UT-2 A Flashcards
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1
Q
- The wave mode that has multiple or varying wave velocities is:
a. longitudinal waves.
b. shear waves.
c. transverse waves.
d. lamb waves.
A
d. lamb waves.
2
Q
- Which of the following would be considered application(s) of ultrasonic techniques?
a. Determination of a material’s coefficient of expansion.
b. Study of a material’s metallurgical structure.
c. Determination of a material’s chemical composition.
d. Evaluation of surface tension through capillary action.
A
b. Study of a material’s metallurgical structure.
3
Q
- The only significant sound wave mode that travels through a liquid is a:
a. shear wave.
b. longitudinal wave.
c. surface wave.
d. rayleigh wave.
A
b. longitudinal wave.
4
Q
- The acoustic impedance of a material is used to determine the:
a. angle of refraction at an interface.
b. attenuation within the material.
c. relative amounts of sound energy coupled through and reflected at an interface.
d. beam spread within the material.
A
b. attenuation within the material.
5
Q
- When angle beam contact testing a test piece, increasing the incident angle until the second critical angle is reached may result in:
a. total reflection of a surface wave.
b. 45° refraction of the shear wave.
c. production of a surface wave.
d. a 90° angle of refraction for the wave.
A
c. production of a surface wave.
6
Q
- Acoustic energy propagates in different modes.
Which of the following represents a mode?
a. High-frequency ultrasonic waves.
b. A shear wave.
c. The dissipation factor.
d. The wave movement in the direction from the point where the energy was introduced.
A
b. A shear wave.
7
Q
- The simple experiment where a stick in a glass of water appears disjointed at the water surface illustrates the phenomenon of:
a. reflection.
b. magnification.
c. refraction.
d. diffraction.
A
c. refraction.
8
Q
- The crystal thickness and transducer frequency are related. The thinner the crystal:
a. the lower the frequency.
b. the higher the frequency.
c. there is no appreciable effect.
d. the lower the attenuation.
A
b. the higher the frequency.
9
Q
- The random distribution of crystallographic direction in alloys with large crystalline structures is a factor in determining:
a. the body-centered cubic crystal system.
b. the angle of refraction.
c. scattering of sound.
d. material thickness.
A
c. scattering of sound.
10
Q
- The length of the zone adjacent to a transducer in which fluctuations in sound pressure occur is mostly
affected by the:
a. frequency of the transducer.
b. the sound beam exit point.
c. length of transducer cable.
d. diameter of the transducer.
A
d. diameter of the transducer.
11
Q
- The differences in signals received from identical reflectors at different material distances from a transducer may be caused by:
a. material composition.
b. beam divergence.
c. acoustic impedance.
d. the piezoelectric effect.
A
b. beam divergence.
12
Q
- It is possible for a discontinuity smaller than the transducer to produce indications of fluctuating amplitude as the transducer is moved laterally if testing is being performed in the:
a. fraunhofer zone.
b. near field.
c. snell field.
d. shadow zone.
A
b. near field.
13
Q
- In immersion testing, the near-field effects of a transducer may be eliminated by:
a. increasing transducer frequency.
b. using a larger diameter transducer.
c. using an appropriate water path.
d. using a focused transducer.
A
c. using an appropriate water path.
14
Q
- In Figure 1, assuming a uniform beam pattern, what relationship would you expect to exist between the amplitudes of the reflected laminar signals at positions A and B?
a. 12 dB difference.
b. Equal amplitudes.
c. 2 to 1.
d. 3 to 1.
A
c. 2 to 1.
15
Q
- In the far field of a uniform ultrasonic beam, sound intensity is ____________ the beam centerline.
a. minimum at
b. maximum at
c. maximum throughout twice the angle where C is acoustic velocity, D is crystal diameter, and f is frequency at
d. not related to orientation of
A
b. maximum at
16
Q
- Which of the following may result in a long, narrow rod if the beam divergence results in a reflection from a side of the test piece before the sound wave reaches the back surface?
a. Multiple indications before the first back reflection.
b. Indications from multiple surface reflections.
c. Conversion from the longitudinal mode to shear
mode at the perimeter of the beam.
d. Loss of front-surface indications.
A
c. Conversion from the longitudinal mode to shear
mode at the perimeter of the beam.
17
Q
- Where does beam divergence occur?
a. Near field.
b. Far field.
c. At the crystal.
d. At the interface.
A
b. Far field.
18
Q
- As frequency increases in ultrasonic testing, the angle of beam divergence of a given diameter crystal:
a. decreases.
b. remains unchanged.
c. increases.
d. varies uniformly through each wavelength.
A
a. decreases.
19
Q
- As the radius of curvature of a curved lens is
increased, the focal length of the lens:
a. increases.
b. decreases.
c. remains the same.
d. cannot be determined unless the frequency is known.
A
a. increases.
20
Q
- When examining materials for planar flaws oriented parallel to the part surface, what testing method is most often used?
a. Angle beam.
b. Through-transmission.
c. Straight beam.
d. Dual crystal.
A
c. Straight beam.
21
Q
- If a contact angle beam transducer produces a 45° shear wave in steel, the angle produced by the same transducer in an aluminum specimen would be: (Vsteel = 0.323 cm/μs; VA L = 0.310 cm/μs)
a. less than 45°.
b. greater than 45°.
c. 45°.
d. unknown; more information is required.
A
a. less than 45°.
22
Q
- Rayleigh waves are influenced most by discontinuities located:
a. close to or on the surface.
b. 1 wavelength below the surface.
c. 3 wavelengths below the surface.
d. 6 wavelengths below the surface.
A
a. close to or on the surface.
23
Q
- The ultrasonic testing technique in which finger
damping is most effective in locating a discontinuity is the:
a. shear wave technique.
b. longitudinal wave technique.
c. surface wave technique.
d. compressional wave technique.
A
c. surface wave technique.
24
Q
- Lamb waves can be used to detect:
a. laminar-type discontinuities near the surface of a thin material.
b. lack of fusion in the center of a thick weldment.
c. internal voids in diffusion bonds.
d. thickness changes in heavy plate material.
A
a. laminar-type discontinuities near the surface of a
thin material.
25
Q
- The ratio of the velocity of sound in water compared to that for aluminum or steel is approximately:
a. 1:8.
b. 1:4.
c. 1:3.
d. 1:2.
A
b. 1:4.
26
Q
- Which of the following scanning methods could be
classified as an immersion-type test?
a. Contact angle beam testing.
b. Surface wave technique with a plastic transducer
wedge.
c. Scanning with a wheel-type transducer with the
transducer inside a liquid-filled tire.
d. Through-transmission technique with shear
waves.
A
c. Scanning with a wheel-type transducer with the
transducer inside a liquid-filled tire.
27
Q
- In an immersion test of a piece of steel or aluminum, the water distance appears on the display as a fairly wide space between the initial pulse and the
front-surface reflection because of:
a. reduced velocity of sound in water as compared
to the test specimen.
b. increased velocity of sound in water as compared
to the test specimen.
c. temperature of the water.
d. viscosity of the water.
