@ Generally, the best ultrasonic testing method for detecting
discontinuities oriented along the fusion zone in a welded plate
is:
\d
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. Sorry! The surface waves do not propagate through the
thickness of a thick plate.
^B. No, a straight zero degree test is not the best approach.
^C. Incorrect, surface waves do not propagate in immersion mode.
^D. You got it!
@ 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:
\b
A. A continuous wave display.
B. An A-scan presentation.
C. A B-scan presentation.
D. A C-scan presentation.
^A. Sorry, you are wrong.
^B. You are correct.
^C. No, a B-scan presents a cross-sectional view.
^D. Sorry! The C-scan presents a plan view.
@ At a water-to-steel interface the angle of incidence in water
is 7 degrees. The principal mode of vibration that exists in the
steel is:
\c
A. Longitudinal
B. Shear
C. Both A and B
D. Surface
^A. Yes, but there is another type of wave too. Apply Snell's
Law.
^B. Yes, but there is another type of wave too. Apply Snell's
Law.
^C. You got it!
^D. Incorrect, apply Snell's law.
@ In a liquid medium, the only mode of vibration that exists is:
\a
A. Longitudinal
B. Shear
C. Both A and B
D. Surface
^A. You are correct.
^B. No, this mode does not exist in liquids.
^C. No, only one of the above exists in liquids.
^D. Sorry! Surface waves do not travel through the liquids.
@ 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 rate.
\ d
^A. No. Look at the units.
^B. No. Look at the units.
^C. Sorry! Frequency is related to the transducer.
^D. You are correct.
@ In a basic pulse-echo ultrasonic instrument, the component that coordinates the action and timing of other components iscalled a:
|A. Display unit or CRT.|
B. Receiver.|
C. Marker circuit or range marker circuit.|
D. Synchronizer, clock, or timer.
\d
^A. Sorry! Information is displayed on CRT.
^B. Sorry! Receiver amplifies a signal.
^C. Sorry! Try again.
^D. Excellent!
@ In a basic pulse-echo ultrasonic instrument, the component that produces the voltage that activates the search unit is called:
A. An amplifier|
B. A receiver|
C. Pulser|
D. A synchronizer
\c
^A. Sorry! An amplifier amplifies a signal.
^B. Sorry! An amplifier amplifies a signal.
^C. You are absolutely correct.
^D. Sorry! Synchronizer coordinates the action and timing of
components.
@ In a basic-pulse-echo ultrasonic instrument, the voltage producing component which activates the search unit is called:
A. Sweep circuit|
B. Receiver|
C. Pulser|
D. Synchronizer
\a
^A. Excellent
^B. Sorry! Receiver amplifies the signal.
^C. Sorry! Pulser produces voltage that activates the search
unit.
^D. Sorry! Synchronizer coordinates the action and timing of
components.
@ In a basic pulse-echo ultrasonic instrument, the component that produces visible signals on the CRT which are used to measuredistance is called a:
A. Sweep circuit|
B. Marker circuit|
C. Receiver circuit|
D. Synchronizer
\b
^A. Sorry! Try again.
^B. You've got it.
^C. Sorry! Receiver amplifies the signal.
^D. Sorry! The synchronizer coordinates action and timing.
@ Most basic pulse-echo ultrasonic instruments use:
\b
A. Automatic read-out equipment.
B. An A-scan presentation.
C. A B-scan presentation.
D. A C-scan presentation.
^A. No, most equipment have signal amplitude and time display.
^B. You are correct.
^C. No, most equipment have signal amplitude and time dispplay.
^D. No, most equipment have signal amplitude and time display.
@ The cathode ray tube screen will display a plan view of the part outline and defects when using:
|A. Automatic read-out equipment.|
B. An A-scan presentation.|
C. A B-scan presentation.|
D. A C-scan presentation.
\d
^A. Incorrect. Try harder.
