Level II Questions Magnetic Particle Testing Method

Question 1

1. The interpretation of magnetic particle
   indications may be aided by:

a. observing with a magnifying glass.
b. reproducing the indication after
demagnetization.
c. observing the indications after the part is
pre-cleaned.
d. observing the indications after the part is
post-cleaned.

Answer 1

a. observing with a magnifying glass.

Question 2

2. Residual magnetism may be beneficial as an aid:

a. in demagnetization.
b. in proper heat treating.
c. in the deposition of weld metal.
d. in interpretation and evaluation of indications

Answer 2

d. in interpretation and evaluation of indications

Question 3

3. An interruption in the normal physical structure
   or configuration of a part which produces a
   magnetic particle testing indication is called:

a. a defect.
b. an indication.
c. a deformation.
d. a discontinuity.

Answer 3

d. a discontinuity.

Question 4

4. Comparing parts that have been circularly
   magnetized and those that have been
   longitudinally magnetized, which retain the most
   objectionable residual field if not demagnetized?

a. circular
b. vectored
c. remnant
d. longitudinal

Answer 4

d. longitudinal

Question 5

5. What type of magnetization uses the formula:
   Ampere turns = 45 000/(L/D)?

a. circular
b. parallel
c. vectored
d. longitudinal

Answer 5

d. longitudinal

Question 6

6. Why are large soft contact pads such as lead or
   copper braid used for surfaces or headstocks?

a. To increase the contact area and reduce the
possibility of burning the part.
b. Because they help heat metal, thus facilitating
magnetic induction.
c. To increase the contact area and flux density.
d. Because of their low melting points.

Answer 6

a. To increase the contact area and reduce the
possibility of burning the part.

Question 7

7. A rough forging that has received no further
   processing is magnetic particle tested. An
   indication is observed to run in every direction
   and appears to extend deeply into the part and
   perpendicular to the surface. It is very sharp.
   What is the probable identity of the indication?

a. forging burst
b. flake
c. seam
d. lap

Answer 7

a. forging burst

Question 8

8. A gear with case-hardened ground teeth and hub
   ends is magnetic particle tested. Individual
   indications are detected on five teeth and one end
   surface of the hub. The indications do not break
   over the part edges. What is the probable identity
   of the indication?

a. grinding cracks
b. quench cracks
c. inclusions
d. porosity

Answer 8

a. grinding cracks

Question 9

9. If an overall pattern (sometimes circular lines)
   appears on the test surfaces, how should the
   inspector reprocess the test piece?

a. Demagnetize the piece.
b. Retest at a higher amperage.
c. Retest at lower amperage.
d. Part is not testable

Answer 9

c. Retest at lower amperage.

Question 10

10. A prime consideration when selecting a powder
    to be used as a magnetic particle medium is to
    select a powder that:

a. will adhere to the surface being tested.
b. provides a low contrast to the surface being
tested.
c. provides a high contrast to the surface being
tested.
d. quires a high demagnetization current to
remove it.

Answer 10

c. provides a high contrast to the surface being
tested.

Question 11

11. When testing for fine shallow surface cracks, the
    preferred magnetic particle test method should
    be:

a dry alternating current.
b. dry direct current.
c. wet alternating current.
d. wet direct current.

Answer 11

c. wet alternating current.

Question 12

12. Which of the following is an advantage of the
    dry method over the wet method?

a. It is more sensitive to fine surface cracks.
b. It is easier to use for field inspection with
portable equipment.
c. It is faster than the wet method when testing a
number of small parts.
d. It is more capable of providing full surface
coverage on irregularly shaped parts.

Answer 12

b. It is easier to use for field inspection with
portable equipment.

Question 13

13. When testing a bar with a length-to-diameter
    ratio of 4 in a 10-m coil, the required current
    would be:

a. 45 000A.
b. 18 000A.
c. 1125A.
d. Unknown, more information is needed.

