ASNT NDT Methods Exam Questions
With 100% Verified Correct Answers.
When the electrical current in an eddy current coil reverses direction the:
direction of the eddy currents in the test part also reverses.
In order to generate measurable eddy currents in a test specimen the specimen must be :
an electrical conductor.
The magnetic field generated by eddy currents induced in a test specimen:
opposes the magnetic field that induced the eddy current.
In eddy current testing, IACS is a recognized abbreviation for:
International Annealed Copper Standard
In eddy current testing, the specimen is coupled to the test coil by:
the coils electromagnetic fields.
The penetrations of eddy currents in a conductive material is decreased when the :
test frequency , conductivity of the specimen or permeability of the specimen is increased
At a fixed test frequency, in which of the following materials will the eddy
current penetration be greatest ?
Lead (7% IACS conductivity)
A term used to describe the effect observed due to a change in the coupling between a test
specimen and a flat probe coil when the distance of separation between them is varied is:
perpendicular to the major plane of the discontinuity
When testing with eddy currents, discontinuities will be most easily detected when the eddy
currents are:
perpendicular to the major plane of the discontinuity
,Which of the following discontinuities is easiest to detect with an eddy current test ? (
Assume that the area of the discontinuity is equal in all five choices listed):
a. A subsurface crack which lies parallel to the direction of the eddy current
b. A discontinuity located in the center of a 51 mm (2" ) diameter bar.
C. A radial crack that extends to the outer surface of a 51 mm ) 2 in. ) diameter bar.
d. A subsurface radial crack located at a depth of 13 mm (0.5 in.) in a 51 mm (2 in. )
diameter bar.
A term used to define the timing relationships involved in alternating current signals is :
impedance
The impedance of a test coil can be represented by the vector sum of :
inductive reactance and resistance.
Dis advantages of using a surface probe coil for the eddy current inspection of small-
diameter tubing include:
lift off variations effect.
The term " fill factor " applies to:
an encircling coil
Which of the following materials would be more likely used as a mounting material for
a probe coil ?
a. Aluminum
B. Plastic
c. copper
Nonferromagnetic steel Ferromagnetism is very important in industry and modern technology,
and is the basis for many electrical and electromechanical devices such as electromagnets,
electric motors, generators, transformers, and magnetic storage such as tape recorders, and
hard disks.
Which of the following is not a commonly used eddy current testing read-out mechanism ?
, A. Signal Generator
b. Meter c.Cathode
ray tube
d. Strip-chart recorder.
Reference Standards used for eddy current testing:
must be constructed from the same material of the object being inspected
Which of the following conditions is not important when selecting specimens to be used
as reference standards ?
If the material is aluminum the surface should be anodized.
Which of the following conditions would be the most difficult to detect when eddy current
testing a rod using a encircling coil
A small inclusion in the center of the rod.
The thickness of non conductive coatings on a conductive base can be most
simply measured by:
observing the lift off effect caused by the coating.
Some of the products commonly tested using encircling coils are :
rods, tubes and wire.
It is often possible to sort various alloys of a nonmagnetic metal by means of an
eddy current test when:
there is a unique range of conductivity values for each alloy
When conducting eddy current testing on tubing with a system that includes a
frequency discriminating circuit which of the following variables would be classified as a
high frequency variable ?
Small discontinuities
Which of the following is not a candidate for testing by the eddy current method :
With 100% Verified Correct Answers.
When the electrical current in an eddy current coil reverses direction the:
direction of the eddy currents in the test part also reverses.
In order to generate measurable eddy currents in a test specimen the specimen must be :
an electrical conductor.
The magnetic field generated by eddy currents induced in a test specimen:
opposes the magnetic field that induced the eddy current.
In eddy current testing, IACS is a recognized abbreviation for:
International Annealed Copper Standard
In eddy current testing, the specimen is coupled to the test coil by:
the coils electromagnetic fields.
The penetrations of eddy currents in a conductive material is decreased when the :
test frequency , conductivity of the specimen or permeability of the specimen is increased
At a fixed test frequency, in which of the following materials will the eddy
current penetration be greatest ?
Lead (7% IACS conductivity)
A term used to describe the effect observed due to a change in the coupling between a test
specimen and a flat probe coil when the distance of separation between them is varied is:
perpendicular to the major plane of the discontinuity
When testing with eddy currents, discontinuities will be most easily detected when the eddy
currents are:
perpendicular to the major plane of the discontinuity
,Which of the following discontinuities is easiest to detect with an eddy current test ? (
Assume that the area of the discontinuity is equal in all five choices listed):
a. A subsurface crack which lies parallel to the direction of the eddy current
b. A discontinuity located in the center of a 51 mm (2" ) diameter bar.
C. A radial crack that extends to the outer surface of a 51 mm ) 2 in. ) diameter bar.
d. A subsurface radial crack located at a depth of 13 mm (0.5 in.) in a 51 mm (2 in. )
diameter bar.
A term used to define the timing relationships involved in alternating current signals is :
impedance
The impedance of a test coil can be represented by the vector sum of :
inductive reactance and resistance.
Dis advantages of using a surface probe coil for the eddy current inspection of small-
diameter tubing include:
lift off variations effect.
The term " fill factor " applies to:
an encircling coil
Which of the following materials would be more likely used as a mounting material for
a probe coil ?
a. Aluminum
B. Plastic
c. copper
Nonferromagnetic steel Ferromagnetism is very important in industry and modern technology,
and is the basis for many electrical and electromechanical devices such as electromagnets,
electric motors, generators, transformers, and magnetic storage such as tape recorders, and
hard disks.
Which of the following is not a commonly used eddy current testing read-out mechanism ?
, A. Signal Generator
b. Meter c.Cathode
ray tube
d. Strip-chart recorder.
Reference Standards used for eddy current testing:
must be constructed from the same material of the object being inspected
Which of the following conditions is not important when selecting specimens to be used
as reference standards ?
If the material is aluminum the surface should be anodized.
Which of the following conditions would be the most difficult to detect when eddy current
testing a rod using a encircling coil
A small inclusion in the center of the rod.
The thickness of non conductive coatings on a conductive base can be most
simply measured by:
observing the lift off effect caused by the coating.
Some of the products commonly tested using encircling coils are :
rods, tubes and wire.
It is often possible to sort various alloys of a nonmagnetic metal by means of an
eddy current test when:
there is a unique range of conductivity values for each alloy
When conducting eddy current testing on tubing with a system that includes a
frequency discriminating circuit which of the following variables would be classified as a
high frequency variable ?
Small discontinuities
Which of the following is not a candidate for testing by the eddy current method :