^B. Sorry! A-scan shows signal amplitude and time display.
^C. No, a B-scan shows a cross sectional view.
^D. You are right.
@ The incident angles at which 90 degrees refraction of longitudinal and shear waves occurs are called:
A. The normal angles of incidence.|
B. The critical angles.|
C. The angles of maximum reflection.|
D. None of the above
\b
|.
^A. No. The key word is "90 degrees refraction."
^B. You are correct.
^C. No. The key words are "90 degrees refraction."
^D. No. There is a correct answer.
@ 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. You are correct.
^B. Sorry! In this case, the particle displacement is
perpendicular.
^C. No, in this case, particle displacement is complex.
^D. No, in this case, particle displacement is elliptical.
@ Which of the following modes of vibration are quickly damped out when testing by the immersion method?
|A. Longitudinal waves|
B. Shear waves|
C. Transverse waves|
D. Surface waves
\d
^A. No. Longitudinal waves travel through water.
^B. No. Shear waves travel through metal even though it is
immersed.
^C. No. Transverse waves travel through metal even though it is
immersed.
^D. You are correct.
@ The motion of particles in a shear wave is:
|A. Parallel to the direction of propagation of the ultrasonicbeam.|
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 degrees to the direction of beampropagation.
\b
^A. No, this defines the longitudinal waves.
^B. You are correct.
^C. No, this defines the surface waves.
^D. Sorry! Please try again.
@ In contact testing, shear waves can be induced in the test material by:
A. Placing a X-cut crystal directly on the surface of thematerials 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 thetransducer|
D. Using a transducer mounted on a plastic wedge so that sound
\d
|enters the part at an angle.
^A. No, this will generate longitudinal waves.
^B. No. This is through transmission testing.
^C. No, this will simply focus sound beam.
^D. You are correct.
@ As frequency increases in ultrasonic testing, the angle of crystal:
A. Decreases.|
B. Remains unchanged.|
C. Increases.|
D. Varies uniformly through each wavelength.
beam divergence of a given diameter \a
|^A. You are correct.
^B. Sorry! Beam divergence is a function of wave length divided
by transducer diameter.
^C. Sorry! Beam divergence is a function of wave length divided
by transducer diameter.
^D. Sorry! Beam divergence is a function of wave length divided
by transducer diameter.
@ Which of the following is not an advantage of contact ultrasonic search units(probes) adapted with lucite shoes?
|A. Eliminates most of the crystal wear.|
B. Permits adaptation to curved surfaces.|
C. Decreases sensitivity.|
D. Allows ultrasound to enter a part's
\c
surface at oblique angles.
^A. No, this is an advantage.
^B. No, this is an advantage.
^C. You are correct.
^D. No, this is an advantage.
@ In which medium listed below would the velocity of sound be lowest?
|A. Air|
B. Water|
C. Aluminum|
D. Stainless steel
\a
^A. You are correct.
^B. Sorry! Velocity is a function of modulus and density. Liquids
generally have higher velocity than gases.
^C. Sorry! Velocity is a function of modulus and density.
Solids, generally have higher velocity than liquids and gases.
^D. Sorry! Velocity is a function of modulus and density.
Solids, generally have higher velocity than liquids and gases.
@ A longitudinal ultrasonic wave is transmitted from water into steel at an angle of 5 degrees from the normal. In such a case therefracted 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. You are right on target.
^B. No, apply Snell's law.
^C. No, think about Snell's law.
^D. No, you are incorrect.
@ The velocity of longitudinal waves will be highest in:
\c
A. Water
B. Air
C. Aluminum
D. Stainless steel
^A. Incorrect, generally have a higher velocity than the liquids.
^B. Incorrect, air has the lowest velocity.
^C. You got it.
^D. You are close but not quite right.