A
a. reduced velocity of sound in water as compared
28
Q
- Using the immersion method, a distance-amplitude
curve (DAC) for a 19 mm (0.75 in.) diameter, 5 MHz
transducer shows the high point of the DAC at the
B/51 mm (2 in.) block. One day later, the high point
of the DAC for the same transducer is at the
J/102 mm (4 in.) block. Assuming that calibration has not changed, this would indicate that the transducer:
a. is improving in resolution.
b. is becoming defective.
c. has the beam of a contact testing transducer.
d. has a better definition.
A
b. is becoming defective.
29
Q
- What law can be used to calculate the angle of
refraction within a metal for both longitudinal and
shear waves?
a. Poisson’s ratio law.
b. Snell’s law.
c. Fresnel’s field law.
d. Charles’ law.
A
b. Snell’s law.
30
Q
- At an interface between two different materials, an
impedance difference results in:
a. reflection of the entire incident energy at the
interface.
b. absorption of sound.
c. division of sound energy into transmitted and
reflected modes.
d. refraction of the entire incident energy at the
interface.
A
c. division of sound energy into transmitted and
reflected modes.
31
Q
- When using focused transducers, nonsymmetry in a propagated sound beam may be caused by:
a. backing material variations.
b. mode conversion.
c. diffraction characteristics.
d. irregular sound beam exit point.
A
a. backing material variations.
32
Q
- Ultrasonic wheel units may be used for which of the following types of examination?
a. Contact testing of aluminum plates.
b. Through-transmission testing of impeller shafts.
c. Longitudinal wave and/or shear wave examination.
d. Angle beam testing on beam-to-column T-joint
complete penetration welds.
A
c. Longitudinal wave and/or shear wave examination.
33
Q
- During straight beam testing, test specimens with nonparallel front and back surfaces can cause:
a. partial or total loss of back reflection.
b. no loss in back reflection.
c. a widened (broad) back-reflection indication.
d. a focused (narrow) back-reflection indication.
A
a. partial or total loss of back reflection.
34
Q
- In the immersion technique, the distance between the face of the transducer and the test surface (water path) is usually adjusted so that the time required to send the sound beam through the water is:
a. equal to the time required for the sound to travel through the test piece.
b. greater than the time required for the sound to
travel through the test piece.
c. less than the time required for the sound to travel through the test piece.
d. greater or less than the time required for the
sound to travel through the test piece depending
on water temperature and wave characteristics.
A
b. greater than the time required for the sound to
travel through the test piece.
35
Q
- In a B-scan display, the length of a screen indication from a discontinuity is related to:
a. a discontinuity’s thickness as measured parallel to the ultrasonic beam.
b. the discontinuity’s length in the direction of the
transducer travel.
c. the horizontal baseline elapsed time from left to
right.
d. the vertical and horizontal directions representing the area over which the transducer was scanned.
A
b. the discontinuity’s length in the direction of the
transducer travel.
36
Q
- Which circuit triggers the pulser and sweep circuits in an A-scan display?
a. Receiver-amplifier.
b. Power supply.
c. Clock.
d. Damping.
A
c. Clock.
37
Q
- On an A-scan display, the dead zone, refers to the:
a. distance contained within the near field.
b. area outside the beam spread.
c. distance covered by the front-surface pulse width
and recovery time.
d. area between the near field and the far field.
A
c. distance covered by the front-surface pulse width
and recovery time.
38
Q
- On an A-scan display, what represents the intensity of a reflected beam?
a. Echo pulse width.
b. Horizontal screen location.
c. Signal brightness.
d. Signal amplitude.
A
d. Signal amplitude.
39
Q
- Of the following scan types, which one can be used to produce a recording of discontinuitiy areas superimposed over a plan view of the test piece?
a. A-scan.
b. B-scan.
c. C-scan.
d. D-scan.
A
c. C-scan.
40
Q
- In immersion testing in a small tank, a manually operated manipulator is used to:
a. manipulate the pulser/receiver unit and the display.
b. set the proper transducer angle.
c. set the proper index function.
d. set the proper bridge distance.
A
b. set the proper transducer angle.
41
Q
- In straight (normal) beam contact testing, which of the following would NOT result in a reduction in the back-surface reflection amplitude?
a. the usage of a high-viscosity couplant.
b. a discontinuity that is normal to the beam.
c. a near-surface discontinuity that cannot be
resolved from the main bang (initial pulse).
d. a coarse-grain material.
A
a. the usage of a high-viscosity couplant.
42
Q
- A 152 mm (6 in.) diameter rod is being inspected for centerline cracks. The A-scan presentation for one complete path through the rod is as shown in Figure
- The alarm gate should:
a. be used between points A and E.
b. be used at point D only.
c. be used between points B and D.
d. not be used for this application.
A
c. be used between points B and D.
43
Q
- In an automatic scanning immersion unit, the bridge or carriage serves to:
a. support the manipulator and scanner tube and to
move it about transversely and longitudinally.
b. control the angular and transverse positioning of
the scanner tu be.
c. control the vertical and angular positioning of the
scanner tube.
d. raise and lower the transducer.
A
a. support the manipulator and scanner tube and to
move it about transversely and longitudinally.
44
Q
- When adjusting the discontinuity-locating rule for a shear wave weld inspection, the zero point on the rule must coincide with the:
a. sound beam exit point of the wedge.
b. point directly over the discontinuity.
c. wheel transducer.
d. circular scanner.
A
a. sound beam exit point of the wedge.
45
Q
- A special scanning device with the transducer
mounted in a tire-like container filled with couplant
is commonly called:
a. a rotating scanner.
b. an axial scanner.
c. a wheel transducer.
d. a circular scanner.
A
c. a wheel transducer.
46
Q
- Which best describes a typical display of a crack whose major surface is perpendicular to the ultrasonic beam?
a. A broad indication.
b. A sharp indication.
c. The indication will not show due to improper orientation.
d. A broad indication with high amplitude.
A
b. A sharp indication.
47
Q
- A primary purpose of a reference standard is to:
a. provide a guide for adjusting instrument controls
to reveal discontinuities that are considered
harmful to the end use of the product.
b. give the technician a tool for determining exact
discontinuity size.
c. provide assurance that all discontinuities smaller
than a certain specified reference reflector are
capable of being detected by the test.
d. provide a standard reflector, which exactly
simulates natural discontinuities of a critical size.
A
a. provide a guide for adjusting instrument controls
to reveal discontinuities that are considered
harmful to the end use of the product.
48
Q
- Compensation for the variation in echo height related to variations in discontinuity depth in the test material is known as:
a. transfer.
b. attenuation.
c. distance-amplitude correction.
d. interpretation.
A
c. distance-amplitude correction.
49
Q
- Which of the following is a reference reflector that is not dependent on beam angle?
a. A flat-bottom hole.
b. A V-notch.
c. A side-drilled hole which is parallel to the plate
surface and perpendicular to the sound path.
d. A disk-shaped laminar reflector.
