UT - Questions and Answers

1.

ULTRASONICS TESTING LEVEL I

2. @ The reference holes in standard aluminum area-amplitude ultrasonic test blocks contain: \a | A. Flat-bottomed holes | B. Concave-surface holes | C. Convex-surface holes | D. Conical-shaped holes ^ A. You are absolutely right. ^ B. No, holes are designed to have a plane surface. ^ C. No, holes are designed to have a plane surface. ^ D. No, holes are designed to have a plane surface. 3.

@ The gradual loss of sonic energy as the ultrasonic vibrations

travel through the material is referred to as: \d | A. Reflection | B. Refraction | C. Reproducibility | D. Attenuation ^ A. No, the key words are "gradual loss". ^ B. No, the key words are "gradual loss". ^ C. No, reproducibility in this case is not a valid answer. ^ D. Excellent

4.

@ A term used to describe numerous small indications on the

cathode ray tube screen resulting from test part structure, numerous small discontinuities, or both is often referred to as: \c | A. Multiple back reflections | B. Multiple front reflections | C. Hash | D. Resonance ^ A. No, normally back reflections are large. ^ B. No, normally front reflections are large. ^ C. You've got it. ^ D. No, there is no real connection between the question and this choice. 5.

@ When testing a plate, increasing the frequency of an

ultrasonic longitudinal wave will result in: \c | A. An increase in its velocity | B. A decrease in its velocity | C. No change in its velocity | D. A reversal in its velocity ^ A. No, velocity depends on material properties. ^ B. No, velocity depends on material properties. ^ C. You're right. ^ D. No, this choice is irrelevant.

6.

@ Ultrasonic waves transmitted into and received from the test

material in the form of repetitive bursts of acoustic energy is called: \a | A. Pulse-echo testing | B. Continuous wave testing | C. Resonance testing | D. None of the above ^ A. Super! You are absolutely right. ^ B. No, the key phrase is "repetitive bursts" of energy. ^ C. No, the key phrase is "repetitive bursts" of energy. ^ D. No, there is a correct answer. 7.

@ Metal blocks which contain one or more drilled holes to

simulate discontinuities are called: \d | A. Scrubbers | B. Crystal collimators | C. Single plane angulators | D. Reference blocks ^ A. Sorry! Please try again. ^ B. Sorry! Please try again. ^ C. Sorry! Please try again. ^ D. Absolutely right. 8.

@ If the major dimensions of a discontinuity in a 6-inch thick

aluminum plate lie parallel to the entry surface at a depth of 3 inches, it will be best detected by: \a | A. A straight beam test | B. An angle beam test | C. A surface wave test | D. A lamb wave test ^ A. Outstanding ^ B. No, although this could be done, there is an easier method. ^ C. No, these waves will not penetrate 3 inches deep. ^ D. Sorry! You cannot excite lamb waves in such a thick material. 9.

@ The existence of a discontinuity will not produce its specific

indication on the CRT screen when using the: \d | A. Straight beam testing method | B. Surface wave testing method | C. Angle beam testing method | D. Immersion testing method ^ A. No, this will produce an indication. ^ B. Sorry! You've answered incorrectly. ^ C. Sorry! This choice is incorrect. ^ D. You've got it. 10.

@ The depth of a discontinuity cannot be determined when using:

\b | A. Straight beam testing method. | B. Through transmission testing method. | C. Angle beam testing method. | D. Immersion testing method. ^ A. No, presence of indication gives depth information. ^ B. You are correct. ^ C. No, presence of indication gives depth information. ^ D. No, presence of indication gives depth information. 11.

@ When inspecting coarse-grained material, which of the

following frequencies will generate a sound wave that will be most easily scattered by the grain structure? \d | A. 1.0 MHz | B. 2.25 MHz | C. 5 MHz | D. 10 MHz ^ A. No, scattering is dependent on frequency. Lower frequency causes relatively low scattering. ^ B. No, scattering is dependent on frequency. Lower frequency causes relatively low scattering. ^ C. No, scattering is dependent on frequency. Lower frequency causes relatively low scattering. ^ D. Super! you are absolutely right.

12.

@ Which of the following search units would contain the thickest

crystal? \a | A. A 1 megahertz search unit. | B. A 5 megahertz search unit. | C. A 15 megahertz search unit. | D. A 25 megahertz search unit. ^ A. You are absolutely correct. ^ B. No, the higher the frequency, the thinner the crystal. ^ C. No, the higher the frequency, the thinner the crystal. ^ D. No, the higher the frequency, the thinner the crystal. 13.

@ When performing a surface wave test, indications may result

from: \d | A. Surface discontinuities | B. Oil on the surface | C. Dirt on the surface | D. All three of the above ^ A. True, but the surface waves are also sensitive to any contamination or cracking on the surface. ^ B. True, but the surface waves are also sensitive to any contamination or cracking the surface. ^ C. True, but the surface waves are also sensitive to any contamination or cracking the surface.

^ D. You are correct. 14.

@ Search units constructed with a plastic wedge or standoff

between the transducer element and the test piece are commonly used for: \d | A. Dual transducer straight beam contact testing. | B. Angle beam contact testing. | C. Surface wave contact testing. | D. All of the above. ^ A. Although you are partially correct, there are also some other valid answers. ^ B. Although you are partially correct, there are also some other valid answers. ^ C. Although you are partially correct, there are also some other valid answers. ^ D. You are correct. 15.

@ A search unit containing three or more individual transducer

elements is often referred to as a: \c | A. Dual transducer | B. Sandwich transducer | C. Mosaic transducer | D. None of the above ^ A. No, a dual transducer has two transducers.

^ B. No, this choice is incorrect. ^ C. You are correct. ^ D. No, there is a valid answer. 16.

@ Sound can be focused by means of special curved adapters

located in front of the transducer element. These adapters are referred to as: \b | A. Scrubbers | B. Acoustic lenses | C. Angle beam adapters | D. Single plane adapters ^ A. Incorrect. Looking for focussing adapters or lenses. ^ B. You are correct. ^ C. Incorrect. Looking for focussing adapters or lenses. ^ D. Incorrect. Looking for focussing adapters or lenses. 17.

@ A test method in which the parts to be inspected are placed in

a water bath or some other liquid couplant is called: \b | A. Contact testing | B. Immersion testing | C. Surface wave testing | D. Through transmission testing ^ A. Sorry! Contact testing does not require a water bath. ^ B. Outstanding

^ C. No, it is difficult, if not impossible, to do surface wave testing when material is submerged. ^ D. No, this could be done in contact or immersion mode. 18.

@ A separate time base line imposed on the viewing screen of

some ultrasonic testing instruments that permits measurement of distances is often referred to as: \c | A. An initial pulse | B. A time/distance line | C. A marker | D. Through transmission testing ^ A. No, initial pulse is incorrect. ^ B. Incorrect. Please try again. ^ C. You are absolutely correct. ^ D. Incorrect. Please try again. 19.

@ A term used to describe the ability of an ultrasonic testing

system to distinguish between the entry surface response and the response of discontinuities near the entry surface is: \d | A. Sensitivity | B. Penetration | C. Segregation | D. Resolution ^ A. No, "how small a defect can be found" defines sensitivity.

^ B. No, "how deep in a material on sound waves propagate" defines penetration. ^ C. Incorrect. Segregation means to "isolate or to set apart. ^ D. Excellent 20.

@ The phenomenon whereby an ultrasonic wave changes direction

when the wave crosses a boundary between materials with different velocities is called: \a | A. Refraction | B. Reflection | C. Penetration | D. Rarefaction ^ A. You are correct. ^ B. No, reflection occurs within the same medium. ^ C. No, "how deep in a material or sound waves propagate" defines penetration. ^ D. No, rarefaction and compression describe the way in which longitudinal wave propagates. 21.

@ In a test where the transducer is not perpendicular to the

inspection surface, the angle of incidence is equal to: \b | A. The angle of refraction. | B. The angle of reflection. | C. The shear wave angle.

| D. One-half the shear wave angle. ^ A. No, angle of refraction is determined from the Snell's law. ^ B. You are absolutely correct. ^ C. No, there is no relationship with shear wave angle. ^ D. No, there is no relationship with shear wave angle. 22.

@ The product of the acoustic velocity of sound in a material

and the density of the material is the factor that determines the amount of reflection or transmission of ultrasonic energy when it reaches an interface. This term is called: \a | A. Acoustic impedance | B. Velocity | C. Wave length | D. Penetration ^ A. Excellent ^ B. No, z=velocity * density ^ C. No, z=velocity * density ^ D. No, "how deep in a material on sound waves propagate" defines penetration. 23.

@ Ultrasonic waves that travel along the surface of a material and

whose particle motion is elliptical are called: \d | A. Shear waves | B. Transverse waves

| C. Longitudinal waves | D. Rayleigh waves ^ A. No, particle motion is transverse to the propagation direction. ^ B. No, particle motion is transverse to the propagation direction. ^ C. No, particle motion is parallel to the propagation direction. ^ D. Super! You are correct. 24.

@ The interference field near the face of a transducer is often

referred to as the: \a | A. Fresnel zone. | B. Acoustic impedance. | C. Exponential field. | D. Phasing zone. ^ A. You are correct. ^ B. No, acoustic impedance is a product of density and velocity. ^ C. Sorry! There is no such term in Ultrasonic Testing. ^ D. Sorry! There is no such term in Ultrasonic Testing. 25.

@ When the incident angle is chosen to be between the first and

second critical angles, the ultrasonic wave mode within the part will be a: \b

| A. Longitudinal wave | B. Shear wave | C. Surface wave | D. Lamb wave ^ A. No, longitudinal waves are not present. ^ B. You are correct. ^ C. No, surface waves are not present. ^ D. No, lamb waves are not present. 26.

@ The formula used to calculate the angle of refraction within a

material is called: \c | A. Fresnel's law | B. Fraunhofer's law | C. Snell's law | D. Lamb's law ^ A. Sorry! There is no such term in UT. ^ B. Sorry! There is no such term in UT. ^ C. You are correct. ^ D. Sorry! There is no such term in UT. 27.

@ In a material with a given velocity, when frequency is increased,

the wavelength will: \c | A. Not be effected | B. Increase

| C. Decrease | D. Double ^ A. No, velocity is a product of frequency and wavelength. ^ B. No, velocity is a product of frequency and wavelength. ^ C. You are correct ^ D. No, velocity is a product of frequency and wavelength. 28.

@ Which circuits electronically amplify return signals from the

receiving transducer and often modify the signals into a form suitable for display? \d | A. Pulser circuits | B. Marker circuits | C. Timer circuits | D. Receiver-amplifier circuits ^ A. No, pulser circuit excites the transducer to send ultrasonic signals. ^ B. No, please try harder. ^ C. No, please try harder. ^ D. You are correct. 29.

@ What is the most common type of data display used for ultrasonic

examination of welds? \a | A. An A-scan display | B. A B-scan display

| C. A C-scan display | D. An x-y plot ^ A. Outstanding ^ B. No, modern computer based systems can display B-scan. ^ C. No, however modern computer based systems can display C-scan. ^ D. No, UT uses A, B, or C-scan. 30.

@ Which is a plot of signal amplitude versus time?

