MT - MC

Question 1

Magnetic Particle is a non-destructive examination method used for?

a.) Locating surface discontinuities.
b.) Near surface (Sub Surface) discontinuities.
c.) Both a and b above.
d.) Material specification.

Answer 1

a.) Locating surface discontinuities.
b.) Near surface (Sub Surface) discontinuities.
c.) Both a and b above.

Question 2

Why are magnetic particles available in different colours?

a.) For colour contrast with the part surface.
b.) To enhance the detection of indications.
c.) For both a and b.
d.) Different colours are used with different magnetic flux values.

Answer 2

a.) For colour contrast with the part surface.
b.) To enhance the detection of indications.
c.) For both a and b.

Question 3

Which statement is true when related to Magnetic lines of force?

a.) They never cross.
b.) They are most dense at the poles of a magnet.
c.) They seek the path of least resistance.
d.) All of the above.

Answer 3

a.) They never cross.
b.) They are most dense at the poles of a magnet.
c.) They seek the path of least resistance.
d.) All of the above.

Question 4

When 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 dopier effect
d.) A high reluctance at the crack.

Answer 4

b.) A leakage field

Question 4

The magnetizing field is strongest when?

a.) The magnetizing voltage is flowing.
b.) The magnetizing current is flowing.
c.) The material exhibits high coercive fore.
d.) The magnetizing current is no flowing.

Answer 4

b.) The magnetizing current is flowing.

Question 5

Magnetic flux lines which are parallel to a discontinuity produces:

a.) Strong indications.
b.) Weak indications.
c.) No indications.
d.) Fuzzy indications.

Answer 5

c.) No indications.

Question 6

A circular field may be induced into a specimen by which of the following methods?

a.) Direct induction (Head Shot).
b.) Direct induction (Prods).
c.) Central conductors.
d.) All of the above.

Answer 6

a.) Direct induction (Head Shot).
b.) Direct induction (Prods).
c.) Central conductors.
d.) All of the above.

Question 7

An electrical yoke produces?

a.) A longitudinal field.
b.) A circular field.
c.) Alternating fields.
d.) A swinging field.

Answer 7

a.) A longitudinal field.

Question 8

A coil around the part produces?

a.) A circular field.
b.) A longitudinal field.
c.) Either a or b depending on the type of current applied.
d.) An intermittent field.

Answer 8

b.) A longitudinal field.

Question 9

A specimen may be demagnetized by which of the following methods?

a.) Heat treatment above Curie temperature.
b.) AC coil.
c.) Reversing DC fields.
d.) All of the above.

Answer 9

a.) Heat treatment above Curie temperature.
b.) AC coil.
c.) Reversing DC fields.
d.) All of the above.

Question 10

A metal that is difficult to magnetize is said to have?

a.) A high permeability.
b.) Low permeability.
c.) High reluctance.
d.) Low retentivity.

Answer 10

b.) Low permeability.

Question 11

Why is it preferable to disassemble parts before Magnetic Particle Inspection?

a.) Disassembly makes all surfaces areas visible.
b.) Interfaces wil create leakage fields which may confuse the inspection.
c.) It is usually easier to handle the disassembled parts.
d.) All of the above.

Answer 11

a.) Disassembly makes all surfaces areas visible.
b.) Interfaces wil create leakage fields which may confuse the inspection.
c.) It is usually easier to handle the disassembled parts.
d.) All of the above.

Question 12

Fluorescent Magnetic Particle indications should be inspected under?

a.) Fluorescent light.
b.) Any light.
c.) Black light.
d.) Neon light.

Answer 12

c.) Black light.

Question 13

A curve is sometimes drawn to show graphically the relation of the magnetizing force to the strength of the magnetic 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 13

b.) Hysteresis curve.

Question 14

What are the three causes of non-relevant indications?

a.) Lack of fusion, changes of section thickness, grinding cracks.
b.) Change of section thickness, very high amperage, and drilled hole near surface.
c.) Very high amperage, drilled holes near surface, blow holes.
d.) Drilled hole near surface, very high amperage, lack of fusion.

Answer 14

b.) Change of section thickness, very high amperage, and drilled hole near surface.

Question 15

A defect open to the surface produces an indication which is?

a.) Sharp and distinct.
b.) Wide and indefinite.
c.) Criss – Cross.
d.) High and fuzzy.

Answer 15

a.) Sharp and distinct.

Question 16

A metal that is difficult to magnetize is said to have?

a.) A high permeability.
b.) Low permeability.
c.) High reluctance.
d.) Low retentivity.