A
c. A side-drilled hole which is parallel to the plate
50
Q
- During a straight beam ultrasonic test, a
discontinuity indication is detected that is small in
amplitude compared to the loss in amplitude of back reflection. The orientation of this discontinuity is probably:
a. parallel to the test surface.
b. perpendicular to the sound beam.
c. parallel to the sound beam.
d. at an angle to the test surface.
A
d. at an angle to the test surface.
51
Q
- A discontinuity is located having an orientation such
that its long axis is parallel to the sound beam. The
indication from such a discontinuity will be:
a. large in proportion to the length of the
discontinuity.
b. small in proportion to the length of the
discontinuity.
c. representative of the length of the discontinuity.
d. such that complete loss of back reflection will
result.
A
b. small in proportion to the length of the
discontinuity.
52
Q
- Gas discontinuities are reduced to flat disks or other shapes parallel to the surface by:
a. rolling.
b. machining.
c. casting.
d. welding.
A
a. rolling.
53
Q
- In which zone does the amplitude of an indication
from a given discontinuity diminish exponentially as
the distance increases?
a. Far-field zone.
b. Near-field zone.
c. Dead zone.
d. Fresnel zone.
A
a. Far-field zone.
54
Q
- A smooth, flat discontinuity whose major plane is not perpendicular to the direction of sound propagation may be indicated by:
a. an echo amplitude comparable in magnitude to
the back-surface reflection, as well as complete
loss of the back-surface reflection.
b. an echo whose amplitude is steady across the
discontinuity surface.
c. an increase in backwall with no response from
discontinuity.
d. the absence of an indication.
A
a. an echo amplitude comparable in magnitude to
the back-surface reflection, as well as complete
loss of the back-surface reflection.
55
Q
- Using a pulse echo technique, if the major plane of a flat discontinuity is oriented at some angle other than
perpendicular to the direction of sound propagation,
the result may be:
a. loss of signal linearity.
b. loss or lack of a received discontinuity echo.
c. focusing of the sound beam.
d. loss of interference phenomena.
A
b. loss or lack of a received discontinuity echo.
56
Q
- As transducer diameter decreases, the beam spread:
a. decreases.
b. remains the same.
c. increases.
d. becomes conical in shape.
A
c. increases.
57
Q
- A set of standard reference blocks with the same
geometrical configuration and dimensions other than
the size of the calibration reflectors, for example,
flat-bottom holes, is called a set of:
a. distance-amplitude standards.
b. area-amplitude standards.
c. variable frequency blocks.
d. beam spread measuring blocks.
A
b. area-amplitude standards.
58
Q
- The angle at which 90° refraction of a longitudinal
sound wave is reached is called the:
a. angle of incidence.
b. first critical angle.
c. angle of maximum reflection.
d. second critical angle.
A
b. first critical angle.
59
Q
- The control of voltage supplied to the vertical
deflection plates of the instrument display in an
A-scan UT setup is performed by the:
a. sweep generator.
b. pulser.
c. amplifier circuit.
d. clock timer.
A
c. amplifier circuit.
60
Q
- Attenuation is a difficult quantity to measure
accurately, particularly in solid materials, at the test
frequencies normally used. The overall result usually
observed includes other loss mechanisms, such as:
a. temperature.
b. scan rate.
c. fine grain structure.
d. beam spread.
A
d. beam spread.
61
Q
- The most commonly used method of producing
shear waves in a flat test part when inspecting by the
immersion method is by:
a. transmitting longitudinal waves into a part in a
direction perpendicular to its front surface.
b. using two crystals vibrating at different
frequencies.
c. angulating the search tube or manipulator to the
proper angle.
d. using Y-cut quartz crystal.
A
c. angulating the search tube or manipulator to the
proper angle.
62
Q
- Large grains in a metallic test specimen usually result in:
a. scatter, which becomes less pronounced as grain
size approaches wavelength.
b. increased penetration.
c. have no effect if a higher frequency is used.
d. large grass or hash or noise indications.
A
d. large grass or hash or noise indications.
63
Q
- The total energy losses occurring in all materials is
called:
a. attenuation.
b. scatter.
c. beam spread.
d. interface.
A
a. attenuation.
64
Q
- Delay-tip (stand-off) type contact transducers are
primarily used for:
a. discontinuity detection.
b. sound wave characterization.
c. thickness measurement or discontinuity detection
in thin materials.
d. attenuation measurements.
A
c. thickness measurement or discontinuity detection
in thin materials.
65
Q
- Acoustical lenses are commonly used for contour
correction. When scanning the inside of a pipe
section by the immersion method, use a:
a. focused cup lens.
b. convex lens.
c. concave lens.
d. variable pitch lens.
A
b. convex lens.
66
Q
- In Figure 3, transducer A is being used to establish:
a. verification of wedge angle.
b. sensitivity calibration.
c. resolution.
d. an index point.
A
d. an index point.
67
Q
- In Figure 3, transducer C is being used to check:
a. distance calibration.
b. resolution.
c. sensitivity calibration.
d. verification of wedge angle
A
c. sensitivity calibration.
68
Q
- In Figure 3, transducer D is being used to check:
a. sensitivity calibration.
b. distance calibration.
c. resolution.
d. verification of wedge angle.
A
d. verification of wedge angle.
69
Q
- When the incident angle is chosen to be between the first and second critical angles, the ultrasonic wave
generated within the part will be:
a. longitudinal.
b. shear.
c. surface.
d. lamb.
A
b. shear.
70
Q
- In Figure 4, transducer B is being used to check:
a. the verification of wedge angle.
b. resolution.
c. sensitivity calibration.
d. distance calibration.
A
b. resolution.
71
Q
- The angle at which 90° refraction of the shear wave
mode occurs is called the:
a. first critical angle.
b. second critical angle.
c. third critical angle.
d. angle of reflection.
A
b. second critical angle.
72
Q
- In a water immersion test, ultrasonic energy is
transmitted into steel at an incident angle of 14°.
What is the angle of the refracted shear wave within
the material?
Vs = 3.2 x 10^5 cm/s
Vw = 1.5 x 10^5 cm/s
(Trigonometry Tables Required)
a. 45°
b. 23°
c. 31°
d. 13°
A
c. 31°
73
Q
- If you were requested to design a plastic shoe to
generate a rayleigh wave in aluminum, what would
be the incident angle of the ultrasonic energy?
VA = 3.1 x 10^5 cm/s
Vp = 2.6 x 10^5 cm/s
(Trigonometry Tables Required)
a. 37°
b. 57°
c. 75°
d. 48°
A
b. 57°
74
Q
- Compute the wavelength of ultrasonic energy in lead at 1 MHz.