@ The acoustic impedance is:
A. Used to calculate the angle of reflection|
B. The product of the density of the material and thevelocity of sound in the material.|
C. Found by Snell's law|
D. Used to determine resonance values^
\ b|
A. Sorry! Acoustic impedance is used for calculatingtransmission and reflection of ultrasound.^
B. You are right on target.^
C. Sorry! Acoustic impedance is used for calculatingtransmission and reflection of ultrasound.^
D. Sorry! Acoustic impedance is used for calculatingtransmission and reflection of ultrasound.
@ In steel, the velocity of sound is greatest in which of the following modes of vibration?
A. Longitudinal|
B. Shear|
C. Surface waves.|
D. Sound velocity is identical in all modes, in a givenmaterial.
\ a
| ^ A. You are right on target.
^ B. No, shear waves travel half as fast as longitudinal waves.
^ C. No, surface waves are slower than shear waves.
^ D. Sorry! Velocities are significantly different for
different wave modes.
@ Thin sheet may be inspected with the ultrasonic wave directed normal to the surface by observing:
| A. The amplitude of the front surface reflection.|
B. The multiple reflection pattern.|
C. All front surface reflections|
D. None of the above.
\ b
^ A. No, front surface signal will have a considerable dead
zone.
^ B. Outstanding
^ C. Sorry! Try again.
^ D. No, there is a correct answer.
@ A diagram in which the entire circuit stage or sections are shown by geometric figures and the path of the signal or energy bylines and/or arrows is called a:
| A. Schematic diagram|
B. Blueprint|
C. Block diagram|
D. None of the above
\ c
^ A. No, schematic diagrams show electrical circuits.
^ B. Sorry! But you are real close. Try again.
^ C. You've got it.
^ D. No, there is a correct answer.
@ Of the piezoelectric materials listed below, the mostefficient sound transmitter is:
A. Lithium sulfate|
B. Quartz|
C. Barium titanate|
D. Silver oxide^
\ c|
A. No, this is the best receiver.^
B. Sorry! Try again.^
C. You got it.^
D. Incorrect, silver oxide is not a piezoelectric material.
^ A. Yes, but you are only partially correct.
^ B. Yes, but you are only partially correct.
^ C. Yes, but you are only partially correct.
^ D. You got it
@ Of thepiezoelectric materials listed below, the most efficient sound receiver is:
| A. Lithium sulfate|
B. Quartz|
C. Barium titanate|
D. Silver oxide.
\ a
^ A. You are correct.
^ B. Sorry! Please try again.
^ C. No, this is the best transmitter.
^ D. Incorrect, silver oxide is not a piezoelectric material.
@ The wavelength of an ultrasonic wave is: A. directly proportional to velocity and frequency.|
B. directly proportional to velocity and inverselyproportional to frequency.|
C. inversely proportional to velocity and directlyproportional to frequency.| D. equal to the product of the velocity and frequency.
\ b|
.^ A. Incorrect since velocity=frequency x wavelength.^
B. You got it.^
C. No, apply the formula velocity=frequency x wavelength again.^
D. No, apply the formula velocity=frequency x wavelength
@ Beam divergence is a function of the dimensions of the crystaland the wavelength of the beam transmitted through a medium, and it:A. increases if the frequency or crystal diameter isdecreased.|
B. decreases if the frequency or crystal diameter isdecreased.|
C. increases if the frequency is increased and crystaldiameter decreased.|
D. decreases if the frequency is increased and crystaldiameter is decreased
\ a|
.^ A. You got it.^
B. Sorry! Alpha is a function of velocity/(diameter*frequency).^
C. Sorry! Alpha is a function of velocity/(diameter*frequency).^
D. Sorry! Alpha is a function of velocity/(diameter*frequency).
@ The most commonly used method of producing shear waves in a test part when inspecting by the immersion method is:
A. By transmitting longitudinal waves into a part in adirection perpendicular to its front surface.|
B. By using two crystals vibrating at different frequencies.|
C. By using a Y-cut quartz crystal.|
D. By angulating the search tube to the proper angle.
\ d
|^ A. No, the transducer is positioned at an angle.