Answer 13

c. 1125A.

Question 14

14. Internal splines and holes drilled parallel to, or
    near, test surfaces will cause:

a. sharp, well-defined indications directly
aligned with the part’s internal contours.
b. broad, fuzzy indications directly aligned with
the pan’s internal contours.
c. distinct indications not aligned with any
internal contours.
d. no indications.

Answer 14

b. broad, fuzzy indications directly aligned with
the pan’s internal contours.

Question 15

15. A limitation of coil magnetization techniques is
    that:

a. regardless of part size, the part cannot be
painted.
b. the coil must be of maximum diameter in
relation to part.
c. the effective field is generally limited on
either side of the coil.
d. small diameter parts must be placed close to
the center of the coil.

Answer 15

c. the effective field is generally limited on
either side of the coil.

Question 16

16. Which of the following wave patterns depicts the
    wave form of three-phase full-wave rectified
    alternating current?

Answer 16

a

Question 17

17. Which of the following casting discontinuities is
    caused by nonuniform cooling resulting in
    stresses that rupture the surface of the metal?

a. hot tears
h. porosity
c. dross
d. shrinkage

Answer 17

a. hot tears

Question 18

18. The term used to refer to the total opposition to
    flow of current represented by the combined
    effect of resistance, inductance and capacitance
    of a circuit is:

a. inductive reactance.
b. impedance.
c. reluctance.
d. decay.

Answer 18

b. impedance.

Question 19

19. A 3500 ampere-turn coil shot is required to be
    performed in a 5-turn coil after a head shot of
    800 A using the wet continuous method. In order
    to properly conduct the coil shot it is necessary
    to:

a. demagnetize the part between the head and
first coil shot.
b. check the part for residual magnetism with a
field indicator.
c. remove all residual wet magnetic particle fluid
from the part using clean, dry absorbent rags.
d. place the part in the coil and continue the
inspection after evaluating the head shot
indications.

Answer 19

d. place the part in the coil and continue the
inspection after evaluating the head shot
indications.

Question 20

20. When adding concentrate in paste form to any
    wet magnetic particle suspension liquid, it is
    common practice to:

a. add the paste directly to the suspension liquid.
b. change the entire bath after thoroughly
cleaning the system.
c. make a small, slurry-like test mixture of paste
and suspension and add directly to the bath.
d. mix paste in a small container with suspension
to the required bath strength and add directly
to the bath.

Answer 20

c. make a small, slurry-like test mixture of paste
and suspension and add directly to the bath.

Question 21

21. A desirable property of magnetic particles used
    for either the dry or wet method is that they:

a. be toxic.
b. be nonferromagnetic.
c. possess high retentivity.
d. possess high permeability.

Answer 21

d. possess high permeability.

Question 22

22. Which of the following can cause nonrelevant
    magnetic particle indications?

a. joints between dissimilar metals
b. thread cracks
c. scratches
d. bum

Answer 22

a. joints between dissimilar metals

Question 23

23. External poles which are too strong to permit
    good inspection of a part are more Likely to result
    when using:

a. longitudinal magnetization.
b. polarized magnetization.
c. residual magnetization.
d. circular magnetization.

Answer 23

a. longitudinal magnetization.

Question 24

24. A rough forging discontinuity has the following
    characteristics: can occur on surface or internally,
    is associated with low temperature processing, is
    often caused by excessive working and creates
    cavities varying in size. How would it be ‘
    identified?

a. pipe
b. burst
c. shrinkage
d. lamination

Answer 24

b. burst

Question 25

25. Discontinuities in plate, sheet or strip caused by
    internal fissures, inclusions or blowholes in the
    original ingot which, after rolling, are usually flat
    and parallel to the outside surface are called:

a. laps.
b. seams.
c. cracks.
d. laminations.

Answer 25

d. laminations.