VL = 2.1 x 10^5 cm/s
V = λ x F
a. 0.21 cm
b. 21 cm
c. 0.48 cm
d. 4.8 x 10^5 cm
A
a. 0.21 cm
75
Q
- For aluminum and steel, the longitudinal velocity is
approximately _________ the shear velocity.
a. equal to
b. twice
c. half of
d. four times
A
b. twice
76
Q
- Water travel distance for immersion inspections
should be:
a. such that the second front reflection does not
appear between the first front and back reflections.
b. exactly 76 mm (3 in.).
c. less than 76 mm (3 in.).
d. always equal to the thickness of the material
being inspected.
A
a. such that the second front reflection does not
appear between the first front and back reflections.
77
Q
- The electronic circuitry that allows selection and processing of only those signals relating to
discontinuities that occur in specific zones of a part
is called:
a. an electronic gate.
b. an electronic attenuator.
c. a distance amplitude correction circuit.
d. a fixed marker.
A
a. an electronic gate.
78
Q
- When conducting a contact ultrasonic test, the grass or irregular signals that appear in the screen display of the area being inspected could be caused by:
a. fine grains in the structure.
b. dirt in the water couplant.
c. coarse grains in the structure.
d. a thick but tapered back surface.
A
c. coarse grains in the structure.
79
Q
- In inspecting a 102 mm (4 in.) diameter threaded steel cylinder for radial cracks extending from the root of the threads, it would be preferable to transmit:
a. shear waves at an angle to the threads.
b. longitudinal waves from the end of the cylinder
and perpendicular to the direction of the thread
roots.
c. surface waves perpendicular to the thread roots.
d. shear waves around the circumference of the
cylinder.
A
b. longitudinal waves from the end of the cylinder
and perpendicular to the direction of the thread
roots.
80
Q
- In an immersion inspection of raw steel material, the water travel distance should be:
a. exactly 76 mm (3 in.).
b. equal to 76 mm (3 in.) ±13 mm (±0.5 in.).
c. greater than one-fourth the thickness of the part.
d. equal to the thickness of a material.
A
c. greater than one-fourth the thickness of the part.
81
Q
- The angle formed by an ultrasonic wave as it enters
a medium of different velocity than the one from
which it came and a line drawn perpendicular to the
interface between the two media is called the angle of:
a. incidence.
b. refraction.
c. rarefaction.
d. reflection.
A
b. refraction.
82
Q
- The process of adjusting an instrument or device to a reference standard is referred to as:
a. angulation.
b. scanning.
c. correcting for distance-amplitude variations.
d. calibration.
A
d. calibration.
83
Q
- A grouping of a number of crystals in one transducer, with all contact surfaces in the same plane and vibrating in phase with each other to act as a single
transducer is called a:
a. focusing crystal.
b. crystal mosaic.
c. scrubber.
d. single-plane manipulator.
A
b. crystal mosaic.
84
Q
- The angle of reflection is:
a. equal to the angle of incidence.
b. dependent on the couplant used.
c. dependent on the frequency used.
d. equal to the angle of refraction.
A
a. equal to the angle of incidence.
85
Q
- The angular position of the reflecting surface of a
planar discontinuity with respect to the entry surface
is referred to as:
a. the angle of incidence.
b. the angle of refraction.
c. the orientation of the discontinuity.
d. angle of reflection.
A
c. the orientation of the discontinuity.
86
Q
- A short burst of alternating electrical energy is called:
a. a continuous wave.
b. a peaked DC voltage.
c. an ultrasonic wave.
d. a pulse.
A
d. a pulse.
87
Q
- In ultrasonic testing, the time duration of the
transmitted pulse is referred to as the:
a. pulse length or pulse width.
b. pulse amplitude.
c. pulse shape.
d. pulse distortion.
A
a. pulse length or pulse width.
88
Q
- The phenomenon by which a wave strikes a
boundary and changes the direction of its
propagation within the same medium is referred to
as:
a. divergence.
b. impedance.
c. angulation.
d. reflection.
A
d. reflection.
89
Q
- The change in direction of an ultrasonic beam when
it passes from one medium to another whose velocity
differs from that of the first medium is called:
a. refraction.
b. rarefaction.
c. angulation.
d. reflection.
A
a. refraction.
90
Q
- Which of the following modes of vibration exhibits
the shortest wavelength at a given frequency and in a
given material?
a. A longitudinal wave.
b. A compression wave.
c. A shear wave.
d. A surface wave.
A
d. A surface wave.
91
Q
- In general, shear waves are more sensitive to small
discontinuities than longitudinal waves for a given
frequency and in a given material because:
a. the wavelength of shear waves is shorter than the
wavelength of longitudinal waves.
b. shear waves are not as easily dispersed in the
material.
c. the direction of particle vibration for shear waves
is more sensitive to discontinuities.
d. the wavelength of shear waves is longer than the
wavelength of longitudinal waves.
A
a. the wavelength of shear waves is shorter than the
wavelength of longitudinal waves.
92
Q
- In general, which of the following modes of vibration would have the greatest penetrating power in a coarse-grained material if the frequency of the waves
is the same?
a. Longitudinal waves.
b. Shear waves.
c. Transverse waves.
d. Rayleigh waves.
A
a. Longitudinal waves.
93
Q
- A testing technique in which the crystal or
transducer is parallel to the test surface and
ultrasonic waves enter the material being tested in a
direction perpendicular to the test surface is:
a. straight beam testing.
b. angle beam testing.
c. surface wave testing.
d. lamb wave.
A
a. straight beam testing.
94
Q
- The distance from a given point on an ultrasonic
wave to the next corresponding point is referred
to as:
a. frequency.
b. wavelength.
c. velocity.
d. pulse length.
A
b. wavelength.
95
Q
- The speed with which ultrasonic waves travel
through a material is known as:
a. velocity.
b. pulse repetition rate.
c. pulse recovery rate.
d. ultrasonic response.
A
a. velocity.
96
Q
- A substance that reduces the surface tension of a
liquid is referred to as:
a. a couplant.
b. an ultrasonic dampener.
c. a wetting agent.
d. a solvent.
A
c. a wetting agent.
97
Q
- The ultrasonic transducers most commonly used for discontinuity testing utilize:
a. magnetostriction principles.
b. piezoelectric principles.
c. mode conversion principles.
d. relative dialectric principles.
A
b. piezoelectric principles.
98
Q
- Mechanical and electrical stability, insolubility in
liquids, and resistance to aging are three advantages
of transducers made of:
a. lithium sulfate.
b. barium titanate.
c. quartz.
d. rochelle salts.
A
c. quartz.
99
Q
- The sin Ɵ1/V1 = sin Ɵ2/V2 formula is referred to as:
a. the acoustical impedance ratio formula.
b. the phase conversion formula.
c. the fresnel zone formula.
d. Snell’s law.
A
d. Snell’s law.
100
Q
- The sin Ɵ1/V1 = sin Ɵ2/V2 formula is used to determine:
a. angular relationships.
b. phase velocities.
c. amount of reflected sound energy.
d. acoustic impedance.
A
a. angular relationships.
101
Q
- The amount of energy reflected from a discontinuity is not dependent on the:
a. size of the discontinuity.
b. orientation of the discontinuity.
c. type of discontinuity.
d. filter setting.