^ B. Sorry, you are wrong.
^ C. Sorry! This is one way, but not the most common way.
^ D. You are correct.
@ In general, which waves will travel around gradual curves withlittle or no reflection from the curve?
| A. Transverse waves.|
B. Surface waves.|
C. Shear waves.|
D. Longitudinal waves.
\ b
^ A. No, transverse waves are reflected from curved surface.
^ B. Excellent
^ C. No, shear waves are reflected from curved surface.
^ D. No, longitudinal waves are reflected from curved surfaces.
@ When using two separate search units (one a transmitter, theother a receiver), the most efficient combination would be:
A. A quartz transmitter and a barium titanate receiver.|
B. A barium titanate transmitter and a lithium sulfatereceiver.|
C. A lithium sulfate transmitter and a barium titanatereceiver.|
D. A barium titanate transmitter and a quartz receiver
\ b|
.^ A. No, quartz is not a very good transmitter or receiver.^
B. You are correct.^
C. Sorry! Lithium sulfate is a good receiver.^
D. No, quartz is not a very good transmitter or receiver.
@ To evaluate and accurately locate discontinuities afters canning a part with a paintbrush transducer, it is generallynecessary to use a:
A. Search unit with a smaller crystal.| B. Scrubber.|
C. Grid map.|
D. Crystal collimator
\ a
|.
^ A. You are correct.
^ B. Sorry! This choice is irrelevant.
^ C. Sorry! This choice is irrelevant.
^ D. Sorry! This choice is irrelevant.
@ As the impedance ratio of two dissimilar materials increases,
the percentage of sound coupled through an interface of such materials:
\ a
A. Decreases.
B. Increases.
C. Is not changed.
D. May increase or decrease.
^ A. Super
^ B. No. Apply the formula for reflection and transmission
factors.
^ C. No, higher the impedance mismatch, the more difficult the
transmission.
^ D. No, higher the impedance mismatch, the more difficult the
transmission.
@ Low frequency sound waves are not generally used to test thin
materials because of:
\ c
A. The rapid attenuation of low frequency sound.
B. Incompatible wavelengths.
C. Poor near-surface resolution.
D. None of the above will actually limit such a test.
^ A. Incorrect. What happens to the resolution
^ B. Incorrect. What happens to the resolution
^ C. You are correct.
^ D. Incorrect. What happens to the resolution
| B. A collimator.
| C. An angle plane angulator.
| D. A jet-stream unit.
^ A. Sorry! This answer is incorrect.
^ B. You are correct.
^ C. Sorry! This answer is incorrect.
^ D. Sorry! This answer is incorrect.
@ The maximum scanning speed possible is primarily determined
by:
\ c
| A. The frequency of the searchunit.
| B. Viscous drag problems.
| C. The pulse repetition rate of the test instrument.
| D. The persistency of the CRT screen.
^ A. No, there is not relation between frequency and scanning
speed.
^ B. Sorry! This answer is incorrect.
^ C. You are correct.
^ D. Sorry! This answer is incorrect.
@ Surface waves are reduced to an energy level of approximately
1/25 of the original power at a depth of:
\ c
^ A. Sorry! Surface waves penetrate as much as one wavelength
below the surface.
^ B. No, surface waves do not penetrate much below one
wavelength.
^ C. Outstanding
^ D. No, surface waves do not penetrate much below one
wavelength.
@ The ultrasonic test method in which finger damping is most
effective in locating a discontinuity is:
\ c
| A. Shear wave
| B. Longitudinal wave
| C. Surface wave
| D. Compressional wave
^ A. No, all wave modes can be damped with finger. The key
words are "most effective."
^ B. No, all wave modes can be damped with finger. The key
words are "most effective."
^ C. Absolutely correct.
^ D. No, all wave modes can be damped with finger. The key
words are "most effective."