\a | A. An A-scan display | B. A B-scan display | C. A C-scan display | D. None of the above ^ A. You are absolutely correct. ^ B. No, B-scan displays position vs. distance (side view). ^ C. No, C-scan displays a plan view. ^ D. No, there is a correct answer. @ Which circuits modify the return signal from the receiving transducer into a form suitable for display on an oscilloscope or other output device? \b | A. Pulser | B. Receiver-amplifier | C. Clock

| D. Sweep ^ A. No, pulser circuit excites the transducer to send ultrasonic signals. ^ B. You are correct. ^ C. Sorry! Please try again. ^ D. Sorry! Please try again. 31.

@ Which circuit generates a burst of energy which is applied to

the sending transducer? \a | A. Pulser | B. Receiver-amplifier | C. Damping | D. Clock ^ A. You are correct. ^ B. No, Receiver-amplifier modifies return signal for display. ^ C. Sorry! Please try again. ^ D. No, clock coordinates operation of the entire UT system. 32.

@ Which circuit coordinates operation of the entire ultrasonic

instrument system? \c | A. Damping | B. Receiver-amplifier | C. Clock | D. Power supply

^ A. Sorry! Please try again. ^ B. No, Receiver-amplifier modifies return signal for display. ^ C. You are correct. ^ D. Incorrect. Please try again. 33.

@ A plan view display or recording of a part under examination

is called: \a | A. A C-scan display. | B. An A-scan display. | C. An X-axis plot. | D. A strip chart recording. ^ A. You are absolutely correct. ^ B. No, A-scan displays time vs. amplitude. ^ C. No such plot exists in Ultrasonic Testing. ^ D. Sorry! Please try again. 34.

@ Ultrasonic data which is presented in a form representative of

the cross-section of the test specimen is called: \b | A. An A-scan presentation. | B. A B-scan presentation. | C. A C-scan presentation. | D. An X-Y plot. ^ A. No, A-scan displays time vs. amplitude. ^ B. You are absolutely correct.

^ C. No, C-scan displays plan view. ^ D. No, such plot exists in Ultrasonic Testing. 35.

@ What type of ultrasonic examination uses wheel-type search units

that eliminate the use of a tank? \d | A. Through transmission testing. | B. Contact testing. | C. Resonance testing. | D. Immersion testing. ^ A. Sorry! Your answer is incorrect. The key words are "eliminate use of a tank. ^ B. Sorry! Youranswer is incorrect. The key words are "eliminate use of a tank. ^ C. Sorry! Your answer is incorrect. The key words are "eliminate use of a tank. ^ D. Outstanding! 36.

@ In addition to other functions, a probe manipulator in a

mechanical immersion scanning unit permits: \c | A. Use of the through transmission technique. | B. Use of high scanning speeds. | C. Detection of obliquely-oriented discontinuities. | D. Utilization of less skilled operators. ^ A. No, a through transmission requires two manipulators.

^ B. No, this is not always the case. ^ C. You are correct. ^ D. No, a probe manipulator has little to do with an operator's skills. @ A type of data presentation most likely to be used with a high speed automatic scanning system is: \c | A. An A-scan presentation. | B. A velocity versus amplitude plot. | C. A C-scan presentation. | D. A plot of echo height versus depth. ^ A. No, it is difficult to interpret A-scan's at high speed. ^ B. There is no such plot in Ultrasonic Testing. ^ C. Excellent ^ D. No, this is incorrect. 37.

@ The component in a conventional immersion system which spans

the width of the immersion tank is called: \b | A. An articulator. | B. A bridge. | C. A manipulator. | D. A search tube. ^ A. No, an articulator lets you angulate the search unit. ^ B. You are correct.

^ C. No, a manipulator provides angulation facility. ^ D. No, a search tube allows for changing water path. 38.

@ Which component in an ultrasonic immersion system is used to

adjust and maintain a known transducer angle? \b | A. A carriage | B. A manipulator | C. A search tube | D. An index system ^ A. No, a carriage allows movement in the x and y directions. ^ B. You are correct. ^ C. No, a search tube is used for changing water path. ^ D. No, this answer is not correct. 39.

@ An amplitude type gate is necessary for all:

\c | A. Shear wave examinations. | B. Longitudinal wave examinations. | C. Automatic examinations. | D. Manual examinations. ^ A. No, most shear exams are manual. ^ B. No, gates are useful for high speed data acquisition and recording. ^ C. You are correct. ^ D. No, gates are useful for high speed data acquisition and

recording. 40.

@ When a C-scan recording is used to produce a permanent record

of an ultrasonic test, the information displayed is typically the: \d | A. Discontinuity depth and size. | B. Discontinuity depth, orientation, and size. | C. Discontinuity location and depth. | D. Discontinuity location and size (plan view). ^ A. No, a C-scan does not provide depth information. ^ B. No, a C-scan does not provide depth information. ^ C. No, a C-scan does not provide depth information. ^ D. You are absolutely correct. 41.

@ Rough entry surface conditions can result in:

\c | A. A loss of echo amplitude from discontinuities. | B. An increase in the width of the front surface echo. | C. Both A and B. | D. None of the above. ^ A. Although you are close, consider what happens to the front surface echo. ^ B. Although you are close, consider what happens to the signal amplitude. ^ C. Super! You are absolutely correct. ^ D. No, there is a valid answer choice.

42.

@ As the grain size increases in a material, its principal effect

in ultrasonic testing is on: \b | A. The velocity of sound. | B. The attenuation. | C. The acoustic impedance. | D. The angle of refraction. ^ A. No, velocity depends on modulus of elasticity and density. ^ B. You are correct. ^ C. No, in theory, grain size has no affect on acoustic impedance. ^ D. No, in theory, grain size has no affect on the angle of refraction. 43.

@ In straight beam pulse echo testing a discontinuity with a

rough reflecting surface perpendicular to the incident wave will have what effect on the detected signal in comparison to a smooth flat-bottom hole of the same size? \b | A. Increase it. | B. Decrease it. | C. Have no effect on it. | D. Decrease the width of the pulse of it. ^ A. No, surface roughness will scatter sound energy. ^ B. You are correct.

^ C. No, surface roughness will scatter sound energy. ^ D. No, surface roughness will scatter sound energy. 44.

@ Ultrasonic vibrations can be propagated only in the longitudinal

mode in which of the following media? \a | A. Machine oil | B. Aluminum | C. Ice | D. Beryllium ^ A. You are absolutely correct. ^ B. No, In metals, L-waves as well as other types of waves will be generated. ^ C. No, solids support longitudinal as well as other types of waves. ^ D. No, solids support longitudinal as well as other types of waves. 45.

@ If the velocity of a longitudinal mode wave in a given

homogeneous material is .625 cm/micro sec. at 1/2 inch below the surface, what is the velocity at 2 inches below the surface? \c | A. 1/4 the velocity at 1/2 inch. | B. 1/2 the velocity at 1/2 inch. | C. The same as the velocity at 1/2 inch. | D. None of the above.

^ A. Incorrect, velocity is a function of modulus and density. ^ B. Incorrect, velocity is a function of modulus and density. ^ C. You are correct. ^ D. No, there is a valid answer choice. 46.

@ If a 5.0 MHz transducer is substituted for a 2.25 MHz transducer,

what would be the effect on the wavelength of a longitudinal mode wave produced in the test specimen? \b | A. The wavelength would be longer. | B. The wavelength would remain constant. | C. The wavelength would be shorter. | D. The wavelength would vary directly with the acoustic impedance. ^ A. No, not according to c=frequency x wavelength. ^ B. No, not according to c=frequency x wavelength. ^ C. Very good! ^ D. No, think about the formula c=frequency x wavelength. 47.

@ What can cause irrelevant indications on the cathode ray tube?

\d | A. Contoured surfaces | B. Edge effects | C. Surface conditions | D. All of the above ^ A. Although you are partially correct, there are also other

irregularities that produce an identical affect. ^ B. Although you are partially correct, there are also other irregularities that produce an identical affect. ^ C. Although you are partially correct, there are also other irregularities that produce an identical affect. ^ D. You are absolutely correct. 48.

@ The proper interpretation and evaluation of the presented defect

signals are essential to any nondestructive test. A common method for the estimation of defect size is the use of a: \d | A. Double transducer test | B. Piezoelectric standard | C. Mode conversion | D. Reference standard ^ A. No, calibration and/or standards are required. ^ B. Sorry! This is an incorrect answer. longitudinal, shear waves etc. ^ C. No, mode conversion describes incident wave converting into longitudinal shear waves etc. ^ D. Outstanding! 49.

@ Another name for Fresnel Zone is:

\b | A. Fraunhofer Zone | B. Near Field

| C. Far Field | D. Torrid Zone ^ A. No, a fraunhofer zone is the exact opposite. ^ B. You are correct. ^ C. No, a far field is the opposite of a fresnel zone. ^ D. No, there is no such zone in Ultrasonic testing. 50.

@ Attenuation is a:

\b | A. Test display characteristic. | B. Test material parameter. | C. Transducer characteristic. | D. Form of testing. ^ A. No, attenuation depends on grain size, anisotropy, etc. ^ B. You are correct. ^ C. No, attenuation depends on grain size, anisotropy, etc. ^ D. No, attenuation depends on grain size, anisotropy, etc. 51.

@ For discontinuity geometries other than flat, the echo

amplitude is usually ____________ from that observed for a flat defect, of similar orientation perpendicular to the sound beams. \c | A. Identical | B. Increased | C. Decreased | D. Elongated

^ A. No, reflector shape change will change the signal amplitude. ^ B. No, there is more dispersion from other than the flat reflector. ^ C. You are correct. ^ D. No, amplitude should increase or decrease. Elongated amplitude has no meaning. 52.

@ What must be done to evaluate discontinuities that are oriented

at an angle to the entry surface so that the sound beam will strike the plane of the discontinuity at right angles? \c | A. Change the frequency | B. Grind the surface | C. Angulate the search unit | D. Increase the gain ^ A. No, consider the case where the sound beam is perpendicular to the discontinuity. ^ B. No, surface grinding can only help if there is surface roughness. ^ C. You are correct. ^ D. No, this won't help in this case. Consider the case where the sound beam is perpendicular to the discontinuity. 53.

@ The pulser circuit in an ultrasonic instrument is used to:

\b | A. Control the horizontal and vertical sweep.

| B. Activate the transducer. | C. Control transducer timing between transmit and sweep. | D. Generate markers that appear on horizontal sweep. ^ A. No, how do you energize the search unit? ^ B. You are correct. ^ C. No, how do you energize the search unit? ^ D. No, how do you energize the search unit? 54.

@ An A-scan CRT display which shows a signal both above and below

the sweep line is called a: \b | A. Video display | B. RF display | C. Audio display | D. Frequency modulated display ^ A. No, video display shows signals above the sweep line. ^ B. Excellent! ^ C. No, Audio-means "which can be heard. ^ D. Sorry!! You've answered incorrectly. 55.

@ A B-scan display shows the relative:

\b | A. Distance a discontinuity is from the transducer and its through- dimension thickness. | B. Distance a discontinuity is from the transducer and its length in the direction of transducer travel.

| C. Cross-sectional area of a discontinuity above a predetermined amplitude. | D. None of the above. ^ A. No, but you are close. ^ B. You are correct. ^ C. Sorry! You have answered incorrectly. ^ D. No, there is a correct answer. 56.