A
d. filter setting.
102
Q
- If an ultrasonic wave is transmitted through an
interface of two materials in which the first material
has a higher acoustic impedance value but the same
velocity value as the second material, the angle of
refraction will be:
a. greater than the angle of incidence.
b. less than the angle of incidence.
c. the same as the angle of incidence.
d. beyond the critical angle.
A
c. the same as the angle of incidence.
103
Q
- Which one of the following frequencies would
probably result in the greatest ultrasonic attenuation
losses?
a. 1 MHz
b. 2.25 MHz
c. 10 MHz
d. 25 MHz
A
d. 25 MHz
104
Q
- The product of the sound velocity and the density of
a material is known as the:
a. refraction value of the material.
b. acoustic impedance of the material.
c. elastic constant of the material.
d. Poisson’s ratio of the material.
A
b. acoustic impedance of the material.
105
Q
- The amplifier range over which the unsaturated
signal response increases in amplitude in proportion
to the discontinuity surface area is the:
a. sensitivity range.
b. vertical linearity range.
c. selectivity range.
d. horizontal linearity range.
A
b. vertical linearity range.
106
Q
- What kind of waves travel at a velocity slightly less
than shear waves and their mode of propagation is
both longitudinal and transverse with respect to the
surface?
a. Rayleigh waves.
b. Transverse waves.
c. L-waves.
d. Longitudinal waves.
A
a. Rayleigh waves.
107
Q
- Which ultrasonic test frequency would probably
provide the best penetration in a 30 cm (12 in.) thick
specimen of coarse-grained steel?
a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz
A
a. 1 MHz
108
Q
- During immersion testing of an ASTM Ultrasonic
Standard Reference Block, a B-scan presentation
system will show a:
a. plan view of the block, showing the area and
position of the hole bottom as seen from the
entry surface.
b. basic test pattern showing the height of an
indication from the hold bottom and its location
in depth from the entry surface.
c. cross section of the reference block, showing the
top and bottom surfaces of the block and the
location of the hole bottom in the block.
d. cross-sectional view presentation with a vertical
signal representing the hole bottom and the
horizontal position representing its depth
position.
A
c. cross section of the reference block, showing the
top and bottom surfaces of the block and the
location of the hole bottom in the block.
109
Q
- Properties of shear or transverse waves used for
ultrasonic testing include:
a. particle motion normal to propagation direction,
and a propagation velocity that is about one-half
the longitudinal wave velocity in the same
material.
b. exceptionally high sensitivity due to low
attenuation resulting from longer wavelengths
when propagating through water.
c. high coupling efficiency because shear waves are
less sensitive to surface variables when traveling
from a coupling liquid to the part.
d. high sensitivity as a result of having a greater
wave velocity than longitudinal waves in the same
material.
A
a. particle motion normal to propagation direction,
and a propagation velocity that is about one-half
the longitudinal wave velocity in the same
material.
110
Q
- One of the most common applications of ultrasonic
tests employing shear waves is for the:
a. detection of discontinuities in welds,
tube and pipe.
b. determination of elastic properties of
metallic products.
c. detection of laminar discontinuities in
heavy plate.
d. measurement of thickness of thin plate.
A
a. detection of discontinuities in welds,
tube and pipe.
111
Q
- Significant errors in ultrasonic thickness
measurement can occur if:
a. the test frequency is varying at a constant rate.
b. the velocity of propagation deviates substantially
from an assumed constant value for a given
material.
c. water is employed as a couplant between the
transducer and the part being measured.
d. the echo-to-echo mode is used.
A
b. the velocity of propagation deviates substantially
from an assumed constant value for a given
material.
112
Q
- Generally, the best ultrasonic testing method for
detecting discontinuities oriented along the fusion
zone in a welded plate is:
a. an angle beam contact method using surface
waves.
b. a contact test using a straight longitudinal wave.
c. an immersion test using surface waves.
d. an angle beam method using shear waves.
A
d. an angle beam method using shear waves.
113
Q
- An ultrasonic testing instrument that displays pulses
representing the magnitude of reflected ultrasound as
a function of time or depth of metal is said to
contain:
a. a continuous wave.
b. an A-scan presentation.
c. a B-scan presentation.
d. a C-scan presentation.
A
b. an A-scan presentation
114
Q
- At a water-steel interface, the angle of incidence in
water is 7°. The principal mode of vibration that
exists in the steel is:
a. longitudinal.
b. shear.
c. lamb.
d. surface.
A
a. longitudinal.
115
Q
- In a liquid medium, the only mode of vibration that
can exist is:
a. longitudinal.
b. shear.
c. lamb.
d. surface.
A
a. longitudinal.
116
Q
- In an ultrasonic instrument, the number of pulses
produced by an instrument in a given period of time
is known as the:
a. pulse length of the instrument.
b. pulse recovery time.
c. frequency.
d. pulse repetition frequency.
A
d. pulse repetition frequency.
117
Q
- In a basic pulse echo ultrasonic instrument, the
component that coordinates the action and timing of
other components is called a:
a. display unit.
b. receiver.
c. marker circuit or range marker circuit.
d. timing section.
A
d. timing section.
118
Q
- In a basic pulse echo ultrasonic instrument, the
component that produces the voltage that activates
the transducer is called:
a. an amplifier.
b. a receiver.
c. a pulser.
d. a synchronizer
A
c. a pulser.
119
Q
- In a basic pulse echo ultrasonic instrument, the
component that produces the time baseline is called
a:
a. sweep circuit.
b. receiver.
c. pulser.
d. synchronizer.
A
a. sweep circuit.
120
Q
- In a basic pulse echo ultrasonic instrument, the
component that produces visible signals on the
screen which are used to measure distance is called a:
a. sweep circuit.
b. marker circuit.
c. receiver circuit.
d. synchronizer.
A
b. marker circuit.
121
Q
- Most basic pulse echo ultrasonic instruments use:
a. automatic readout equipment.
b. an A-scan presentation.
c. a B-scan presentation.
d. a C-scan presentation.
A
b. an A-scan presentation.
122
Q
- The instrument displays a plan view of the part
outline and discontinuities when using:
a. automatic readout equipment.
b. an A-scan presentation.
c. a B-scan presentation.
d. a C-scan presentation.
A
d. a C-scan presentation.
123
Q
- The incident angles at which 90° refraction of
longitudinal and shear waves occurs are called the:
a. normal angles of incidence.
b. critical angles.
c. angles of maximum reflection.
d. mode angles.
A
b. critical angles.
124
Q
- Compression waves whose particle displacement is
parallel to the direction of propagation are called:
a. longitudinal waves.
b. shear waves.
c. lamb waves.
d. rayleigh waves.
A
a. longitudinal waves.
125
Q
- The mode of vibration that is quickly damped out
when testing by the immersion method is:
a. longitudinal waves.
b. shear waves.
c. transverse waves.
d. surface waves.
A
d. surface waves.
