Level I Questions Magnetic Particle Testing Method

Question 1

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.

Answer 1

b. locating surface and near surface
discontinuities in steel.

Question 2

2. 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.

Answer 2

a. strongly attracted by a magnet.

Question 3

3. 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.

Answer 3

a. the ease with which it can be magnetized.

Question 4

4. 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.

Answer 4

d. the ability to retain the magnetic field.

Question 5

5. 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.

Answer 5

a. for color contrast with the part surface thereby
enhancing detection of indications.

Question 6

Which of the following can be magnetized?
a. iron
b. copper
c. aluminum
d. magnesium

Answer 6

a. iron

Question 7

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.

Answer 7

b. the magnetizing current is flowing.

Question 8

8. 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.

Answer 8

b. a leakage field.

Question 9

9. The unit usually used to denote flux density is:
   a. gauss.
   b. henry.
   c. farad.
   d. ampere.

Answer 9

a. gauss.

Question 10

10. 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.

Answer 10

b. They are most dense at the poles of a magnet.

Question 11

11. Magnetic flux lines that are parallel to a
    discontinuity produce:
    a. strong indications.
    b. weak indications.
    c. no indications.
    d. fuzzy indications.

Answer 11

c. no indications.

Question 12

12. 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.

Answer 12

b. the material is ferromagnetic.

Question 13

13. 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

Answer 13

b. right-hand rule

Question 14

14. 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.

Answer 14

b. the strength of the applied magnetizing force.

Question 15

15. 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.

Answer 15

a. its length and diameter.

Question 16

16. 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.

Answer 16

b. passing current directly through the part.

Question 17

17. An electrical yoke produces:
    a. a longitudinal field.
    b. a circular field.
    c. alternating fields.
    d. a swinging field.

Answer 17

a. a longitudinal field.

Question 18

18. 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.

Answer 18

b. a longitudinal field.

Question 19

19. In longitudinal magnetization the proper term for
    calculating magnetizing force is:
    a. amperes.
    b. ampere turns.
    c. watts.
    d. ohms.

Answer 19

b. ampere turns.

Question 20

20. Magnetic lines of force:
    a. travel in straight lines.
    b. form a closed loop.
    c. are randomly oriented.
    d. overlay in highly ferromagnetic materials.

Answer 20

b. form a closed loop.

Question 21

21. 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.

Answer 21

c. 90 degrees to the magnetic flux flow.

Question 22

22. 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.

Answer 22

c. Placing the part in reversing and decreasing
direct current fields.

Question 23

23. 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.

Answer 23

c. It can detect near-surface discontinuities.

Question 24

24. 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.

Answer 24

b. distance between the prods.

Question 25

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.

Answer 25

b. a magnetic field.

Question 26

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.

Answer 26

c. magnetic poles.

Question 27

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

Answer 27

b. low permeability.

Question 28

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.

Answer 28

b. residual magnetism.

Question 29

29. Subsurface discontinuity indications usually
    appear:
    a. sharp and distinct.
    b. sharp and wide.
    c. wide and fuzzy.
    d. high and loosely held.

Answer 29

c. wide and fuzzy.

Question 30

30. Which residual field is most difficult to demagnetize?
    a. longitudinal
    b. circular
    c. vector
    d. binodal

Answer 30

b. circular

Question 31

31. Which magnetic particle application technique is
    the most sensitive?
    a. continuous
    b. residual
    c. interrupted
    d. counter-current

Answer 31

a. continuous

Question 32

32. Fluorescent magnetic particle indications should
    be inspected under:
    a. any light.
    b. a neon light.
    c. an ultraviolet light.
    d. a fluorescent light.

Answer 32

c. an ultraviolet light.

Question 33

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.

Answer 33

c. residual method.

Question 34

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.

Answer 34

d. Dry continuous method using half-wave
rectified current with prods.

Question 35

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.

Answer 35

b. hysteresis curve.

Question 36

36. What method of applying particles provides
    greater sensitivity in locating subsurface weld
    discontinuities?
    a. continuous
    b. residual
    c. circular
    d. longitudinal

Answer 36

a. continuous

Question 37

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 operation.
    c. This is not a valid technique.
    d. There is no need to magnetize a weld in two
    directions.

Answer 37

a. The part should be checked to see if
demagnetization between operations is
necessary.

Question 38

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.

Answer 38

b. the amperage setting is too low.

