ASNT Magnetic Particle Level III
Review Questions and Answers|100%
Correct|Guaranteed pass
Which of the following statements in not a valid reason for demagnetizing a part after
completing a magnetic particle test? - CORRECT ANSWER-if the part is to be
radiographed after magnetic particle inspection, residual magnetism may interfere with
the electromagnetic radiation spectrum
Subjecting a part to a magnetic field that is constantly reversing in polarity and gradually
diminishing in strength accomplishes which of the following? - CORRECT ANSWER-
demagnetizes the part
The concentration of the solid content in a suspension of magnetic particles is
measured by: - CORRECT ANSWER-permitting the solids to settle out of suspension
An important factor that must be considered when selecting a method of magnetization
is the: - CORRECT ANSWER-alloy, shape, and condition of the part
When a magnetic material reaches its curie temperature, the material becomes: -
CORRECT ANSWER-paramagnetic
Magnetic particle inspection methods on ferromagnetic materials are recognized as
superior to liquid penetrant techniques when: - CORRECT ANSWER-the parts are
painted
A paramagnetic material: - CORRECT ANSWER-is slightly magnetic
Which of the following will reduce a magnetic field? - CORRECT ANSWER-move the
alternating current coil farther away from the part
When an external magnetizing force is removed, some of the magnetic domains remain
preferentially oriented. The additional force required to return them to their original
random orientation is commonly referred to as: - CORRECT ANSWER-coercive force
When a cylinder is magnetized by a central conductor, the field is most intense: -
CORRECT ANSWER-at the inside surface of the cylinder
When is the magnetic field strongest in an object inspected by the magnetic particle
methods? - CORRECT ANSWER-while the magnetizing current is applied
, Which of the demagnetization methods listed is most effective? - CORRECT ANSWER-
direct current with alternating current with step-down control
When using the longitudinal magnetization method to inspect a bar 152 mm (6 in.) long
and 51 mm (2 in.) in diameter
with a 5-turn coil, which of the following amperage values should be used? - CORRECT
ANSWER-3000A
To examine a part 127 mm (5 in.) long and 51 mm (2 in.) in diameter using a 5-turn coil
and head stock magnetic
particle machine, what amperage should be used for longitudinal magnetization? -
CORRECT ANSWER-3600A
To examine a bar 381 mm (15in.) long and 51 mm (2 in.) in diameter using a 7-turn coil
and head-stock magnetic particle machine, what amperage should be used for circular
magnetization? - CORRECT ANSWER-1800 A
If the same amperage is passed through a 25 mm (1 in.) diameter bar and a 51 mm (2
in.) diameter bar of the same
length and material, the strength of the magnetic field at the surface: - CORRECT
ANSWER-of the 225mm (1 in.) bar will be approximately twice that of the 51 mm (2in.)
bar
If the same amperage is passed through a 25 mm (1 in.) diameter bar and a 51 mm (2
in.) diameter bar of the same
length and material, the strength of the magnetic field at the center of: - CORRECT
ANSWER-both bars will be 0
When a magnetic field is induced in a part with prods spaced 152 mm (6 in.) apart, the
field is a: - CORRECT ANSWER-circular field
When circular magnetization is used to detect subsurface discontinuities, direct current
is used instead of alternating current because: - CORRECT ANSWER-the skin effect of
alternating current reduces the maximum depth at which discontinuities can be found
An inspection method in which an initial magnetizing force is applied to a part and then
reduced to a lower continuous
value is called: - CORRECT ANSWER-the surge method
The magnetic domains in a permanent magnet are aligned: - CORRECT ANSWER-
fixed positions, predominantly in one direction
For which of the following would the wet fluorescent technique be preferred over the dry
technique? - CORRECT ANSWER-when increased speed and sensitivity are desired
Review Questions and Answers|100%
Correct|Guaranteed pass
Which of the following statements in not a valid reason for demagnetizing a part after
completing a magnetic particle test? - CORRECT ANSWER-if the part is to be
radiographed after magnetic particle inspection, residual magnetism may interfere with
the electromagnetic radiation spectrum
Subjecting a part to a magnetic field that is constantly reversing in polarity and gradually
diminishing in strength accomplishes which of the following? - CORRECT ANSWER-
demagnetizes the part
The concentration of the solid content in a suspension of magnetic particles is
measured by: - CORRECT ANSWER-permitting the solids to settle out of suspension
An important factor that must be considered when selecting a method of magnetization
is the: - CORRECT ANSWER-alloy, shape, and condition of the part
When a magnetic material reaches its curie temperature, the material becomes: -
CORRECT ANSWER-paramagnetic
Magnetic particle inspection methods on ferromagnetic materials are recognized as
superior to liquid penetrant techniques when: - CORRECT ANSWER-the parts are
painted
A paramagnetic material: - CORRECT ANSWER-is slightly magnetic
Which of the following will reduce a magnetic field? - CORRECT ANSWER-move the
alternating current coil farther away from the part
When an external magnetizing force is removed, some of the magnetic domains remain
preferentially oriented. The additional force required to return them to their original
random orientation is commonly referred to as: - CORRECT ANSWER-coercive force
When a cylinder is magnetized by a central conductor, the field is most intense: -
CORRECT ANSWER-at the inside surface of the cylinder
When is the magnetic field strongest in an object inspected by the magnetic particle
methods? - CORRECT ANSWER-while the magnetizing current is applied
, Which of the demagnetization methods listed is most effective? - CORRECT ANSWER-
direct current with alternating current with step-down control
When using the longitudinal magnetization method to inspect a bar 152 mm (6 in.) long
and 51 mm (2 in.) in diameter
with a 5-turn coil, which of the following amperage values should be used? - CORRECT
ANSWER-3000A
To examine a part 127 mm (5 in.) long and 51 mm (2 in.) in diameter using a 5-turn coil
and head stock magnetic
particle machine, what amperage should be used for longitudinal magnetization? -
CORRECT ANSWER-3600A
To examine a bar 381 mm (15in.) long and 51 mm (2 in.) in diameter using a 7-turn coil
and head-stock magnetic particle machine, what amperage should be used for circular
magnetization? - CORRECT ANSWER-1800 A
If the same amperage is passed through a 25 mm (1 in.) diameter bar and a 51 mm (2
in.) diameter bar of the same
length and material, the strength of the magnetic field at the surface: - CORRECT
ANSWER-of the 225mm (1 in.) bar will be approximately twice that of the 51 mm (2in.)
bar
If the same amperage is passed through a 25 mm (1 in.) diameter bar and a 51 mm (2
in.) diameter bar of the same
length and material, the strength of the magnetic field at the center of: - CORRECT
ANSWER-both bars will be 0
When a magnetic field is induced in a part with prods spaced 152 mm (6 in.) apart, the
field is a: - CORRECT ANSWER-circular field
When circular magnetization is used to detect subsurface discontinuities, direct current
is used instead of alternating current because: - CORRECT ANSWER-the skin effect of
alternating current reduces the maximum depth at which discontinuities can be found
An inspection method in which an initial magnetizing force is applied to a part and then
reduced to a lower continuous
value is called: - CORRECT ANSWER-the surge method
The magnetic domains in a permanent magnet are aligned: - CORRECT ANSWER-
fixed positions, predominantly in one direction
For which of the following would the wet fluorescent technique be preferred over the dry
technique? - CORRECT ANSWER-when increased speed and sensitivity are desired