126
Q
- The motion of particles in a shear wave is:
a. parallel to the direction of propagation of the
ultrasonic beam.
b. transverse to the direction of beam propagation.
c. limited to the material surface and elliptical in
motion.
d. polarized in a plane at 45° to the direction of
beam propagation.
A
b. transverse to the direction of beam propagation.
127
Q
- An ultrasonic longitudinal wave travels in aluminum
with a velocity of 635 000 cm/s and has a frequency
of 1 MHz. The wavelength of this ultrasonic wave is:
a. 6.35 mm (0.25 in.).
b. 78 mm (3.1 in.).
c. 1.9 m (6.35 ft).
d. 30 000 A.
A
a. 6.35 mm (0.25 in.).
128
Q
- The refraction angle of longitudinal ultrasonic waves
passing from water into a metallic material at angles
other than normal to the interface is primarily a
function of the:
a. impedance ratio (r = ZwZM) of water to metal.
b. relative velocities of sound in water and metal.
c. frequency of the ultrasonic beam.
d. density ratio of water to metal.
A
b. relative velocities of sound in water and metal.
129
Q
- In contact testing, shear waves can be induced in the test material by:
a. placing an X-cut crystal directly on the surface of
the materials and coupling through a film of oil.
b. using two transducers on opposite sides of the
test specimen.
c. placing a spherical acoustic lens on the face of the
transducer.
d. using a transducer mounted on a plastic wedge so
that sound enters the part at an angle.
A
d. using a transducer mounted on a plastic wedge so
that sound enters the part at an angle.
130
Q
- As frequency increases in ultrasonic testing, the angle of beam divergence of a given diameter crystal:
a. decreases.
b. remains unchanged.
c. increases.
d. varies uniformly through each wavelength.
A
a. decreases.
131
Q
- Which of the following is not an advantage of contact ultrasonic transducers (probes) adapted with plastic shoes?
a. Most of the crystal wear is eliminated.
b. Adaptation to curved surfaces is permitted.
c. Sensitivity is increased.
d. Ultrasound is allowed to enter a part’s surface at
oblique angles.
A
c. Sensitivity is increased.
132
Q
- The velocity of sound is the lowest in:
a. air.
b. water.
c. aluminum.
d. plastic.
A
a. air.
133
Q
- A longitudinal ultrasonic wave is transmitted from
water into steel at an angle of 5° from the normal.
In such a case, the refracted angle of the transverse
wave is:
a. less than the refracted angle of the longitudinal wave.
b. equal to the refracted angle of the longitudinal wave.
c. greater than the refracted angle of the longitudinal wave.
d. not present at all.
A
a. less than the refracted angle of the longitudinal wave.
134
Q
- The velocity of longitudinal waves is the highest in:
a. water.
b. air.
c. aluminum.
d. plastic.
A
c. aluminum.
135
Q
- In steel, the velocity of sound is greatest in:
a. longitudinal waves.
b. shear waves.
c. surface waves.
d. lamb waves.
A
a. longitudinal waves.
136
Q
- The acoustic impedance is:
a. used to calculate the angle of reflection.
b. the product of the density of the material and the
velocity of sound in the material.
c. found by Snell’s law.
d. used to determine resonance values.
A
b. the product of the density of the material and the
velocity of sound in the material.
137
Q
- Thin sheet may be inspected with the ultrasonic wave directed normal to the surface by observing the:
a. amplitude of the front-surface reflection.
b. multiple reflection pattern.
c. attenuation rate.
d. ratio of shear and longitudinal velocities.
A
b. multiple reflection pattern.
138
Q
- A diagram in which the entire circuit stage or
sections are shown by geometric figures and the path
of the signal or energy by lines and/or arrows is
called a:
a. schematic diagram.
b. blueprint.
c. block diagram.
d. circuit layout.
A
c. block diagram.
139
Q
- A void caused by gas entrapped in a casting is called:
a. a burst.
b. a cold shut.
c. flaking.
d. a blowhole.
A
d. a blowhole.
140
Q
- A discontinuity that occurs during the casting of
molten metal which may be caused by the splashing,
surging, interrupted pouring, or the meeting of two
streams of metal coming from different directions is
called:
a. a burst.
b. a cold shut.
c. flaking.
d. a blowhole.
A
b. a cold shut.
141
Q
- The ratio between the wave speed in one material
and the wave speed in a second material is called:
a. the acoustic impedance of the interface.
b. Young’s modulus.
c. Poisson’s ratio.
d. refractive index.
A
d. refractive index.
142
Q
- The expansion and contraction of a magnetic
material under the influence of a changing magnetic
field is referred to as:
a. piezoelectricity.
b. refraction.
c. magnetostriction.
d. rarefaction.
A
c. magnetostriction.
143
Q
- The ratio of stress to strain in a material within the
elastic limit is called:
a. Young’s modulus.
b. the impedance ratio.
c. Poisson’s ratio.
d. refractive index.
A
a. Young’s modulus.
144
Q
- When setting up for an ultrasonic inspection, the
pulse repetition rate of the instrument must be:
a. low enough so that transmitted waves will not
interfere with reflected signals.
b. immaterial as the pulse repetition rate does not
affect the ability to detect indications regardless of
size.
c. slow enough to allow the instrument display to
refresh with each pulse.
d. fast enough for the operator to be able to rely on
the discontinuity alarm instead of constantly
watching the screen.
A
a. low enough so that transmitted waves will not
interfere with reflected signals.
145
Q
- The factor that determines the amount of reflection
at the interface of two dissimilar materials is:
a. the index of rarefaction.
b. the frequency of the ultrasonic wave.
c. Young’s modulus.
d. the acoustic impedance.
A
d. the acoustic impedance.
146
Q
- A quartz crystal cut so that its major faces are parallel to the Z and Y axes and perpendicular to the X axis is called:
a. a Y-cut crystal.
b. an X-cut crystal.
c. a Z-cut crystal.
d. a ZY-cut crystal.
A
b. an X-cut crystal.
147
Q
- The equation describing wavelength in terms of
velocity and frequency is:
a. wavelength = velocity x frequency.
b. wavelength = z (frequency x velocity).
c. wavelength = velocity / frequency.
d. wavelength = frequency + velocity
A
c. wavelength = velocity / frequency.
148
Q
- When an ultrasonic beam reaches the interface of
two dissimilar materials, it can be:
a. 100% reflected.
b. 100% absorbed.
c. partially reflected and refracted, but not absorbed.
d. partially reflected, refracted, and transmitted.
A
d. partially reflected, refracted, and transmitted.
149
Q
- When inspecting aluminum by the immersion
method using water for a couplant, the following
information is known:
velocity of sound in water = 1.49 x 10s cm/s,
velocity of longitudinal waves in aluminum =
6.32 x 10s cm/s, and angle of incidence = 5°.
The angle of refraction for longitudinal waves is
approximately:
a. 22°
b. 18°
c. 26°
d. 16°
A
a. 22°
150
Q
- Of the piezoelectric materials listed below, the most
efficient sound transmitter is:
a. lithium sulfate.
b. quartz.
c. barium titanate.
d. silver oxide.