Answer 16

C. High reluctance

Question 17

The magnetism which remains in a piece of magnetizable material after the magnetizing force has been removed is called the?

a.) Tramp field.
b.) Residual field.
c.) Damped field.
d.) Permanent field.

Answer 17

b.) Residual field.

Question 18

What equipment is used to determine if a part has been demagnetized?

a.) A magnet on the part.
b.) Field meter.
c.) A survey meter.
d.) Carful observation for clinging magnetic particles.

Answer 18

b.) Field meter.

Question 19

Why should pats be cleaned after demagnetization?

a.) To assure 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 19

a.) To assure that the Magnetic Particles are removed.

Question 20

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 20

c.) Magnetic field.

Question 21

The 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 21

a.) Field strength.

Question 22

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 22

a.) The ease with which it can be magnetized.

Question 23

Which of the following can be tested by Magnetic Particle method?

a.) Iron.
b.) Nickel.
c.) Cobalt.
d.) All of the above.

Answer 23

a.) Iron.
b.) Nickel.
c.) Cobalt.
d.) All of the above.

Question 24

Ferromagnetic materials are?

a.) Strongly attracted by a magnet.
b.) Capable of being magnetized.
c.) Both a and b.
d.) Not capable of being magnetic.

Answer 24

a.) Strongly attracted by a magnet.
b.) Capable of being magnetized.
c.) Both a and b.

Question 25

Which of the following is an advantage of Magnetic Particle Testing over Penetrant Testing?

a.) It can detect surface discontinuities with foreign materials embedded in them.
b.) It is faster on individual parts.
c.) It can detect near-surface discontinuities.
d.) All of the above.

Answer 25

a.) It can detect surface discontinuities with foreign materials embedded in them.
b.) It is faster on individual parts.
c.) It can detect near-surface discontinuities.
d.) All of the above.

Question 26

When a magnetic field is induced in a part with prods spaced six inches apart, the field is?

a.) Solenoid.
b.) Circular.
c.) Longitudinal.
d.) Distorted trapezoidal.

Answer 26

b.) Circular.

Question 27

Magnetic Particle inspection reveals flaws by indicating?

a.) Leakage field.
b.) Flux residue.
c.) Hysteresis loop.
d.) Lines of force.

Answer 27

a.) Leakage field.

Question 27

To detect lengthwise defects 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 27

c.) Pass current through a central conductor.

Question 28

The areas of a magnetized part from which the magnetic field is leaving or resuming into the part are called?

a.) Salient points.
b.) Defects.
c.) Magnetic poles.
d.) Nodes.

Answer 28

c.) Magnetic poles.

Question 29

When there is absolutely no pattern or distribution of Magnetic Particles, the possible cause is that?

a.) The material is non-magnetic.
b.) The amperage setting is too low.
c.) No current is being applied.
d.) All of the above could be true.

Answer 29

a.) The material is non-magnetic.
b.) The amperage setting is too low.
c.) No current is being applied.
d.) All of the above could be true.

Question 30

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 30

c.) The area directly between the poles.

Question 31

Residual Magnetic Particle inspection may be used when?

a.) Parts are irregular in shape.
b.) Parts are highly retentive.
c.) Parts are high stressed.
d.) Evaluating continuous method indications.

Answer 31

b.) Parts are highly retentive.

Question 32

Magnetic Particle inspection is not a reliable method of detecting?

a.) Laps.
b.) Deep seated cavities.
c.) Cracks.
d.) Seams.

Answer 32

b.) Deep seated cavities.

Question 33

Sub-surface discontinuities indications usually appear?

a.) Sharp and distinct.
b.) Sharp and wide.
c.) Wide and fuzzy.
d.) High and loosely held.

Answer 33

c.) Wide and fuzzy.

Question 34

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 flow.

Answer 34

c.) A magnetic leakage field.

Question 35

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 powder.
c.) Apply it from the bottom of the part.
d.) Float eh particles to inspection surface as gently as possible.

Answer 35

d.) Float eh particles to inspection surface as gently as possible.

Question 36

Coercive force:

a.) Describes the means by which the Magnetic Particle 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 36

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

Question 37

Retentivity:

a.) Represents the ability to induce magnetism in a ferromagnetic body by an outside magnetizing force.
b.) Represents the ability of a material to resist the establishment of magnetic flux within it.
c.) Represents the ability of a material to retain a portion of the magnetic field set up in it after.

Answer 37

c.) Represents the ability of a material to retain a portion of the magnetic field set up in it after.