@ Surface (Rayleigh) waves traveling on the top face of a block:

\b | A. Are not reflected from a sharp edge corner. | B. Are reflected from a sharp edge corner. | C. Travel through the sharp edge corner and are reflected from the lower edge. | D. Are absorbed by a sharp corner. ^ A. Sorry! Any surface discontinuity will reflect Rayleigh waves. ^ B. You are right. ^ C. No, any surface discontinuity will reflect signals. ^ D. No, any surface discontinuity will reflect signals. 57.

@ Surface (Rayleigh) waves traveling on the top face of a block

are attenuated by the presence of: \d | A. A curved surface | B. A heavy couplant

| C. Machining marks and rough surfaces. | D. Both B and C ^ A. No, Rayleigh waves are not attenuated by a curved surface. ^ B. Yes, but there are factors too. ^ C. You are close! Try again. ^ D. You are absolutely correct. 58.

@ The velocity of sound in a material is dependent upon the:

\c | A. Frequency of the wave | B. Wavelength | C. Material properties | D. Vibration cycle ^ A. No, in most materials velocity is independent of frequency. ^ B. Wavelength=Velocity/frequency. ^ C. You are absolutely correct. ^ D. Sorry! Please try again. 59.

@ To vary or change the wavelength of sound being used to test a

part, you would change the: \a | A. Sound wave frequency. | B. Diameter of the transducer. | C. Electrical pulse voltage. | D. Pulse repetition rate. ^ A. You are absolutely correct.

^ B. No, changing diameters of transducers will only change beam spread. ^ C. No, electrical pulse voltage will only change penetration. ^ D. No, pulse repetition rate means how often you pulse the transducer, it has nothing to do with wavelength. 60.

@ Ultrasonic vibrations are commonly used to:

\d | A. Examine materials for discontinuities. | B. Examine materials for thickness. | C. Examine materials for mechanical properties. | D. All of the above. ^ A. True, but Ultrasonics can do much more. ^ B. True, but Ultrasonics can do much more. ^ C. True, but Ultrasonics can do much more. ^ D. Super! 61.

@ Which of the following has the longest Fresnel zone?

\d | A. 1/2-inch diameter 1.0 MHz. | B. 1/2-inch diameter 2.25 MHz. | C. 1-1/8-inch diameter 1.0 MHz. | D. 1-1/2-inch diameter 2.0 MHz. ^ A. No, N=(diameter square/(4*wave length)) ^ B. No, N=(diameter square/(4*wave length)) ^ C. No, N=(diameter square/(4*wave length))

^ D. You are correct. 62.

@ When contact testing, if the ultrasonic instrument is set with

an excessively high pulse repetition rate, which of the following may occur? \D | A. The screen trace will become too light to see. | B. The time-base line will become distorted. | C. The initial pulse will disappear. | D. Ghost or "phantom" indications will appear on screen during scanning. ^ A. No, trace is light if pulse repetition rate is too slow. ^ B. No, high gain distorts time base line. ^ C. No. Try harder. ^ D. Exactly! 63.

@ The advantages of immersion testing include which of the

following? \d | A. Inspection speed increased. | B. Ability to control and direct sound beams. | C. Adaptability for automated scanning. | D. All of the above. ^ A. True, but there are other advantages too. ^ B. True, but there are other advantages too. ^ C. True, but there are other advantages too.

^ D. You are absolutely correct. 64.

@ Longitudinal wave velocity in water is approximately

one-fourth the velocity in aluminum or steel. Therefore the minimum water path should be: \c | A. Four times the test piece thickness. | B. One-half the test piece thickness. | C. One-fourth the test piece thickness plus 1/4 inch. | D. None of the above. ^ A. Sorry, your answer is incorrect. ^ B. Sorry, you answer is incorrect. ^ C. Super! ^ D. No, there is a correct answer. 65.

@ In immersion testing a wetting agent is added to the water to:

\b | A. Adjust the viscosity. | B. Help eliminate the formation of air bubbles. | C. Prevent cloudiness. | D. None of the above. ^ A. No, the wetting agent is added to improve the impedance match. ^ B. Super! ^ C. No, the wetting agent is added to improve the impedance match.

^ D. No, there is a correct answer. 66.

@ The indication on the cathode ray tube(CRT) which represents

the far boundary of the material being tested is called: \d | A. Hash | B. The initial pause | C. The "main bang" | D. The back surface reflection ^ A. Hash is due to electronic noise and scattering from grains. ^ B. In ultrasonic terminology there is no such thing. The closest will be initial pulse. ^ C. "Main Bang" is the initial pulse or voltage pulse which excites the transducer. ^ D. You are absolutely correct! 67.

@ In immersion testing, the position of the search unit is often

varied to transmit sound into the test part at various angles to the front surface. Such a procedure is referred to as: \a | A. Angulation. | B. Dispersion. | C. Reflection testing. | D. Refraction. ^ A. You are correct! ^ B. Dispersion, simply put, could be called beam broadening.

The other three choices, in this case, are more relevant. ^ C. No, Reflection occurs when a sound beam is reflected. ^ D. Although you are close, this is not the correct answer. 68.

@ The cable that connects the ultrasonic instrument to the search

unit is specially designed so that one conductor is centered inside another. The technical name for such a cable is: \c | A. BX cable | B. Conduit | C. Coaxial cable | D. Ultrasonic conductor cable-grade 20 ^ A. Are you guessing? This answer is not applicable at all. Reread the choices and try again. ^ B. Sorry, Conduits are hollow from the inside. ^ C. Yes, the coaxial cable is the right answer. ^ D. There exists no such cable. Are you guessing? 69.

@ The process of comparing an instrument or device with a

standard is called: \b | A. Angulation | B. Calibration | C. Attenuation | D. Correlation ^ A. No, Angulation is a testing procedure in which sound is

transmitted at various angles. ^ B. Yes, the process is called calibration. ^ C. No, attenuation shows up as a decrease in signal amplitude. ^ D. Good guess, but wrong answer. 70.

@ Another name for a compressional wave is:

\c | A. Lamb wave | B. Shear wave | C. Longitudinal wave | D. Transverse wave ^ A. No, particle motion with respect to wave direction defines the type of wave. ^ B. No, in compression wave particle motion and direction of wave propagation are parallel. ^ C. You are absolutely correct. ^ D. No, in compression wave particle motion and direction of wave propagation are parallel. 71.

@ A second name for Rayleigh waves is:

\d | A. Shear waves | B. Longitudinal waves | C. Transverse waves | D. Surface waves ^ A. No, in Rayleigh waves particle motion is elliptical.

^ B. No, in Rayleigh waves particle motion is elliptical. ^ C. No, in Rayleigh waves particle motion is elliptical. ^ D. You're absolutely correct. 72.

@ A material used between the face of a search unit and the test

surface to permit or improve the transmission of ultrasonic vibrations from the search unit to the material being tested is called: \b | A. A wetting agent | B. A couplant | C. An acoustic transmitter | D. A lubricant ^ A. No, wetting agent is used to reduce surface tension so that fluid spreads over the surface. ^ B. You are correct. ^ C. Sorry! Please try again. ^ D. No, lubricant is used for reducing friction. 73.

@ The piezoelectric material in a search unit which vibrates to

produce ultrasonic waves is called: \c | A. A backing material | B. A lucite wedge | C. A transducer element or crystal | D. A couplant

^ A. No, backing material is behind the piezoelectric material. ^ B. No, wedge is in front of piezoelectric material. ^ C. You are correct. ^ D. Sorry! Couplant is used to improve or permit transmission of ultrasound. 74.

@ Ultrasonic testing of material where the search unit is in

direct contact with the material being tested may be: \d | A. Straight beam testing | B. Surface wave testing | C. Angle beam testing | D. All of the above ^ A. You are partially correct, but surface wave and angle beam testing could also be done. ^ B. You are partially correct, but straight beam and angle beam testing could also be done. ^ C. You are partially correct, but straight beam and surface beam testing could also be done. ^ D. You are correct. 75.

@ An advantage of using lithium sulfate in search units it that:

\b | A. It is one of the most efficient generators of ultrasonic energy. | B. It is one of the most efficient receivers of ultrasonic

energy. | C. It is insoluble. | D. It can withstand temperatures as high as 700 degrees celsius. ^ A. Barium titanate is the most efficient generator. ^ B. You are correct. ^ C. Most piezoelectric crystals are insoluble. (i.e. do not dissolve in water or couplant.) ^ D. None of the crystals can withstand such high temperature. 76.

@ Which of the following search units would contain the thinnest

quartz crystal? \d | A. A 1-MHz search unit | B. A 5-MHz search unit | C. A 15-MHz search unit | D. A 25-MHz search unit ^ A. Crystal thickness is inversely proportional to frequency. ^ B. Crystal thickness is inversely proportional to frequency. ^ C. Crystal thickness is inversely proportional to frequency. ^ D. You are correct. 77.

@ A 25-megahertz search unit would most likely be used during:

\b | A. Straight beam contact testing. | B. Immersion testing.

| C. Angle beam contact testing. | D. Surface wave contact testing. ^ A. In contact testing frequencies, up to 10 MHz are normally used. ^ B. You are correct. ^ C. In angle beam contact testing frequencies up to 10 MHz are normally used. ^ D. In surface wave testing, frequencies up to 10 MHz are normally used. 78.

@ The amount of beam divergence from a crystal is primarily

dependent on the: \c | A. Type of test | B. Tightness of crystal backing in the search unit | C. Frequency and crystal size | D. Pulse length ^ A. No, relation between beam angle of divergence is determined from wavelength divided by crystal diameter. ^ B. No, relation between beam angle of divergence is determined from wavelength divided by crystal diameter. ^ C. Outstanding! ^ D. No, relation between beam angle of divergence is determined from wavelength divided by crystal diameter. 79.

@ When an ultrasonic beam passes through the interface between two

dissimilar materials at an angle, a new angle of sound travel takes place in the second material due to: \d | A. Attenuation | B. Rarefaction | C. Compression | D. Refraction ^ A. No, attenuation depends on frequency of testing. ^ B. No, rarefaction and compression describe the way in which longitudinal waves propagate. ^ C. No, rarefaction and compression describe the way in which longitudinal waves propagate. ^ D. You've got it. 80.

@ The velocity of surface waves is approximately ________ the

velocity of shear waves in the same material. \d | A. Two times | B. Four times | C. One-half | D. Nine-tenths ^ A. No, surface waves travel slower than shear waves. ^ B. No, surface waves travel slower than shear waves. ^ C. No, but you are close. ^ D. Outstanding!

81.

@ Under most circumstances, which of the following frequencies

would result in the best resolving power? \d | A. 1 megahertz | B. 5 megahertz | C. 10 megahertz | D. 25 megahertz ^ A. No, resolution is directly proportional to frequency. ^ B. No, resolution is directly proportional to frequency. ^ C. No, resolution is directly proportional to frequency. ^ D. You're right. 82.

@ Which of the following materials of the same alloy is most likely

to produce the greatest amount of sound attenuation over a given distance? \b | A. A hand forging | B. A coarse grained casting | C. An extrusion | D. The attenuation is equal in all materials ^ A. No, the closer the grain particles, the smaller the attenuation. ^ B. Absolutely right. ^ C. No, the closer the grain particles, the smaller the attenuation.