Question 26

26. Forging laps occur in what relation to the axial
    direction of a part?

a. They are always found on thermal centerline.
b. They are found on the surface of a part at a
90-degree angle to the long axis.
c. They may occur anywhere in the part and
always run in the direction of working.
d. They may occur anywhere on the surface and
may bear no relation to the axial direction of
the part.

Answer 26

d. They may occur anywhere on the surface and
may bear no relation to the axial direction of
the part.

Question 27

27. The accumulation of particles at a site on the part
    surface, collected at and held to the site by the
    magnetic leakage field, is called:

a. a defect.
b. an indication.
c. a discontinuity.
d. magnetic writing.

Answer 27

b. an indication.

Question 28

28. Where particles are attracted to a site on the
    surface of a part by a magnetic leakage field that
    is caused by a condition such as a crack, lap, or
    other condition not acceptable to the applicable
    standards for the part, then we have:

a. a defect.
b. an indication.
c. a discontinuity.
d. a nonrelevant indication.

Answer 28

a. a defect.

Question 29

29. Half-wave rectified alternating current is used for
    detection of:

a. surface defects only.
b. subsurface defects only.
c. surface and subsurface defects when using dry
particles.
d. surface and subsurface defects when using wet
particles.

Answer 29

c. surface and subsurface defects when using dry
particles.

Question 30

30. Which of the following is an acceptable
    technique for removing a thin film of oil or
    grease prior to magnetic particle testing?

a. Wash with a solvent.
b. Degrease using a sand-blasting method.
c. Brush the surface with power wire brush.
d. Coat the surface with a thick layer of chalk
and then wipe with cloth

Answer 30

a. Wash with a solvent.

Question 31

31. Which of the following is the most common current method used for preserving and documenting
    magnetic particle indications?

a. hand drawn sketch
b. color-tinted tape
c. color-tinted lacquer
d. digital photography

Answer 31

d. digital photography

Question 32

32. Which of the following is not a discontinuity
    common to rolled products?

a. seams
b. cracks
c. cold shuts
d. laminations

Answer 32

c. cold shuts

Question 33

33. Which one of the following is not a discontinuity
    that can be produced by the forging process?

a. laps
b. bursts
c. flakes
d. shrinkage

Answer 33

d. shrinkage

Question 34

34. Which of the following is a discontinuity
    commonly associated with the welding process?

a. flakes
b. seams
c. laminations
d. lack of penetration

Answer 34

d. lack of penetration

Question 35

35. Which of these cracks may appear as an
    irregular, checked or scattered pattern of fine
    lines usually caused by local overheating?

a. corrosion
b. crater cracks
c. fatigue cracks
d. grinding cracks

Answer 35

d. grinding cracks

Question 36

36. Of the following discontinuity categories, which
    one is considered most detrimental to the service
    life of an item?

a. corrosion
b. subsurface inclusions
c. cracks open to the surface
d. subsurface porosity and voids

Answer 36

c. cracks open to the surface

Question 37

37. If a copper conductor is placed through a ferrous
    cylinder and a current is passed through the
    conductor, then the magnetic field (flux density)
    in the cylinder will be:

a. less than in the conductor.
b. greater than in the conductor.
c. the same intensity and pattern as in the
conductor.
d. the same regardless of its proximity to the
cylinder wall.

Answer 37

b. greater than in the conductor.

Question 38

38. The length of a part being magnetized by passing
    an electric current from one end to the other:

a. causes the magnetic field to vary.
b. affects the permeability of the part.
c. changes the strength of the magnetic field.
d. does not affect the strength of the magnetic
field.

Answer 38

d. does not affect the strength of the magnetic
field.

Question 39

39. If 25 mm (I in.) and 51 mm (2 in.) diameter bars
    of the same material were magnetized by passing
    the same current through them, the magnetic
    fields would be:

a. the same for both.
b. stronger in the 5 1 mm (2 in.) diameter bar.
c. weaker in the 25 mm (1 in.) diameter bar.
d. stronger in the 25 mm (1 in.) diameter bar.