@ Lamb waves can be used to detect:
\ a
| A. Laminar-type defects 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. You've got it.
^ B. No, lamb waves cannot be generated in thick materials.
^ C. No, lamb waves cannot be generated in thick materials.
^ D. No, lamb waves cannot be generated in thick materials.
\ c
A. Defect detection.
B. Sound wave characterization.
C. Thickness measurement of flaw detection in thin materials.
D. Attenuation measurements.
^ A. Incorrect. Delay-tip normally used to avoid dead zone.
^ B. Incorrect. Delay-tip normally used to avoid dead zone.
^ C. Excellent
^ D. Incorrect. Delay-tip normally used to avoid dead zone.
@ Acoustical lenses are commonly used for contour correction.
When scanning the inside of a pipe section by the immersion method,
which of the following lens types would be used?
\ b
A. Focused cup
B. Convex
C. Concave
D. Variable pitch
^ A. No, pipe curvature provides focussing in one plane.
^ B. Super! You are correct.
^ C. Sorry! Please try again.
^ D. Sorry! Please try again.
@ When the incident angle is chosen to be between the first and
second critical angles, the ultrasonic wave generated within the
part will be:
\ b
A. Longitudinal
B. Shear
C. Surface
D. Lamb
^ A. No, longitudinal wave does not exist beyond first critical
angle.
^ B. You are correct.
^ C. No, surface wave is generated after second critical angle.
^ D. No, lamb wave is generated after second critical angle.
@ The attenuation of energy within a material in the far field of the ultrasonic beam may be expressed as the:
| A. Arithmetic mean
B. Geometrical average
C. Exponential average
D. Exponential decay
^ A. Wrong. It decreases rapidly.
^ B. Wrong. It decreases rapidly.
^ C. Wrong. It decreases rapidly.
^ D. You are correct.
| D. None of the above
^ A. You've got it.
^ B. No. Duration and amplitude are the two dimensions of an
ultrasonic signal.
^ C. Sorry! Please try again.
^ D. Sorry! Your choice is incorrect.
@ For aluminum and steel the longitudinal velocity is approximately_________ the shear velocity:
C.
A. Incorrect, shear wave velocity is much smaller thanlongitudinal wave velocity.^
B. You are absolutely correct.^
C. Incorrect, shear wave travel slower than longitudinalwaves.^
D. Incorrect. You are close.
@ The coated inside surface of the large end of a cathode raytube which becomes luminous when struck by an electron beam is called:
A. An electron gun|
B. An electron amplifier|
C. A CRT screen|
D. An electron counter^
\ c|
A. No, the key word is "screen."^
B. No, the key word is "screen."^
C. You are correct.^
D. No, the key word is "screen."
@ The phenomenon by which a wave strikes a boundary and changesthe direction of its propagation within the same medium is referredto as:
A. Divergence|
B. Impedance|
C. Angulation|
D. Reflection^
\ d|
A. No, divergence is a function of wavelength/transducerdiameter^
B. No, impedance=velocity*density^
C. Sorry! Please try again.^
D. You've got it.
@ The change in direction of an ultrasonic beam when it passesfrom one medium to another whose velocity differs from that ofthe first medium is called:
A. Refraction|
B. Rarefaction|
C. Angulation|
D. Reflection^
\ a|
A. You've got it.^
B. No, rarefaction is associated with the way longitudinalwave propagates.^
C. Sorry! This answer is incorrect.^
D. No, reflection occurs within the same medium.
@ Water travel distance for immersion inspections should be:\ a|
A. Such that the second front reflection does not appearbetween the first front and back reflections.| B. Exactly 3 inches.| C. Less than 3 inches.| D. Always equal to the thickness of the material beinginspected.^ A. You are correct.^ B. No. It depends on material thickness and velocity.^ C. No. It depends on material thickness and velocity.^ D. No, this can cause a confusing screen or presentation.