^ D. No, this is incorrect. It depends on the material and how it was fabricated. 83.

@ In contact testing, the entry surface indication is sometimes

referred to as: \c | A. The initial pulse | B. The "main bang" or transmitter pulse | C. Both A and B | D. None of the above ^ A. Even though this is one answer, there is also another name for it. ^ B. Even though this is one answer, there is also another name for it. ^ C. Outstanding! ^ D. No. All choices listed are at least partially correct. 84.

@ A screen pattern containing a large number of low-level

indications (often referred to as "hash") could be caused by: \c | A. A crack | B. A large inclusion | C. Coarse grained material | D. A gas pocket ^ A. No, a crack should give a single, relatively large, indication.

^ B. No, a large inclusion should give a single, relatively large, indication. ^ C. That is correct. ^ D. No, a gas pocket should give a single, relatively large, indication. 85.

@ A test method employing two separate search units on opposite

surfaces of the material being tested is called: \c | A. Contact testing | B. Surface wave testing | C. Through-transmission testing | D. Lamb wave testing ^ A. No, in contact testing, a search unit is in contact with the material. ^ B. No, in surface wave testing, if two search units are used, they will both be on the same side. ^ C. Absolutely right. ^ D. No, in Lamb wave testing, if two search units are used, they will both be on the same side. 86.

@ The number of complete waves which pass a given point in a

given period of time (usually one second) is referred to as the: \c | A. Amplitude of a wave motion | B. Pulse length of a wave motion

| C. Frequency of a wave motion | D. Wavelength of a wave motion ^ A. No, for measuring amplitude, you do not count the number of waves. ^ B. No, for measuring pulse length, you do not count the number, but the duration. ^ C. Outstanding! ^ D. No, although you are close, the units being asked are per second. Wavelength has units of distance. 87.

@ The boundary between two different materials which are in contact

with each other is called: \c | A. A rarefactor | B. A refractor | C. An interface | D. A marker ^ A. Sorry! Your answer is incorrect. ^ B. Sorry! Your answer is incorrect. ^ C. You've got it. ^ D. Sorry! Your answer is incorrect. 88.

@ When the motion of the particles of a medium is parallel to the

direction of propagation, the wave being transmitted is called a: \a | A. Longitudinal wave

| B. Shear wave | C. Surface wave | D. Lamb wave ^ A. Excellent ^ B. No, particle motion is perpendicular to the direction of propagation. ^ C. No, for surface waves, particle motion is elliptical. ^ D. No, for lamb waves, particle motion is quite complex. 89.

@ When the motion of the particles of a medium is transverse to

the direction of propagation, the wave being transmitted is called a: \b | A. Longitudinal wave | B. Shear wave | C. Surface wave | D. Lamb wave ^ A. No, for longitudinal waves, particle motion is parallel to the direction of propagation. ^ B. You've got it. ^ C. No, for surface waves, particle motion is elliptical. ^ D. No, for lamb waves, particle motion is quite complex. 90.

@ "25 million cycles per second" can also be stated as:

\c | A. 25 kilohertz

| B. 2500 kilohertz | C. 25 megahertz | D. 25 microhertz ^ A. "Kilo" means thousand. i.e. 25 KHz = 25000 cycles per second. ^ B. "Kilo" means thousand. i.e. 2500 KHz = 2500000 cycles per sec. 2.5 MHz where M = Mega = Million. ^ C. Absolutely right. ^ D. "micro" means 1 exp -6. (.000001) This selection is irrelevant. 91.

@ Moving a search unit over a test surface either manually or

automatically is referred to as: \a | A. Scanning | B. Attenuating | C. Angulating | D. Resonating ^ A. Super ^ B. No, choice b is wrong. Try again. ^ C. No, choice c is wrong. Try again. ^ D. No, choice d is wrong. Try again. 92.

@ A term used in ultrasonics to express the rate at which sound

waves pass through various substances is: \b

| A. Frequency | B. Velocity | C. Wave length | D. Pulse length ^ A. No, frequency is number of oscillations per second. ^ B. Outstanding! ^ C. No, units of wavelength are same as that of distance. The question is asking for the rate. ^ D. No, units of pulse length are second. 93.

@ When a vertical indication has reached the maximum signal height

which can be displayed or viewed on the CRT of an ultrasonic instrument, the indication is said to have reached its: \c | A. Distance-amplitude height | B. Absorption level | C. Vertical level | D. Limit to resolution ^ A. Sorry! This choice is incorrect. ^ B. No, in UT what does absorption level mean? Think harder ^ C. You are correct. ^ D. No, resolution is related to pulse duration and beam width. 94.

@ An ultrasonic testing technique in which the transducer element

is not parallel to the test surface is called: \a

| A. Angle beam testing | B. Immersion testing | C. Contact testing | D. Through-transmission testing ^ A. You've got it. ^ B. No, in immersion testing part, transducer is submerged in a liquid. Element may or may not be at an angle. ^ C. No, contact testing includes straight and angle beam testing. ^ D. No, in through-transmission, transducers are on opposite sides of the material. 95.

@ Most commercial ultrasonic testing is accomplished using

frequencies between: \b | A. 1 and 25 kilohertz | B. 0.2 and 25 megahertz | C. 1 and 1,000 kilohertz | D. 15 and 100 megahertz ^ A. No, this is not even in the ultrasonic range. You can only hear up to 20 KHz frequency range. ^ B. You are correct. ^ C. No, you are closer towards the low frequency end. ^ D. No, this is mostly used for NDT research. 96.

@ In an A-scan presentation, the horizontal base line represents

the: \c | A. Amount of reflected ultrasonic sound energy | B. Distance traveled by the search unit | C. Elapsed time or distance | D. None of the above ^ A. No, this is not on horizontal baseline but on the vertical. ^ B. No, in A-scan either you see amount of reflected energy or elapsed time or elapsed distance. ^ C. You are absolutely correct. ^ D. No, there is a correct answer for this question. 97.

@ Which of the following test frequencies would generally provide

the best penetration in a 12-inch thick specimen of coarse- grained steel? \a | A. 1.0 MHz | B. 2.25 MHz | C. 5.0 MHz | D. 10 MHz ^ A. Outstanding! ^ B. No, lower the frequency, the higher the penetration. ^ C. No, lower the frequency, the higher the penetration. ^ D. No, the lower the frequency, the higher the penetration. 98.

@ In a basic ultrasonic test pattern (A-scan) for contact testing,

the initial pulse (assume no sweep delay is used): \a | A. Is the high indication on the extreme left side of the screen that represents the entry surface of the inspected part. | B. Is the first pulse that occurs near the right side of the screen and represents the opposite boundary of the inspected part. | C. Is an indication that appears and disappears during screening. | D. Is always the second pulse from the left on the viewing screen. ^ A. Excellent! ^ B. No, this is back surface reflection. ^ C. No, defect signals appear and disappear. Initial pulse is always there. ^ D. Sorry! Your answer is incorrect. 99.

@ An ultrasonic test using a straight beam contact search unit

is being conducted through the thickness of a flat part such as a plate. This test should detect: \a | A. Laminar-type flaws with major dimensions parallel to the rolled surface. | B. Transverse-type flaws with major dimensions at right angles

to the rolled surface. | C. Radial flaws with major dimensions along length, but radially oriented to the rolled surface. | D. None of the above. ^ A. Super! ^ B. No, the golden rule of ultrasonics, "Always impinge the flaw so that maximum energy is reflected back, i.e. perpendicular to flow. ^ C. No, the golden rule of ultrasonics, "Always impinge the flaw so that maximum energy is reflected back,i.e. perpendicular to flow. ^ D. Sorry! Please try again. 100.

@ In ultrasonic testing, a liquid coupling medium between the

crystal surface and the part surface is necessary because: \b | A. Lubricant is required to minimize wear on the crystal surface. | B. An air interface between the crystal surface and the part surface would almost completely reflect the ultrasonic vibrations. | C. The crystal will not vibrate if placed directly in contact with the surface of the part being inspected. | D. The liquid is necessary to complete the electrical circuit in the search unit.

^ A. No, it is important to maximize coupling. ^ B. Excellent! ^ C. Not correct. Only energy will not be transmitted into the part. ^ D. Incorrect. Only energy will not be transmitted into the part. 101.

@ Entry surface resolution is a characteristic of an ultrasonic

testing system which defines its ability to: \d | A. Detect discontinuities oriented in a direction parallel to the ultrasonic beam. | B. Detect discontinuities located in the center of a forging containing a fine metallurgic structure. | C. Detect minute surface scratches. | D. Detect discontinuities located just beneath the entry surface in the part being tested. ^ A. No, entry surface resolution is related to "main bang" and its duration. ^ B. No, entry surface resolution is related to "main bang" and its duration. ^ C. No, entry surface resolution is related to "main bang" and its duration. ^ D. Super! 102.

@ During ultrasonic testing by the immersion method, it is

frequently necessary to angulate the search unit when a discontinuity is located in order to: \b | A. Avoid a large number of back reflections that could interfere with a normal test pattern. | B. Obtain a maximum response if the discontinuity is not originally oriented perpendicular to the ultrasonic beam. | C. Obtain the maximum number of entry surface reflections. | D. Obtain a discontinuity indication of the same height as the indication from the flat-bottomed hole in a reference block. ^ A. No, this could be done by adjusting time base, sweep control etc. ^ B. Super! You are absolutely correct. ^ C. Sorry! Think again. ^ D. No, in UT, you always try to get maximum amplitude signal. 103. @ All other factors being equal, which of the following modes of vibration has the greatest velocity? \d | A. Shear wave | B. Transverse wave | C. Surface wave | D. Longitudinal wave

^ A. No, compressional waves travel the fastest. ^ B. No, compressional waves travel the fastest. ^ C. No, compressional waves travel the fastest. ^ D. You are absolutely correct. 104.

@ On the area-amplitude ultrasonic standard test blocks, the

flat- bottomed holes in the blocks are: \b | A. All of the same diameter | B. Different in diameter, increasing by 1/64-inch increments from the No. "1" block to the No. "8" block. | C. Largest in the No. "1" block and smallest in the No. "8" block. | D. Drilled to different depths from the front surface of the test block. ^ A. No, they have different diameters. ^ B. You've got it. ^ C. No, this is incorrect. ^ D. No, they have different diameters. 105.

@ In immersion testing, verification that the search unit is

normal to a flat entry surface is indicated by: \a | A. Maximum reflection from the entry surface | B. Elimination of water multiples | C. Proper wavelength

| D. Maximum amplitude of the initial pulse ^ A. Excellent!! You are correct. ^ B. No, by eliminating water multiples you cannot be assured that the search unit is normal. ^ C. No, this does not assure normality. ^ D. No, this does not assure normality. 106.

@ Sound waves of a frequency beyond the hearing range of the

human ear are referred to as ultrasonic waves or vibrations, and the term embraces all vibrational waves of frequency greater than approximately: \a | A. 20,000 hertz | B. 2 megahertz | C. 2 kilohertz | D. 200 kilohertz ^ A. Super! You are right. ^ B. No, ultrasonic range starts at lower frequency. ^ C. No, this is within the hearing range. ^ D. No, ultrasonic range starts at lower frequency. 107.