Answer 39

d. stronger in the 25 mm (1 in.) diameter bar.

Question 40

40. If a current of the same amperage is passed through two conductors of the same dimensions, one of which is magnetic and one of which is nonmagnetic, the magnetic field distribution surrounding the conductors will:

a. vary with the permeability.
b. be the same for both conductors.
c. be stronger for the magnetic conductor.
d. be stronger for the nonmagnetic conductor

Answer 40

b. be the same for both conductors.

Question 41

41. The most effective magnetic particle test method
    for inspection of a large casting is using:

a. a tend conductor.
b. direct magnetization.
c. multidirectional magnetization.
d. prod inspection in two directions.

Answer 41

c. multidirectional magnetization.

Question 42

42. The most common failure mechanism associated
    with in-service parts with sharp fillets, notches,
    undercuts and seams is:

a. shrinkage.
b. crystallization.
c. Decarburization.
d. fatigue cracking.

Answer 42

d. fatigue cracking.

Question 43

43. When it is believed that a discontinuity has been removed by a grinding operation, the next operation is to:

a. repair it
b. sign off inspection of the part.
c. measure it to see if minimum thickness remains.
d. re-examine the area by magnetic particle testing.

Answer 43

d. re-examine the area by magnetic particle testing.

Question 44

When the most complete demagnetization available is desired and demagnetization is to be accomplished by placing the part in a coil energized with alternating current of progressively decreasing amperage, the following orientation of the long axis of the part is most desirable:

a. east-west.
b. north-east.
c. south-west.
d. north-south.

Answer 44

a. east-west.

Question 45

45. During a magnetic particle test, nonrelevant
    indications due to residual local poles are noted
    to be interfering with the magnetic particle
    testing. For a successful examination one should:

a use more amperage.
b. use lower amperage.
c. magnetize in another direction.
d. demagnetize then remagnetize in the desired
direction.

Answer 45

d. demagnetize then remagnetize in the desired
direction.

Question 46

46. Cold working indications will not reappear if the
    part is:

a. demagnetized then retested.
b. retested after stress relieving.
c. retested the opposite direction.
d. remagnetized at a higher amperage.

Answer 46

b. retested after stress relieving.

Question 47

47. The unit of measure of one line of flux per
    square centimeter of area is one:

a. ohm.
b. gauss.
c. ampere.
d. Oersted.

Answer 47

b. gauss.

Question 48

48. The ability of matter to attract other matter to
    itself is a phenomenon associated with:

a. magnetism.
b. field strength.
c. pole strength.
d. coercive force

Answer 48

a. magnetism.

Question 49

49. Materials which are strongly attracted to a magnet are called:

a. polarized.
b. magnetized.
c. nonmagnetic.
d. ferromagnetic

Answer 49

d. ferromagnetic

Question 50

50. Materials which are weakly attracted
    magnetically are called:

a. diamagnetic.
b. nonmagnetic.
c. paramagnetic.
d. ferromagnetic

Answer 50

c. paramagnetic.

Question 51

51. Materials which are repelled magnetically are called:

a. diamagnetic.
b. nonmagnetic.
c. paramagnetic.
d. ferromagnetic.

Answer 51

a. diamagnetic.

Question 52

52. The end of a magnet at which the lines of flux are thought of as entering the bar is the:

a. north pole.
b. south pole.
c. positive pole.
d. negative pole.

Answer 52

b. south pole.

Question 53

53. A general rule to use for determining the
    detectability of surface discontinuities by
    magnetic particle inspection is that:

a. the depth and width have no bearing to each
other.
b. the depth should be at a one-to-one ratio to the
width.
c. the depth should be 20% of the material
thickness.
d. the depth should be at least five times the
width of the opening of the discontinuity at
the surface.

Answer 53

d. the depth should be at least five times the
width of the opening of the discontinuity at
the surface.