Question 39

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

Answer 39

b. change of section thickness, heat affected
zones, drilled hole near surface

Question 40

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.

Answer 40

b. It may cause magnetic writing.

Question 41

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.

Answer 41

b. saturation point.

Question 42

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

Answer 42

a. alternating current

Question 43

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.

Answer 43

a. It may wash away a fine or weakly held
indication.

Question 44

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

Answer 44

b. parts are highly retentive.

Question 45

45. Magnetic particle inspection is not a reliable
    method of detecting:
    a. laps.
    b. deep internal cavities.
    c. cracks.
    d. seams.

Answer 45

b. deep internal cavities.

Question 46

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.

Answer 46

a. an ultraviolet light.

Question 47

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.

Answer 47

a. sharp and distinct.

Question 48

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

Answer 48

d. passing current through prods

Question 49

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.

Answer 49

b. immediately before applying the current.

Question 50

50. The strongest magnetic field in a coil is at the:
    a. outside edge.
    b. inside edge.
    c. center.
    d. end.

Answer 50

b. inside edge.

Question 51

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.

Answer 51

c. pass current through a central conductor.

Question 52

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

Answer 52

b. a field meter

Question 53

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

Answer 53

b. half-wave rectified alternating current

Question 54

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.

Answer 54

a. creates a magnetic field around the wire.

Question 55

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

Answer 55

a. to ensure that the magnetic particles are
removed.

Question 56

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

Answer 56

b. ampere-turns

Question 57

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.

Answer 57

c. a magnetic leakage field.

Question 58

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

Answer 58

c. a scratch

Question 59

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.

Answer 59

a. the strength of an indication may vary, and the
interpretation of the indication may be
erroneous.

Question 60

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

Answer 60

c. alternating current

Question 61

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.

Answer 61

b. circular.

Question 62

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.
    Ref: C.l9 and 15

Answer 62

b. the magnetic field is at right angles to the
defect.

Question 63

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

Answer 63

c. magnetic field

Question 64

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

Answer 64

b. right-hand rule

Question 65

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

Answer 65

a. create a longitudinal magnetic field.

Question 66

66. Which form of magnetization is easiest to detect
    in most parts?
    a. longitudinal magnetization
    b. permanent magnetism
    c. circular magnetization
    d. parallel magnetization

Answer 66

a. longitudinal magnetization

Question 67

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.

Answer 67

b. circular field.

Question 68

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.

Answer 68

c. the area directly between the poles.

Question 69

69. 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.

Answer 69

c. flux density.

Question 70

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.

Answer 70

a. field strength.

Question 71

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.

Answer 71

b. alternating current

Question 72

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.

Answer 72

c. masking the indications.

Question 73

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.

Answer 73

b. the high speed of inspection.

Question 74

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.

Answer 74

d. float the particles to inspection surface as
gently as possible.

Question 75

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.

Answer 75

c. ensure the proper wetting of the part.

Question 76

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.

Answer 76

c. strength or concentration.

Question 77

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.

Answer 77

c. represents the reverse magnetizing force
necessary to remove the residual magnetism in
a material.

Question 78

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.

Answer 78

a. may be accomplished by heating a material
above its curie point.

Question 79

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.

Answer 79

a. is greater in hard materials than soft materials.

Question 80

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.

Answer 80

a. may be easy or difficult depending on the type
of material.

Question 81

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.

Answer 81

c. both A and B.

Question 82

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.

Answer 82

c. nonrelevant indications.

Question 83

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

Answer 83

b. carbon steel

Question 84

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.

Answer 84

c. surface and subsurface discontinuities.

Question 85

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.

Answer 85

a. It can be used only on ferrous materials.

Question 86

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)

Answer 86

b. fluorescent particle

Question 87

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.

Answer 87

d. highest possible permeability and lowest
possible retentivity.

Question 88

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.

Answer 88

b. inadequate magnetizing current.

Question 89

89. A material with magnetic permeability less than
    1 is known as:
    a. diamagnetic.
    b. paramagnetic.
    c. ferromagnetic.
    d. panamagnetic.

Answer 89

a. diamagnetic.

Question 90

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.

Answer 90

c. a flux indicator.

Question 91

91. The direction of magnetic line of force is __
    degrees from the direction of current flow.
    a. 45
    b. 90
    c. 180
    d. 220

Answer 91

b. 90