@ The velocity of sound waves is primarily dependent on:

\c | A. The pulse length | B. The frequency | C. The material in which the sound is being transmitted and

the mode of vibration | D. None of the above. ^ A. No, velocity has nothing to do with the pulse length. ^ B. No, velocity is independent of frequency and depends on modulus and density. ^ C. Outstanding! ^ D. No, think again. 108.

@ A disadvantage of using natural quartz crystals in a search

unit is that: \b | A. It will dissolve in water. | B. It is the least effective generator of ultrasonic energy of all commonly used materials. | C. It is mechanically and electrically unstable. | D. It easily loses it operating characteristics as it ages. ^ A. No, this is not a problem. How do you make the best transducers. ^ B. You've got it. ^ C. No, generation and reception are the main concerns. ^ D. No, generation and reception are the main concerns. 109.

@ An advantage of using a ceramic transducer in search units is

that: \a | A. It is one of the most efficient generators of ultrasonic

energy. | B. It is one of the most efficient receivers of ultrasonic energy. | C. It has a very low mechanical impedance. | D. It can withstand temperatures as high as 700 degrees celsius. ^ A. Absolutely correct. ^ B. No, quartz is a better receiver than many ceramic transducers. ^ C. No, generation and reception are most important factors. ^ D. Sorry! Please try again. 110.

@ The primary purpose of reference blocks is to:

\c | A. Aid the operator in obtaining maximum back reflections. | B. Obtain the greatest sensitivity possible from an instrument. | C. Obtain a common reproducible signal. | D. None of the above. ^ A. No, reference blocks are used to establish some sort of reference comparison. ^ B. No, reference blocks are used to establish some sort of reference comparison. ^ C. You are absolutely correct. ^ D. No, reference blocks are used to establish some sort of reference comparison.

111.

@ When testing by the surface wave method, patches of oil or dirt

on the surface may: \d | A. Block the progress of all sound. | B. Attenuate the sound. | C. Have no effect on the test. | D. Cause both an attenuation of sound and indications on the screen. ^ A. Yes, but shouldn't there be an indication on screen because of patches of oil or dirt. ^ B. Close, but there is more to it. ^ C. No, in surface wave testing the surface must be clean. ^ D. Super! You are absolutely correct. 112.

@ In immersion testing, the most commonly used couplant is:

\a | A. Water | B. Oil | C. Glycerine | D. Alcohol ^ A. Excellent ^ B. No, the choice of couplant is based on many factors including affect on material, wetting properties, etc. ^ C. No, the choice of couplant is based on many factors including affect on material, wetting properties, etc.

^ D. No, the choice of couplant is based on many factors including affect on material, wetting properties, etc. 113.

@ Which of the following frequencies will produce the shortest

wavelength pulse? \b | A. 1.0 megahertz | B. 25 megahertz | C. 10 megahertz | D. 5 megahertz ^ A. No, since c=frequency x wavelength, the larger the frequency, the smaller the wavelength. ^ B. You've got it. ^ C. No, since c=freq x wavelength, the higher the frequency, the smaller the wavelength. ^ D. No, since c=freq x wavelength, the higher the frequency, the smaller the wavelength. 114.

@ The angle of incidence is:

\c | A. Greater than the angle of reflection | B. Less than the angle of reflection | C. Equal to the angle of reflection | D. Not related to the angle of reflection ^ A. No, this is not possible according to Snell's law. ^ B. No, this is not possible according to Snell's law.

^ C. You're right. ^ D. No, the angle of reflection and the angle of incidence are very much related. 115.

@ On many ultrasonic testing instruments, an operator conducting

an immersion test can remove that portion of the screen presentation that represents water distance by adjusting a: \c | A. Pulse length control. | B. Reject control. | C. Sweep delay control. | D. Sweep length control. ^ A. No, pulse length control will change pulse length, it cannot remove anything from the screen. ^ B. No, the reject control is set up on the basis of signal amplitude. ^ C. Absolutely correct. ^ D. No, but you are close. Sweep length will change number of water multiples. 116.

@ "100,000 cycles per second" can be written:

\b | A. 10 kilohertz | B. 100 kilohertz | C. 100 MHz | D. 0.1 kilohertz.

^ A. "Kilo" means one thousand. ^ B. Outstanding ^ C. No, One Megahertz means one million cycles/second. ^ D. No, the prefix kilo means one thousand. 117.

@ A search unit with a frequency greater than 10 MHz will most

likely be used during: \d | A. A straight beam contact test of aluminum ingot | B. An angle beam contact test of a steel pipe | C. A surface wave contact test of a metallic plate | D. An immersion test ^ A. No, immersion tests are normally of higher frequency than contact testing. ^ B. No, immersion tests are normally of higher frequency than angle beam testing. ^ C. No, immersion tests are normally of higher frequency than surface wave testing. ^ D. You've got it. 118. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxx 119. ULTRASONICS TESTING LEVEL II 120.

@ 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! 121.

@ 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. 122.

@ 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. 123.

@ 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. 124.

@ In an ultrasonic instrument, the number of pulses produced by

an instrument in a given period of time is known as the: \d |A. Pulse length of the instrument. |B. Pulse recovery time. |C. Frequency. |D. Pulse repetition rate. ^A. No. Look at the units. ^B. No. Look at the units. ^C. Sorry! Frequency is related to the transducer. ^D. You are correct. 125.

@ In a basic pulse-echo ultrasonic instrument, the component

that coordinates the action and timing of other components is called a: \d |A. Display unit or CRT. |B. Receiver. |C. Marker circuit or range marker circuit. |D. Synchronizer, clock, or timer. ^A. Sorry! Information is displayed on CRT. ^B. Sorry! Receiver amplifies a signal. ^C. Sorry! Try again. ^D. Excellent!

126.

@ In a basic pulse-echo ultrasonic instrument, the component that

produces the voltage that activates the search unit is called: \c |A. An amplifier |B. A receiver |C. Pulser |D. A synchronizer ^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. 127.

@ In a basic-pulse-echo ultrasonic instrument, the voltage

producing component which activates the search unit is called: \a |A. Sweep circuit |B. Receiver |C. Pulser |D. Synchronizer ^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. 128.

@ In a basic pulse-echo ultrasonic instrument, the component

that produces visible signals on the CRT which are used to measure distance is called a: \b |A. Sweep circuit |B. Marker circuit |C. Receiver circuit |D. Synchronizer ^A. Sorry! Try again. ^B. You've got it. ^C. Sorry! Receiver amplifies the signal. ^D. Sorry! The synchronizer coordinates action and timing. 129.

@ 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. 130.

@ The cathode ray tube screen will display a plan view of the part

outline and defects when using: \d |A. Automatic read-out equipment. |B. An A-scan presentation. |C. A B-scan presentation. |D. A C-scan presentation. ^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. 131.

@ The incident angles at which 90 degrees refraction of

longitudinal and shear waves occurs are called: \b |A. The normal angles of incidence. |B. The critical angles. |C. The angles of maximum reflection. |D. None of the above. ^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. 132.

@ Compression waves whose particle displacement is parallel to

the direction of propagation are called: \a

|A. Longitudinal waves |B. Shear waves |C. Lamb waves |D. Rayleigh waves ^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. 133.

@ Which of the following modes of vibration are quickly damped

out when testing by the immersion method? \d |A. Longitudinal waves |B. Shear waves |C. Transverse waves |D. Surface waves ^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. 134. \b

@ 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 degrees to the direction of beam propagation. ^A. No, this defines the longitudinal waves. ^B. You are correct. ^C. No, this defines the surface waves. ^D. Sorry! Please try again. 135.

@ In contact testing, shear waves can be induced in the test

material by: \d |A. Placing a 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. 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.

136.

@ As frequency increases in ultrasonic testing, the angle of

beam divergence of a given diameter crystal: \a |A. Decreases. |B. Remains unchanged. |C. Increases. |D. Varies uniformly through each wavelength. ^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. 137.

@ Which of the following is not an advantage of contact

ultrasonic search units(probes) adapted with lucite shoes? \c |A. Eliminates most of the crystal wear. |B. Permits adaptation to curved surfaces. |C. Decreases sensitivity. |D. Allows ultrasound to enter a part's 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. 138.

@ In which medium listed below would the velocity of sound be

lowest? \a |A. Air |B. Water |C. Aluminum |D. Stainless steel ^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. 139.

@ A longitudinal ultrasonic wave is transmitted from water into

steel at an angle of 5 degrees from the normal. In such a case the refracted angle of the transverse wave is: \a |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. You are right on target.

^B. No, apply Snell's law. ^C. No, think about Snell's law. ^D. No, you are incorrect. 140.

@ 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. 141.

@ In steel, the velocity of sound is greatest in which of the

following modes of vibration? \a | A. Longitudinal | B. Shear | C. Surface waves. | D. Sound velocity is identical in all modes, in a given material. ^ 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. 142.

@ The acoustic impedance is:

\b | 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. Sorry! Acoustic impedance is used for calculating transmission and reflection of ultrasound. ^ B. You are right on target. ^ C. Sorry! Acoustic impedance is used for calculating transmission and reflection of ultrasound. ^ D. Sorry! Acoustic impedance is used for calculating transmission and reflection of ultrasound. 143.

@ Thin sheet may be inspected with the ultrasonic wave directed

normal to the surface by observing: \b | A. The amplitude of the front surface reflection. | B. The multiple reflection pattern. | C. All front surface reflections | D. None of the above. ^ A. No, front surface signal will have a considerable dead

zone. ^ B. Outstanding ^ C. Sorry! Try again. ^ D. No, there is a correct answer. 144.

@ 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: \c | A. Schematic diagram | B. Blueprint | C. Block diagram | D. None of the above ^ 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. 145.

@ A hole produced during the solidification of metal due to

escaping gases is called: \d | A. A burst | B. A cold shut | C. A flaking | D. A blow hole ^ A. Sorry! You've answered incorrectly.

^ B. Sorry! A cold shut is caused by splashing, singing, interrupted pouring etc. ^ C. Sorry! You've answered incorrectly. ^ D. You are right.

@ 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: \b | A. A burst | B. A cold shut. | C. Flaking | D. A blow hole ^ A. Sorry! You've answered incorrectly. ^ B. Great ^ C. Sorry! Your answer is wrong. ^ D. No, blow holes are produced by escaping gases. 146.

@ The ratio between the wave speed in one material and the wave

speed in a second material is called: \d | A. The acoustic impedance of the interface | B. Young's modulus | C. Poisson's ratio

| D. The index of refraction. ^ A. Sorry, your answer is incorrect. ^ B. Sorry! Young's modulus is a ratio of stress and strain. ^ C. No, Poisson's ratio is a ratio of strains. ^ D. You got it. 147.

@ The expansion and contraction of a magnetic material under the

influence of a changing magnetic field is referred to as: \c | A. Piezoelectricity | B. Refraction. | C. Magnetostriction | D. Rarefaction ^ A. Piezoelectricity is due to pressure or stress. ^ B. No, refraction is associated with transmission of sound waves through a layered media. ^ C. You are correct. ^ D. No, rarefaction is associated with the way longitudinalwave propagates through a material. 148.

@ The ratio of stress to strain in a material within the elastic

limit is called: \c | A. Young's modulus | B. The Modulus of elasticity | C. Both A and B

| D. The index of refraction ^ A. Yes, but another choice is also correct. ^ B. Yes, but another choice is also correct. ^ C. You are right on target. ^ D. Sorry! Index of refraction is ratio of wave speeds in two adjacent materials. 149.