A
c. barium titanate.
151
Q
- Of the piezoelectric materials listed below, the most
efficient sound receiver is:
a. lithium sulfate.
b. quartz.
c. barium titanate.
d. silver oxide.
A
a. lithium sulfate.
152
Q
- The most commonly used method of producing
shear waves in a test part when inspecting by the
immersion method is by:
a. transmitting longitudinal waves into a part in a
direction perpendicular to its front surface.
b. using two crystals vibrating at different
frequencies.
c. using a Y-cut quartz crystal.
d. angulating the search tube to the proper angle.
A
d. angulating the search tube to the proper angle.
153
Q
- Beam divergence is a function of the dimensions of
the crystal and the wavelength of the beam
transmitted through a medium, and it:
a. increases if the frequency or crystal diameter
decreases.
b. decreases if the frequency or crystal diameter
decreases.
c. increases if the frequency increases and crystal
diameter decreases.
d. decreases if the frequency increases and crystal
diameter decreases.
A
a. increases if the frequency or crystal diameter
decreases.
154
Q
- The wavelength of an ultrasonic wave is:
a. directly proportional to velocity and frequency.
b. directly proportional to velocity and inversely
proportional to frequency.
c. inversely proportional to velocity and directly
proportional to frequency.
d. equal to the product of velocity and frequency.
A
b. directly proportional to velocity and inversely
proportional to frequency.
155
Q
- The fundamental frequency of a piezoelectric crystal
is primarily a function of the:
a. length of the applied voltage pulse.
b. amplifying characteristics of the pulse amplifier in
the instrument.
c. thickness of the crystal.
d. material testing.
A
c. thickness of the crystal.
156
Q
- Acoustic velocities of materials are primarily due to
the material’s:
a. density and elasticity.
b. material thickness.
c. temperature.
d. acoustic impedance.
A
a. density and elasticity.
157
Q
- Inspection of castings is often impractical because of:
a. extremely small grain structure.
b. coarse grain structure.
c. uniform flow lines.
d. uniform velocity of sound.
A
b. coarse grain structure.
158
Q
- Lamb waves may be used to inspect:
a. forgings.
b. bar stock.
c. ingots.
d. thin sheet.
A
d. thin sheet.
159
Q
- The formula used to determine the angle of beam
divergence of a quartz crystal is:
a. sinƟ = diameter r 1/2 x wavelength.
b. sinƟ diameter = frequency x wavelength.
c. sin Ɵ = frequency x wavelength.
d. sin Ɵ/2 = 1.22 x wavelength/diameter.
A
d. sin Ɵ/2 = 1.22 x wavelength/diameter.
160
Q
- The resolving power of a transducer is directly
proportional to its:
a. diameter.
b. bandwidth.
c. pulse repetition.
d. Poisson’s ratio.
A
b. bandwidth.
161
Q
- Acoustic lens elements with which of the following
permit focusing the sound energy to enter cylindrical
surfaces normally or along a line focus?
a. Cylindrical curvatures.
b. Spherical lens curvatures.
c. Convex shapes.
d. Concave shapes.
A
a. Cylindrical curvatures.
162
Q
- In the basic pulse echo instrument, the synchronizer, clock or timer circuit determines the:
a. pulse length.
b. gain.
c. pulse repetition rate.
d. sweep length.
A
c. pulse repetition rate.
163
Q
- The primary requirement of a paintbrush transducer is that:
a. all crystals be mounted equidistant from each
other.
b. the intensity of the beam pattern not vary greatly
over the entire length of the transducer.
c. the fundamental frequency of the crystals not
vary more than 0.01%.
d. the overall length not exceed 76 mm (3 in.).
A
b. the intensity of the beam pattern not vary greatly
over the entire length of the transducer.
164
Q
- Heat conduction, viscous friction, elastic hysteresis,
and scattering are four different mechanisms that
lead to:
a. attenuation.
b. refraction.
c. beam spreading.
d. saturation.
A
a. attenuation.
165
Q
- Because the velocity of sound in aluminum is
approximately 245 000 in./s, for sound to travel
through 25 mm (1 in.) of aluminum, it takes:
a. 1/8 s
b. 4 μs
c. 4 ms
d. 1/4 xl04 s
A
b. 4 μs
166
Q
- When testing a part with a rough surface, it is
generally advisable to use a:
a. lower frequency transducer and a more viscous
couplant than is used on parts with a smooth
surface.
b. higher frequency transducer and a more viscous
couplant than is used on parts with a smooth
surface.
c. higher frequency transducer and a less viscous
couplant than is used on parts with a smooth
surface.
d. lower frequency transducer and a less viscous
couplant than is used on parts with a smooth
surface.
A
a. lower frequency transducer and a more viscous
couplant than is used on parts with a smooth
surface.
167
Q
- Reflection indications from a weld area being
inspected by the angle beam technique may
represent:
a. porosity.
b. backwall.
c. initial pulse.
d. hot tears.
A
a. porosity.
168
Q
- During a test using A-scan equipment, strong
indications that move at varying rates across the
screen in the horizontal direction appear. It is
impossible to repeat a particular screen pattern by
scanning the same area. A possible cause of these
indications is:
a. porosity in the test part.
b. an irregularly shaped crack.
c. a blowhole.
d. electrical interference.
A
d. electrical interference.
169
Q
- In an A-scan presentation, position along the
horizontal baseline indicates:
a. a square wave pattern.
b. a sweep line.
c. a marker pattern.
d. elapsed time.
A
d. elapsed time.
170
Q
- The greatest amount of attenuation losses take place at:
a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz
A
d. 10 MHz
171
Q
- Waves that travel around gradual curves with little or no reflection from the curve are called:
a. transverse waves.
b. surface waves.
c. shear waves.
d. longitudinal waves.
A
b. surface waves.
172
Q
- To evaluate and accurately locate discontinuities after scanning a part with a paintbrush transducer, it is
generally necessary to use a:
a. transducer with a smaller crystal.
b. scrubber.
c. grid map.
d. crystal collimator.
A
a. transducer with a smaller crystal.
173
Q
- An ultrasonic instrument has been calibrated to
obtain an 80% FSH indication from a 2 mm (0.08 in.)
diameter flat-bottom hole located 76 mm (3 in.) from
the front surface of an aluminum reference block.
When testing an aluminum forging, an 80% FSH
indication is obtained from a discontinuity located
76 mm (3 in.) from the entry surface. The reflective
area of this discontinuity is probably:
a. the same as the area of the 2 mm (0.08 in.)
flat-bottom hole.
b. greater than the area of the 2 mm (0.08 in.)
flat-bottom hole.
c. slightly less than the area of the 2 mm (0.08 in.)
flat-bottom hole.
d. about one-half the area of the 2 mm (0.08 in.)
flat-bottom hole.