Question 54

54. The general term used to refer to a break in the metallic continuity of the part being tested is:

a. discontinuity
b. crack.
C. seam.
d. lap

Answer 54

a. discontinuity

Question 55

55. The pattern of iron powder sprinkled on a paper
    placed over a bar magnet is called a:

a. flux meter.
b. field survey.
c. magnetometer.
d. magnetograph.

Answer 55

d. magnetograph.

Question 56

56. The lines of force that form a path around a crack in a ring magnet are called:

a. flux leakage
b. field strength
c. magnetic lines
d. longitudinal field

Answer 56

a. flux leakage

Question 57

57. Since the magnetic lines of force within a bar magnet run the length of the bar, it is said to be:

a. randomly magnetized.
b. circularly magnetized.
c. permanently magnetized.
d. longitudinally magnetized.

Answer 57

d. longitudinally magnetized.

Question 58

58. Lines of flux are thought to leave a magnet at
    the:

a. north pole.
b. south pole.
c. positive pole
d. negative pole.

Answer 58

a. north pole.

Question 59

59. A break in the magnetic uniformity of a part that
    is called a magnetic discontinuity is related to a
    sudden change in:

a. resistivity.
b. inductance.
c. permeability.
d. capacitance.

Answer 59

c. permeability.

Question 60

60. In order to detect defects in different directions in
    a material by magnetic particle inspection, it is
    best to use:

a. only one field.
b. other probe locations.
c. a high frequency field.
d. two or more fields in different directions

Answer 60

d. two or more fields in different directions

Question 61

61. The parts are blanks cut from rolled iron bar
    stock and have been rough machined. Inspection
    by continuous method reveals distinct but broken
    lines parallel (6.35 mm to 25 mm) (0.25 in. to
    1 in.) with the axis on some of the pieces. These
    indications are indicative of:

a. shrinkage.
b. nonmetallic inclusions.
c. surface checking.
d. machining tears.

Answer 61

b. nonmetallic inclusions.

Question 62

62. A large forging is repaired by welding. Magnetic particle inspection of the repair weld reveals a sharp irregular indication running parallel with
    the weld passes. It is located near the center of the bead and starts and ends by tuning off
    slightly from the axial direction. This indication
    is indicative of:

a. inclusions.
b. crater cracks.
c. surface checking.
d. weld shrinkage cracks.

Answer 62

d. weld shrinkage cracks.

Question 63

63. The wattage most commonly used for mercury
    vapor bulbs for portable fluorescent magnetic
    particle inspection is:

a. 50 watts
b. 75 watts
c. 100 watts
d. 200 watts

Answer 63

c. 100 watts

Question 64

64. An example of a nonelevant indication that would be classed as a magnetic discontinuity
    rather than an actual discontinuity could be
    caused by:

a corrosion.
b. a slag pocket.
c. grinding cracks.
d. a known abrupt change in the hardness of the Part.

Answer 64

d. a known abrupt change in the hardness of the Part.

Question 65

65. The detection of deep-lying internal defects in heavy steel weldments at a depth of 6.35 mm
    (0.25 in.) to 51 mm (2 in.) below surface is:

a. very improbable.
b. very similar to the detection of surface cracks.
c. simple if the defect’s width can be approximated.
d. not difficult if the defect is attributable to fine porosity.

Answer 65

a. very improbable.

Question 66

66. In magnetic particle inspection, it is best to:

a. make sure that parts meet specified acceptance
criteria.
b. reinspect all questionable discontinuities to
ensure that no defective parts are accepted.
c.reinspect questionable parts utilizing another
nondestructive test method.
d. make certain that parts are better than
specified and contain no discontinuities at all.

Answer 66

a. make sure that parts meet specified acceptance
criteria.