@ A point, line, or surface of a vibrating body marked by absolute

or relative freedom from vibratory motion is referred to as: \a | A. A node | B. An antinode | C. Rarefaction | D. Compression ^ A. You are absolutely right. ^ B. Sorry! Amplitude of vibratory motion is largest in antinodes. ^ C. Sorry! A longitudinal wave propagates by means of "compression and rarefaction of material particles. ^ D. Sorry! A longitudinal wave propagates by means of "compression and rarefaction of material particles. 150.

@ 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: \b | A. A Y-cut crystal

| B. A X-cut crystal | C. A Z-cut crystal | D. A ZY-cut crystal ^ A. No, this type of cut generates L-waves. ^ B. You are correct. ^ C. Sorry! Your answer is incorrect. ^ D. Sorry! Your answer is incorrect. 151.

@ The equation describing wavelength in terms of velocity and

frequency is: \c | A. Wavelength = Velocity x Frequency | B. Wavelength = Z (Frequency x Velocity | C. Wavelength = Velocity / Frequency | D. Wavelength=Frequency + Velocity ^ A. No. Check units to find the correct relationship. ^ B. No. Check units to find the correct relationship. ^ C. Yes, you got it. ^ D. No. Check units to find the correct relationship. 152.

@ Which of the following can occur when an ultrasonic beam

reaches the interface of two dissimilar materials? \d | A. Reflection | B. Refraction | C. Mode conversion

| D. All of the above ^ 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 153.

@ Of the piezoelectric materials listed below, the most

efficient sound transmitter is: \c | A. Lithium sulfate | B. Quartz | C. Barium titanate | D. Silver oxide ^ A. No, this is the best receiver. ^ B. Sorry! Try again. ^ C. You got it. ^ D. Incorrect, silver oxide is not a piezoelect!Unexpected End of Formula 154.

@ Of the piezoelectric materials listed below, the most

efficient sound receiver is: \a | A. Lithium sulfate | B. Quartz | C. Barium titanate | D. Silver oxide. ^ 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. 155.

@ The most commonly used method of producing shear waves in a

test part when inspecting by the immersion method is: \d | A. By transmitting longitudinal waves into a part in a direction 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. ^ 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. 156.

@ Beam divergence is a function of the dimensions of the crystal

and the wavelength of the beam transmitted through a medium, and it: \a | A. increases if the frequency or crystal diameter is decreased. | B. decreases if the frequency or crystal diameter is decreased. | C. increases if the frequency is increased and crystal diameter decreased.

| D. decreases if the frequency is increased and crystal diameter is decreased. ^ 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). 157. @ The wavelength of an ultrasonic wave is: \b | 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 the velocity and frequency. ^ 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. 158.

@ The fundamental frequency of a piezoelectric crystal is

primarily a function of: \c | A. the length of the applied voltage pulse. | B. the amplifying characteristics of the pulse amplifier in

the instrument. | C. the thickness of the crystal. | D. none of the above. ^ A. No, it is related to a transducer dimension. ^ B. No, it is related to a transducer dimension. ^ C. You are correct. ^ D. No, there is a correct answer. 159.

@ Acoustic velocities are primarily described by:

\c | A. density | B. elasticity | C. both A and B | D. acoustic impedance ^ A. Yes, but there is another factor. ^ B. Yes, but there is another factor. ^ C. Outstanding ^ D. Sorry! Acoustic impedance determines transmission and reflection of sound. 160.

@ Inspection of castings is often impractical because of:

\b | A. extremely small grain structure. | B. coarse grain structure. | C. uniform flow lines. | D. uniform velocity of sound.

^ A. Incorrect, it is easy to inspect small grain structure materials ^ B. You are absolutely right. ^ C. Sorry! Attenuation determines inspectability. ^ D. Sorry, your answer is incorrect. 161.

@ Lamb waves may be used to inspect:

\d | A. forgings | B. bar stock | C. ingots | D. thin sheet ^ A. No, Lamb waves do not travel in thick material. ^ B. No, Lamb waves do not travel in thick material. ^ C. No, Lamb waves do not travel in thick material. ^ D. You are correct. 162.

@ The resolving power of a search unit is directly proportional

to its: \b | A. diameter | B. band width | C. pulse repetition | D. none of the above ^ A. Sorry! Diameter does not directly influence resolution. ^ B. Great

^ C. No, resolution is dependent on pulse duration and frequencies. ^ D. Sorry! There is a correct answer. 163.

@ In the basic pulse-echo instrument, the synchronizer, clock or

timer circuit will determine the instrument's: \c | A. pulse length | B. gain | C. pulse repetition rate | D. sweep length ^ A. No, transducer and excitation pulse determine pulse length. ^ B. No, excitation pulse voltage determines gain. ^ C. You got it. ^ D. Sorry! Your answer is incorrect. 164.

@ The primary requirement of a paintbrush transducer is that:

\b | 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 .01%. | D. the overall length not exceed 3 inches. ^ A. No, paintbrush transducer has only one crystal.

^ B. Outstanding ^ C. No, paintbrush transducer has only one crystal. ^ D. Sorry! Your answer is incorrect. 165.

@ Heat conduction, viscous friction, elastic hysteresis, and

scattering are four different mechanisms which lead to: \a | A. attenuation | B. refraction | C. beam spreading | D. saturation. ^ A. You got it. ^ B. No, sound propagation at an angle through different media causes refraction. ^ C. Sorry! Beam spread is a function of wavelength and transducer diameter. ^ D. Sorry! This choice is incorrect. 166.

@ Since the velocity of sound in aluminum is approximately 245,000

in/sec, how long does it take for sound to travel through 1 inch of aluminum? \b | A. 1/8 second | B. 4 microseconds | C. 4 milliseconds | D. 1/4 X 100000 seconds

^ A. No, divide distance by speed. ^ B. You are right on the mark. ^ C. No, check your math. ^ D. No, divide distance by speed. 167.

@ When testing a part with a rough surface, it is generally

advisable to use: \a | A. a lower frequency search unit and a more viscous couplant than is used on parts with a smooth surface. | B. a higher frequency search unit and a more viscous couplant than is used on parts with a smooth surface. | C. a higher frequency search unit and a less viscous couplant than is used on parts with a smooth surface. | D. a lower frequency search unit and a less viscous couplant than is used on parts with a smooth surface. ^ A. You are correct. ^ B. No, it will cause too much scattering. ^ C. No, the air bubbles may cause problems. ^ D. No, air bubbles may cause problems. 168.

@ Reflection indications from a weld area being inspected by the

angle-beam technique may represent: \d | A. Porosity | B. Cracks

| C. Weld bead | D. All three of the above ^ A. No, there are several other reflector types which can also give indications. ^ B. No, there are several other reflector types which can also give indications. ^ C. No, there are several other reflector types which can also give indications. ^ D. You are correct. @ In an A-scan presentation, the horizontal line formed by the uniform and repeated movement of an electron beam across the fluorescent screen of a cathode ray tube is called: \b | A. A square wave pattern. | B. A sweep line. | C. A marker pattern. | D. None of the above. ^ A. Sorry! This choice is incorrect. ^ B. Excellent! You are exactly right. ^ C. Sorry! This choice is incorrect. ^ D. No, there is a correct answer. @ Which of the following frequencies would probably result in the greatest amount of attenuation losses? \d

| A. 1.0 megahertz. | B. 2.25 megahertz. | C. 5 megahertz. | D. 10 megahertz. ^ A. No, attenuation losses are directly proportional to frequency. ^ B. No, attenuation losses are directly proportional to frequency. ^ C. No, attenuation losses are directly proportional to frequency. ^ D. Super @ In general, which waves will travel around gradual curves with little or no reflection from the curve? \b | A. Transverse waves. | B. Surface waves. | C. Shear waves. | D. Longitudinal waves. ^ 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. 169.

@ To evaluate and accurately locate discontinuities after

scanning a part with a paintbrush transducer, it is generally

necessary to use a: \a | A. Search unit with a smaller crystal. | B. Scrubber. | C. Grid map. | D. Crystal collimator. ^ 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 @ When using two separate search units (one a transmitter, the other a receiver), the most efficient combination would be: \b | A. A quartz transmitter and a barium titanate receiver. | B. A barium titanate transmitter and a lithium sulfate receiver. | C. A lithium sulfate transmitter and a barium titanate receiver. | D. A barium titanate transmitter and a quartz receiver. ^ 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.

170.

@ In immersion testing, the accessory equipment to which the

search cable and the search unit are attached is called a: \d | A. Crystal collimator. | B. Scrubber. | C. Jet-stream unit. | D. Search tube or scanning tube. ^ A. Sorry! This choice is incorrect. ^ B. Sorry! This choice is incorrect. ^ C. Sorry! This choice is incorrect. ^ D. You are correct. @ In general, discontinuities in wrought products tend to be oriented: \b | 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. No, the key words are "wrought products." ^ B. Super ^ C. No. The key words are "wrought products." ^ D. No. The key words are "wrought products." @ In immersion testing irrelevant or false indications caused by contoured surfaces are likely to result in a:

\a | A. Broad-based indication. | B. Peaked indication. | C. "Hashy" signal. | D. Narrow-based indication. ^ A. You are correct. ^ B. Sorry! Curved surface tends to increase pulse duration. ^ C. No, "hashy" signal is caused by electronic or material noise. ^ D. No, curved surface tends to increase pulse duration. @ In contact testing, defects near the entry surface cannot always be detected because of: \c | A. The far-field effect. | B. Attenuation. | C. The dead zone. | D. Refraction. ^ A. No, the far-field effect does not come into play near the entry surface in contact testing. ^ B. Sorry! Attenuation near the entry surface should not be a major factor. ^ C. You are correct. ^ D. Sorry, this answer is incorrect. @ 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? \b | A. A scrubber. | 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 171.

| A. One inch.

