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
A
103
Q
A
104
Q
A