A
b. greater than the area of the 2 mm (0.08 in.)
flat-bottom hole.
174
Q
- As the impedance ratio of two dissimilar materials
increases, the percentage of sound coupled through
an interface of such materials:
a. decreases.
b. increases.
c. is not changed.
d. may increase or decrease.
A
a. decreases.
175
Q
- Lower frequency sound waves are not generally used for pulse echo testing of thinner materials because of:
a. the rapid attenuation of low frequency sound.
b. incompatible wavelengths.
c. poor near-surface resolution.
d. fraunhofer field effects.
A
c. poor near-surface resolution.
176
Q
- In immersion testing, the accessory equipment to
which the search cable and the transducer are
attached is called a:
a. crystal collimator.
b. scrubber.
c. jet-stream unit.
d. search tube or scanning tube.
A
d. search tube or scanning tube.
177
Q
- In general, discontinuities in wrought products tend
to be oriented:
a. randomly.
b. in the direction of grain flow.
c. at right angles to the entry surface.
d. at right angles to the grain flow.
A
b. in the direction of grain flow.
178
Q
- In immersion testing of round bars, the back surface
contour may result in:
a. loss of back reflection.
b. additional indications following the direct back
surface reflection.
c. inability to distinguish the actual distance to the
back-surface reflection.
d. false indications of discontinuities near the back
surface.
A
a. loss of back reflection.
179
Q
- In contact testing, discontinuities near the entry
surface cannot always be detected because of:
a. the far-field effect.
b. attenuation.
c. the dead zone.
d. refraction.
A
c. the dead zone.
180
Q
- In cases where the diameter of tubing being inspected is smaller than the diameter of the transducer, what can be used to confine the sound beam to the proper range of angles?
a. A scrubber.
b. A collimator.
c. An angle plane angulator.
d. A jet-stream unit
A
b. A collimator.
181
Q
- Which of the following is more likely to limit the
maximum scanning speed in immersion testing?
a. The frequency of the transducer.
b. Viscous drag problems.
c. The pulse repetition rate of the test instrument.
d. The persistency of the ultrasonic instrument
display.
A
c. The pulse repetition rate of the test instrument.
182
Q
- The property of certain materials to transform
electrical energy to mechanical energy and vice versa
is called:
a. mode conversion.
b. piezoelectric effect.
c. refraction.
d. impedance matching.
A
b. piezoelectric effect.
183
Q
- Surface waves energy levels are concentrated at what depth below the surface?
a. 25 mm (1 in.).
b. 102 mm (4 in.).
c. 1 wavelength.
d. 4 wavelengths.
A
c. 1 wavelength.
184
Q
- To prevent the appearance of the second front surface indication before the first back reflection when
inspecting aluminum by the immersion method
(water is used as a couplant), it is necessary to have a
minimum of at least 25 mm ( l in.) of water for every
of aluminum.
a. 51 mm (2 in.)
b. 102 mm (4 in.)
c. 152 mm (6 in.)
d. 203 mm (8 in.)
A
b. 102 mm (4 in.)
185
Q
- Increasing the length of the pulse used to activate the transducer will:
a. increase the strength of the ultrasound but
decrease the resolving power of the instrument.
b. increase the resolving power of the instrument.
c. have no effect on the test.
d. decrease the penetration of the sound wave.
A
a. increase the strength of the ultrasound but
decrease the resolving power of the instrument.
186
Q
- The lack of parallelism between the entry surface and the back surface:
a. may result in a screen pattern that does not
contain back reflection indications.
b. makes it difficult to locate discontinuities that lie
parallel to the entry surface.
c. usually indicates that a porous condition exists in
the metal.
d. decreases the penetrating power of the test.
A
a. may result in a screen pattern that does not
contain back reflection indications.
187
Q
- A discontinuity with a concave surface will:
a. diffuse the sound energy throughout the part.
b. cause the reflected beam to focus at a point
determined by the curvature of the discontinuity.
c. cause mode reinforcement of the ultrasonic wave.
d. propagate due to sound energy.
A
b. cause the reflected beam to focus at a point
determined by the curvature of the discontinuity.
188
Q
- Rayleigh waves:
a. are generated at the first critical angle.
b. are generated at the second critical angle.
c. are generated at either critical angle.
d. travel only in a liquid.
A
b. are generated at the second critical angle.
189
Q
- Angle beam testing of plate will often miss:
a. cracks that are perpendicular to the sound wave.
b. inclusions that are randomly oriented.
c. laminations that are parallel to the front surface.
d. a series of small discontinuities.
A
c. laminations that are parallel to the front surface.
190
Q
- Reducing the extent of the dead zone of a transducer by using a delay tip results in:
a. improved distance-amplitude correction in the
near field.
b. reduced frequency of the primary ultrasonic
beam.
c. reduced ability to detect discontinuities in the
near field.
d. improved accuracy in thickness measurement of
thin plate and sheet.
A
d. improved accuracy in thickness measurement of
thin plate and sheet.
191
Q
- In a plate, skip distance can be calculated from which of the following formulas where (t = plate thickness, Ɵ= angle of sound beam refraction, and V = sound velocity):
a. s = (2 x t)/tan Ɵ.
b. s = 2 x t x sin Ɵ.
c. s = 2 x t x tan Ɵ.
d. s = 2 xv x sin Ɵ.
A
c. s = 2 x t x tan Ɵ.
192
Q
- The technique of examining an ultrasonic reflector
from different directions might be used to enable the
technician to:
a. distinguish between different types of discontinuities.
b. predict the useful service life of the test specimen.
c. distinguish between discontinuity indications and
spurious or false indications.
d. accept an indication that appeared to be rejectable
from the fust test direction.
A
a. distinguish between different types of discontinuities.
193
Q
- Attenuation is the loss of the ultrasonic wave energy
during the course of propagation in the material due
to:
a. reflection and refraction.
b. dispersion and diffraction.
c. absorption and scattering.
d. composition and shape.
A
c. absorption and scattering.
194
Q
- In immersion shear wave testing, waves are normally generated by angulating the transducer beyond the first critical angle. What is the direction of the
material’s particle motion?
a. The same as the wave propagation.
b. Normal to the material surface.
c. Parallel to the direction of wave propagation.
d. Perpendicular to the direction of wave
propagation.
A
d. Perpendicular to the direction of wave
propagation.
195
Q
- Which of the following modes of vibration are
quickly dampened out when testing by the
immersion method?
a. Longitudinal waves.
b. Shear waves.
c. Transverse waves.
d. Surface waves.
A
d. Surface waves.
196
Q
- Which ultrasonic test frequency would probably
provide the best penetration in a 30 cm (12 in.) thick
specimen of coarse-grained steel?
a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz
A
a. 1 MHz
197
Q
197 A quartz crystal cut so that its major faces are parallel to the Z and Y axes and perpendicular to the X axis is called:
a. a Y-cut crystal.
b. an X-cut crystal.
c. a Z-cut crystal.
d. a ZY-cut crystal.
A
b. an X-cut crystal.
