materials than soft materials.
b. is greater in soft materials than hard materials.
c. is the same for both hard and soft materials.
d. is nonexistent.
a. is greater in hard materials than soft materials.
77
80. Demagnetization:
a. may be easy or difficult depending on the type
of material.
b. is easy for materials having a high coercive
force.
c. is always most difficult in materials retaining
a high residual field.
d. All of the above answers are correct.
a. may be easy or difficult depending on the type
of material.
78
81. The strength of the wet suspension should be
maintained at a given level because:
a. a low level may give weak indications.
b. a high level may give heavy background.
c. both A and B.
d. none of the above.
c. both A and B.
79
82. Indications such as those at local external poles,
sharp fillets or thread roots are called:
a. fake indications.
b. relevant indications.
c. nonrelevant indications.
d. magnetic writing indications.
c. nonrelevant indications.
80
85. Which of the following statements is a
disadvantage of magnetic particle testing?
a. It can be used only on ferrous materials.
b. It can be applied only to detect surface
defects.
c. It can be applied only to detect subsurface
defects.
d. It can be applied to detect surface and
subsurface discontinuities in ferrous material.
a. It can be used only on ferrous materials.
81
83. Magnetic particle testing will reveal
discontinuities in which one of the following
materials?
a. bronze
b. carbon steel
c. aluminum castings
d. austenitic stainless steel
b. carbon steel
82
84. Magnetic particle testing is a nondestructive
testing method for detecting discontinuities in
magnetizable material. This method can detect:
a. surface discontinuities only.
b. subsurface discontinuities only.
c. surface and subsurface discontinuities.
d. discontinuities at surface and subsurface of
any depth.
c. surface and subsurface discontinuities.
83
86. Which one of following magnetic particles will
be most sensitive to small surface discontinuities
such as fatigue cracks?
a. dry powder
b. fluorescent particle
c. visible particle using oil as carrier (vehicle)
d. visible particle using water as carrier (vehicle)
b. fluorescent particle
84
87. Magnetic particles should have the:
a. highest possible retentivity.
b. lowest possible permeability.
c. highest possible permeability.
d. highest possible permeability and lowest
possible retentivity.
d. highest possible permeability and lowest
possible retentivity.
85
88. Nonrelevant indications can be caused by the
following, except:
a. excessive magnetizing current.
b. inadequate magnetizing current.
c. structural design of the test specimen.
d. variance of permeability within the test
specimen.
b. inadequate magnetizing current
86
89. A material with magnetic permeability less than
1 is known as:
a. diamagnetic.
b. paramagnetic.
c. ferromagnetic.
d. panamagnetic.
a. diamagnetic.
87
90. A small device, generally a metal strip or disk,
containing an artificial discontinuity used to
determine when the correct magnetizing
condition or magnetic field direction has been
achieved is:
a. an ohmmeter.
b. a gauss meter.
c. a flux indicator.
d. a field indicator.
C
88
91. The direction of magnetic line of force is __
degrees from the direction of current flow.
a. 45
b. 90
c. 180
d. 220
b. 90