| B. Four inches. | C. One wavelength. | D. Four wavelengths. ^ A. No, the surface waves do not penetrate much into the material. ^ B. No, the surface waves do not penetrate much into the material. ^ C. Excellent!! You are correct. ^ D. No, the surface waves do not penetrate much below one wavelength. @ 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 one inch of water for every: \b | A. Two inches of aluminum. | B. Four inches of aluminum. | C. Six inches of aluminum. | D. Eight inches of aluminum. ^ A. No, the water path should be at least four times smaller

than the test specimen. ^ B. You are correct. ^ C. No, the water path should be at least four times smaller than the test specimen. ^ D. No, the water path should be at least four times smaller than the test specimen. @ Increasing the length of the pulse used to activate the search unit will: \a | A. Increase the strength of the ultrasound but decrease the resolving power ofthe 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. You are correct. ^ B. No, the pulse length is increased, therefore resolving power is decreased. ^ C. No, the pulse length is increased, therefore resolving power is decreased. ^ D. No, the penetration is increased. @ Of the following sound wave modes, which one has multiple or varying wave velocities? \d | A. Longitudinal waves

| B. Shear waves | C. Transverse waves | D. Lamb waves ^ A. No, longitudinal waves have one velocity in any given material. ^ B. No, shear waves have one velocity in any given material. ^ C. No, transverse waves have one velocity in any given material. ^ D. You are correct. @ Which of the following would be considered application(s) of ultrasonic techniques? \d | A. Determination of a material's elastic modulus | B. Study of a material's metallurgical structure | C. Measurement of a material's thickness | D. All of the above. ^ A. True, but you can do much more with ultrasonics. ^ B. True, but you can do much more with ultrasonics. ^ C. True, but you can do much more with ultrasonics. ^ D. Very good. You are absolutely correct. @ The only significant sound wave mode that will travel through a liquid is: \b | A. Shear

| B. Longitudinal | C. Surface | D. Rayleigh ^ A. No, liquids do not support shear waves. ^ B. You are correct. ^ C. No, Liquids do not support surface waves. ^ D. No, liquids do not support Rayleigh waves. @ The acoustic impedance of a material is used to: \c | A. Determine the angle of refraction at an interface. | B. Determine the attenuation within the material. | C. Find the amounts of sound energy reflected and refracted through an interface. | D. Determine the beam spread within the material. ^ A. No, velocity ratio is used for determining angle of refraction. ^ B. Sorry! Frequency, wavelength, grain size, etc. are used to calculate attenuation. ^ C. You are correct. ^ D. No, wavelength and transducer diameter are needed to calculate beam spread. @ Acoustic energy propagates in different modes. Which of the following represents a mode? \d

| A. Longitudinal wave | B. Shear wave | C. Surface wave | D. All of the above ^ A. Sorry! There are several other modes as well. ^ B. Sorry! There are several other modes as well. ^ C. Sorry! There are several other modes as well. ^ D. You are absolutely correct. @ When angle beam contact testing a test piece, increasing the incident angle until the second critical angle is reached results in: \c | A. Total reflection of a surface wave. | B. 45 degree refraction of the shear wave | C. Production of a surface wave | D. None of the above ^ A. No. What does total reflection mean ^ B. No. Try to apply Snell's law. ^ C. You are correct. ^ D. No. Try to apply Snell's law. @ The simple experiment where a stick in a glass of water appears disjointed at the water surface illustrates the phenomenon of: \c | A. Reflection | B. Magnification

| C. Refraction | D. Diffraction ^ A. No, reflection should not make it appear disjointed. ^ B. No, magnification means to enlarge - It means different from disjointed. ^ C. You are correct. ^ D. Sorry! you've answered incorrectly. @ The crystal thickness and transducer frequency are related. The thinner the crystal: \b | A. The lower the frequency | B. The higher the frequency | C. There is no appreciable effect | D. None of the above ^ A. No, there is an inverse relationship. ^ B. You are correct. ^ C. No, there is an inverse relationship. ^ D. No, there is an inverse relationship. @ The random distribution of crystallographic direction in alloys with large crystalline structure is a factor in determining: \d | A. Acoustic noise levels | B. Selection of test frequency | C. Scattering of sound

| D. All of the above ^ A. True, but there are other considerations as well. ^ B. True, but there are other considerations as well. ^ C. True, but there are other considerations as well. ^ D. You are correct. @ The length of the zone adjacent to a transducer in which fluctuations in sound pressure occur is mostly affected by: \d | A. The frequency of the transducer | B. The diameter of the transducer | C. Scattering of sound | D. Both A and B ^ A. True, but there is another factor too. ^ B. True, but there is another factor too. ^ C. No, scattering of sound is irrelevant here. ^ D. You are correct. @ The differences in signals received from identical reflectors at different material distances from a transducer may be caused by: \d | A. Material attenuation. | B. Beam divergence. | C. Near field effects. | D. All of the above. ^ A. True, but there are other reasons too.

^ B. True, but there are other reasons too. ^ C. True, but there are other reasons too. ^ D. Excellent! You are right. @ It is possible for a discontinuity smaller than the transducer to produce indications of fluctuating amplitude as the search unit is moved laterally if testing is being performed in the: \b | A. Fraunhofer zone. | B. Near field. | C. Snell field. | D. Shadow zone. ^ A. No, signal should remain constant. ^ B. You've got it. ^ C. Sorry! No such thing in UT. ^ D. Sorry, your answer is incorrect. @ In immersion testing, the near field effects of a transducer may be eliminated by: \c | A. Increasing transducer frequency. | B. Use of larger diameter transducer. | C. Using an appropriate water path. | D. Use of a focused transducer. ^ A. No, nearfield distance is increased. ^ B. No, nearfield distance is increased.

^ C. You've got it ^ D. Sorry! This choice is incorrect. @ 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? \c | A. Multiple indications before the first back reflection. | B. Indications from multiple surface reflection. | C. Conversion from the longitudinal mode to shear mode. | D. Loss of front surface indications. ^ A. Not true if the rod is smooth, i.e. no scratches, cracks, etc. ^ B. No. This is not possible. ^ C. Absolutely ^ D. No, this is not possible. @ Where does beam divergence occur? \b | A. Near field. | B. Far field. | C. At the crystal. | D. None of the above. ^ A. No, not in the nearfield. ^ B. That's correct. ^ C. No, it is not at the crystal but away from it.

^ D. No, beam diverges after the Fresnel zone. @ As frequency increases in ultrasonic testing, the angle of beam divergence of a given diameter crystal: \a | A. Decreases | B. Remains unchanged | C. Increases | D. Varies uniformly through each wavelength ^ A. Super! You are correct. ^ B. No, angle of divergence is a function of wavelength/transducer diameter. ^ C. No, angle of divergence is a function of wavelength/transducer diameter. ^ D. No, angle of divergence is a function of wavelength/transducer diameter. @ As the radius of curvature of a curved lens is increased, the focal length of the lens will: \a | A. Increase | B. Decrease | C. Remain the same | D. Be indeterminate unless the frequency is known ^ A. You've got it. ^ B. No, flat surface has infinite radius of curvature.

^ C. No, it will definitely increase or decrease. ^ D. No, it will definitely increase or decrease. @ When examining materials for planar flaws oriented parallel to the part surface, what testing method is most often used? \c | A. Angle beam | B. Through-transmission | C. Straight beam | D. Dual crystal ^ A. No, angle beam testing is most useful when flaw is oriented perpendicular to the part surface. ^ B. No, through-transmission is most useful in highly attenuative materials. ^ C. You've got it. ^ D. No, dual crystal transducer are used when flaw is located close to the surface. @ Rayleigh waves are influenced most by defects located: \c | A. One wavelength below the surface | B. Six wavelengths below the surface | C. Close to or on the surface | D. Three wavelengths below the surface ^ 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. 172.

@ The ratio of the velocity of sound in water compared to that

for aluminum or steel is approximately: \a | A. 1:4 | B. 1:2 | C. 1:8 | D. 1:3 ^ A. You are correct. ^ B. Sorry! This choice is incorrect. ^ C. Sorry! Please try again. ^ D. Sorry! Your answer is incorrect. @ Which of the following scanning methods could be classified as an immersion type test? \d | A. Tank in which the search unit and test piece are immersed | B. Squirter bubbler method in which the sound is transmitted in a column of flowing water | C. Scanning with a wheel-type search unit with the transducer inside a liquid filled tire

| D. All of the above ^ A. True, but there are other set ups as well. ^ B. True, but there are other set ups as well. ^ C. True, but there are other set ups as well. ^ D. That is correct. @ 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 | A. Reduced velocity of sound in water as compared to test specimen. | B. Increased velocity of sound in water as compared to test specimen. | C. Temperature of the water. | D. All of the above. ^ A. Super! You are correct. ^ B. No, velocity of sound in water is lower than test specimen. ^ C. No, velocity of sound in water is lower than test specimen. ^ D. No, velocity of sound in water is lower than test specimen. @ What law can be used to calculate the angle of refraction within a metal for both longitudinal and shear waves? \b | A. Poisson's Ratio Law

| B. Snell's Law | C. Fresnel's Field Law | D. Charles' Law ^ A. Sorry! Please try again. ^ B. You've got it. ^ C. Sorry! Your choice is incorrect. ^ D. Sorry! This choice is incorrect. @ At an interface between two different materials, an impedance difference results in: \c | 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. None of the above ^ A. No, some of it goes into the second material and some is reflected. ^ B. No, it is both transmitted and reflected. ^ C. You are correct ^ D. No, some of it goes into the second material while some of it is reflected. @ When using focused transducers, non-symmetry in a propagated sound beam may be caused by: \d

| A. Backing material variations | B. Lens centering or misalignment | C. Porosity in lenses | D. All of the above ^ A. Yes, but there could also be other causes. ^ B. Yes, but there could also be other causes. ^ C. Yes, but there could also be other causes. ^ D. You are correct. @ Ultrasonic wheel units may be used for which of the following types of examination? \d | A. Straight or longitudinal examination | B. Angle-beam or shear wave examination | C. Surface wave or Rayleigh wave | D. All of the above ^ A. Yes, but other answer choices apply as well. ^ B. Yes, but other answer choices apply as well. ^ C. Yes, but other answer choices apply as well. ^ D. You are correct. @ During straight beam testing, test specimens with non-parallel front and back surfaces can cause: \a | 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. You are absolutely correct. ^ B. Sorry, this is incorrect. Lack of parallelism will affect signal amplitude. ^ C. This is possible but there is a more profound affect on the amplitude. ^ D. No, there is a more profound affect on the amplitude. @ 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. \b | A. Is equal to the time required for the sound to travel through the piece. | B. Is greater than the time required for the sound to travel through the testpiece. | C. Is less than the time required for the sound to travel through the test piece. | D. None of the above. ^ A. Yes, but this will cause a lot of confusion, since the signals will be superimposed. ^ B. Absolutely right. ^ C. No, this answer is incorrect. ^ D. No, there is a valid answer.

@ In a B-scan display, the length of a screen indication from a discontinuity is related to: \b | 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. Both A and B | D. None of the above ^ A. No, not the length of a screen indication. ^ B. You are right ^ C. Incorrect, inspect choice A again. ^ D. No, there is a valid answer. @ Which circuit triggers the pulser and sweep circuits in an A-scan display? \c | A. Receiver-amplifier | B. Power supply | C. Clock | D. Damping ^ A. No, the receiver-amplifier modifies return signal for display. ^ B. No, this choice is incorrect. ^ C. You are correct.

^ D. No, damping only adjusts excitation pulse width. @ On an A-scan display, the "dead zone," refers to: \c | A. The distance contained within the near field. | B. The area outside the beam spread. | C. The distance covered by the front surface pulse width and recovery time. | D. The area between the near field and the far field. ^ A. Sorry! Generally "dead zone" is much smaller than the nearfield. ^ B. Sorry! "Dead zone" is due to the pulse duration. ^ C. You've got it. ^ D. Sorry! Please try again. @ On an A-scan display, what represents the intensity of a reflected beam? \d | A. Echo pulse width | B. Horizontal screen location | C. Signal brightness | D. Signal amplitude ^ A. Sorry! Please try again. ^ B. Sorry! This gives discontinuity location. ^ C. Sorry! Signal brightness is used in B-scan to represent the intensity of reflected beam.