Question 67

67. Subjecting a magnetized object to a magnetic
    force that is continually reversing its direction
    and gradually decreasing in intensity is know as:

a. magnetization.
b. continuous method.
c. residual method.
d. demagnetization method.

Answer 67

d. demagnetization method.

Question 68

68. Any of these welding processes is susceptible to
    a discontinuity known as slag inclusion except:

a. flux cored arc welding
b. submerged arc welding
c: gas tungsten arc welding
d. shielded metal arc welding

Answer 68

c: gas tungsten arc welding

Question 69

69. Which of the following induces a longitudinal
    magnetic field?

a. prod
b. yoke
c. head shot
d. internal conductor

Answer 69

b. yoke

Question 70

70. At the curie point, steel is temporarily
    transformed from:

a. paramagnetic to diamagnetic.
b. ferromagnetic to diamagnetic.
c. paramagnetic to ferromagnetic.
d. ferromagnetic to paramagnetic.

Answer 70

d. ferromagnetic to paramagnetic.

Question 71

71. Magnetic field strength is measured in:

a. tesla.
b. gauss.
c. webers/m2
d. ampere/meter

Answer 71

d. ampere/meter

Question 72

72. The following types of discontinuities can be
    found in an object’s subsurface except:

a. pipe.
b. hot tears.
c. cold shut.
d. segregation

Answer 72

b. hot tears.

Question 73

73. Which one of following materials has
    permeability much greater than that of air?

a. permeability material
b. diamagnetic material
c. material
d. ferromagnetic material

Answer 73

d. ferromagnetic material

Question 74

74. As a magnet, the Earth is surrounded by
    magnetic lines of force. These lines of force
    make up what is sometimes called Earth field
    and they can cause problems in both magnetizing
    and demagnetizing. However Earth field is weak
    in the order of:

a. 0.3 gauss
b. 0.03 gauss
c. 0.003 gauss
d. 3.0 gauss

Answer 74

a. 0.3 gauss

Question 75

75. A hysteresis curve describes the relation
    between:

a. magnetizing force and flux density.
b. magnetizing force and applied current.
c. strength of magnetism and alignment of
domains within material.
d. magnetic flux density and current generated.

Answer 75

a. magnetizing force and flux density.

Question 76

Demagnetization would most likely be required when:

a. the material has low retentivity.
b. the object is to be electric arc welded.
c. the material has low reluctance.
d. heat treatment is to be carried out after testing.

Answer 76

b. the object is to be electric arc welded.

Question 77

77. One of the disadvantages of half-wave magnetization is, when demagnetizing:

a. the current has skin effect.
b. the current does not reverse.
c. the current passes very deep.
d. the current passes only on the surface.

Answer 77

b. the current does not reverse.

Question 78

78. One disadvantage of using a single-phase
    magnetic particle unit at current input values
    over 600 A, in comparison with a three-phase unit is, the single-phase unit will:

a. detect only surface discontinuities.
b. not detect subsurface discontinuities.
c. require 1.73 times more input current.
d. require 1.73 times less input current.

Answer 78

c. require 1.73 times more input current.

Question 79

79. In longitudinal magnetization of a round bar, residual magnetism will be:

a. greatest at the center of bar.
b. greatest at the ends of the bar.
c. the same all over on the bar.
d. the minimum at the ends.

Answer 79

b. greatest at the ends of the bar.

Question 80

80. Magnetic particles of varying size are used for dry powder and wet methods. Typically, particle sizes for wet method testing range from:

a. 1 to 5 micrometer.
b. 1 to 25 micrometer.
c. 100 to 500 micrometer.
d. 100 to 1000 micrometer.

Answer 80

b. 1 to 25 micrometer.

Question 81

81. Yokes of solid steel have been used for many years to indicate transverse cracks. Alternating current yokes are assembled from laminated
    transformer sheet to reduce:

a. the size of the yoke.
b. production costs.
c. the weight of the yoke.
d. eddy current losses.

Answer 81

d. eddy current losses.