^ D. You are exactly right. @ Of the following scan types, which one can be used to produce a recording of flaw areas superimposed over a plan view of the test piece? \c | A. A-scan | B. B-scan | C. C-scan | D. D-scan ^ A. No, an A-scan represents the amplitude-distance relationship. ^ B. No, the B-scan represents the cross-sectional view. ^ C. You are correct ^ D. No, there is no such thing as a D-scan. @ In immersion testing in a small tank, a manually operated manipulator is used to: \d | A. Set the proper water path | B. Set the proper transducer angle | C. Set the proper index function | D. Both A and B ^ A. Yes, but it is used to do more than that. ^ B. Yes, but it is used to do more than that. ^ C. No, this choice is totally incorrect.

^ D. You are correct. @ A 45 degrees shear angle beam transducer produces a wave in the metal which is polarized: \d | A. Perpendicular to the direction of propagation and parallel to the entry surface. | B. In the direction of propagation and at 45 degrees to the normal to the entry surface. | C. Perpendicular to the entry surface. | D. Perpendicular to the direction of propagation and at 45 degree to the entry surface. ^ A. No, it is not parallel to the entry surface. ^ B. Sorry! Please try again. ^ C. No, polarization direction is related primarily to the direction of the propagation. ^ D. You are correct. @ In straight (normal) beam contact testing, a reduction in the back surface reflection amplitude could indicate: \d | A. Inadequate coupling. | B. A flaw which is not normal to the beam. | C. A near surface defect that cannot be resolved from the main bang (initial pulse). | D. All of the above

^ A. Yes, but there could be several other reasons too. ^ B. Yes, but there could be several other reasons too. ^ C. Yes, but there could also be several other reasons. ^ D. You are absolutely correct. @ In an automatic scanning immersion unit, the bridge or carriage serves to: \a | 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 tube. | C. Control the vertical and angular positioning of the scanner tube. | D. Raise and lower the transducer. ^ A. Absolutely correct. ^ B. No, bridge or carriage cannot be used to angulate. ^ C. No, bridge or carriage cannot be used to angulate. ^ D. No, bridge and carriage cannot be used to raise and lower the transducers. @ When adjusting the flaw locating rule for a shear wave weld inspection, the zero point on the rule must coincide with the: \a | A. Sound beam exit point of the wedge | B. Point directly over the flaw

| C. Wheel search unit | D. Circular scanner ^ A. Outstanding ^ B. Sorry! This choice is irrelevant. ^ C. Sorry! Please try again. ^ D. Sorry! This choice is irrelevant. @ A special scanning device with the transducer mounted in a tire- like container filled with couplant is commonly called; \c | A. A rotating scanner | B. An axial scanner | C. A wheel search unit | D. A circular scanner ^ A. No, but you are on the right track. ^ B. No, it rotates. ^ C. You are correct. ^ D. Sorry! Please try again. @ Which best describes a typical display of a crack whose major surface is perpendicular to the ultrasonic beam? \b | 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. No, since the beam is perpendicular to the crack, indication is not broadened. ^ B. You are absolutely correct. ^ C. No, it will definitely show because of most favorable orientation. ^ D. No, since the beam is perpendicular to the crack, indication is not broadened. @ Compensation for the variation in echo height related to variations in discontinuity depth in the test material is known as: \c | A. Transfer | B. Attenuation | C. Distance amplitude correction | D. Interpretation ^ A. Sorry! Your choice is incorrect. ^ B. No, attenuation causes change in the amplitude as the sound propagates. ^ C. Absolutely correct. ^ D. Sorry! Your choice is incorrect. @ Which of the following is a reference reflector that is not dependent on beam angle \c | A. A flat bottomed hole | B. A vee notch

| C. A side drilled hole which is parallel to the plate surface and perpendicular to the sound path | D. A disc shaped laminar reflector ^ A. No, it certainly depends on beam angle. It is useful only for a zero degree angle. ^ B. No, it certainly depends on beam angle. It is useful for angle beam testing. ^ C. You got it ^ D. No, it certainly depends on beam angle. It is useful only for a zero degree angle. @ During a straight beam ultrasonic test a discontinuity indication is detected which is small in amplitude compared to the loss in amplitude of back reflection. The orientation of this discontinuity is probably: \d | A. Parallel to the test surface. | B. Parallel (plus or minus 5 degrees) from the test surface. | C. Parallel to the sound beam. | D. Such that complete loss of back reflection will result. ^ A. No, if it was parallel, it should have given a large indication. ^ B. Sorry! Please try again. ^ C. No, if it were parallel to the sound beam, loss of back surface reflection should be very small.

^ D. You are correct. @ 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: \b | 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. No, large indications would be obtained if it were perpendicular ^ B. Outstanding ^ C. No, apply the golden rule of ultrasonics. ^ D. No, you are not on the right track. @ Gas discontinuities are reduced to flat discs or other shapes parallel to the surface by: \a | A. Rolling | B. Machining | C. Casting | D. Welding ^ A. You are correct. ^ B. No, machining can't make them flat or parallel to the surface.

^ C. No, casting typically produces bubbles which are spherical. ^ D. No, welding typically produces bubbles which are spherical. @ In which zone does the amplitude of an indication from a given discontinuity diminish exponentially as the distance increases? \a | A. Far field zone | B. Near field zone | C. Dead zone | D. Fresnel zone ^ A. You are correct. ^ B. No, in near field amplitude changes rapidly. ^ C. No, you can not find the defect in this zone, so question of amplitude change is irrelevant. ^ D. No, in the fresnel zone, amplitude changes rapidly. @ A smooth flat discontinuity whose major plane is not perpendicular to the direction of sound propagation may be indicated by: \d | A. An echo amplitude comparable in magnitude to the back surface reflection. | B. A complete loss of the back surface reflection. | C. An echo amplitude larger in magnitude than the back surface reflection.

| D. All of the above. ^ A. Yes, but there are other possibilities. ^ B. Yes, but there are other possibilities. ^ C. Yes, but there are other possibilities. ^ D. You are correct. @ 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: \b | 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. No, signal linearity is not related to angle. ^ B. You are absolutely correct. ^ C. No, this answer is wrong. Curved discontinuity can cause focussing, but not plane discontinuity. ^ D. No, this answer is wrong. @ As transducer diameter decreases, the beam spread: \c | A. Decreases | B. Remains the same | C. Increases | D. Becomes conical in shape

^ A. No, beam spread is a function of wavelength / transducer diameter. ^ B. No, beam spread is a function of wavelength / transducer diameter. ^ C. You are correct. ^ D. Sorry! Please try again. @ A set of standard reference blocks with the same geometrical configuration and dimensions other than the size of the calibration reflectors, e.g., flat bottom holes, is called a set of: \b | A. Distance/amplitude standards. | B. Area/amplitude standards. | C. Variable frequency blocks. | D. Beam spread measuring blocks. ^ A. No, in this type size of reflector remains constant. ^ B. You are correct. ^ C. Sorry! Such a thing does not exist in UT. ^ D. Sorry! Please try again. @ The angle at which 90 degree refraction of a longitudinal sound wave is reached is called: \b | A. The angle of incidence. | B. The first critical angle. | C. The angle of maximum reflection.

| D. The second critical angle. ^ A. No, angle of incidence can be any angle from 0 to 90 degrees. ^ B. You are right. ^ C. No. Think harder. ^ D. No, at second critical angle, shear waves reach 90 degree angle of refraction. @ Which of the following controls the voltage supplied to the vertical deflection plates of the CRT in an A-scan UT setup? \c | A. Sweep generator | B. Pulser | C. Amplifier circuit | D. Clock timer ^ A. No, sweep generator controls horizontal deflection plates. ^ B. No, pulser excites the transducer. ^ C. You are right. ^ D. Sorry! Try again. @ 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 which can include: \d | A. Beam spread

| B. Couplant mismatch | C. Test piece geometry | D. All of the above ^ A. True, but there are other mechanisms also. ^ B. True, but there are other mechanisms also. ^ C. True, but there are other mechanisms also. ^ D. You are exactly right. @ The vertical linear range of a test instrument may be determined by obtaining ultrasonic responses from: \c | A. A set of distance-amplitude reference blocks. | B. Steel balls located at several different water path distances. | C. A set of area-amplitude reference blocks. | D. All of the above. ^ A. No, distance should be kept constant. ^ B. No, distance should be kept constant. ^ C. You are correct. ^ D. No, not all are true. @ Large grains in a metallic test specimen usually result in: \d | A. Decrease or loss of back surface reflection. | B. Large "hash" or noise indications. | C. Decrease in penetration.

| D. All of the above. ^ A. You are partially correct. ^ B. You are partially correct. ^ C. You are partially correct. ^ D. You are absolutely correct. @ The total energy losses occurring in all materials is called: \a | A. Attenuation | B. Scatter | C. Beam spread | D. Interface ^ A. Outstanding ^ B. No, this is one of the reasons which causes energy loss. ^ C. No, this is one of the reasons which causes energy loss. ^ D. No, this is one of the reasons which causes energy loss. @ Delay-tip(stand-off)type contact search units are primarily used for: \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. 173.

@ 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. 174.

@ The attenuation of energy within a material in the far field

of the ultrasonic beam may be expressed as the: \d | 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. @ For aluminum and steel the longitudinal velocity is approximately _________ the shear velocity: \b | A. Equal to | B. Twice | C. One-half of | D. Four times ^ A. Incorrect, shear wave velocity is much smaller than longitudinal wave velocity. ^ B. You are absolutely correct.

^ C. Incorrect, shear wave travel slower than longitudinal waves. ^ D. Incorrect. You are close. @ Water travel distance for immersion inspections should be: \a | A. Such that the second front reflection does not appear between the first front and back reflections. | B. Exactly 3 inches. | C. Less than 3 inches. | D. Always equal to the thickness of the material being inspected. ^ 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. 175.

@ 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 | A. An electronic gate. | B. An electronic attenuator. | C. A distance amplitude correction circuit. | D. A fixed marker. ^ A. Outstanding

^ B. No. Attenuator attenuates the signal and does not do selection. ^ C. Sorry! Please try again. ^ D. Sorry! DAC is applied throughout the thickness of material. @ When conducting a contact ultrasonic test, the "hash" or irregular signals that appear in the CRT display of the area being inspected could be caused by: \c | 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. No, hash is directly proportional to grain size. ^ B. No, in contact testing, dirt in water couplant is not a major problem. ^ C. You are correct. ^ D. No. This will reduce back surface reflection. Hash is related to grain structure. @ In inspecting a 4-inch diameter threaded steel cylinder for radial cracks extending from the root of the threads, it would be preferable to transmit: \b | 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. No, You will get too many reflections from threads. ^ B. You are correct. ^ C. Incorrect. How do you launch surface waves perpendicular to the direction of thread roots ^ D. Incorrect. How do you launch shear waves around the circumference of the cylinder @ In an immersion inspection of raw material, the water travel distance should be: \c | A. Exactly 3 inches. | B. Equal to 3 inches (plus or minus 1/2 inch). | C. Equal to the water travel distance used in setting up on the reference standards. | D. Equal to the thickness of a material. ^ A. Incorrect. Water traveling distance depends on material thickness and wave velocity. ^ B. Incorrect. Water traveling distance depends on material thickness and wave velocity. ^ C. You are correct. ^ D. No, this can cause a confusing screen presentation.

@ 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: \b | A. The angle of incidence. | B. The angle of refraction. | C. The angle of rarefaction. | D. The angle of reflection. ^ A. No, Angle of incidence is in the host medium. ^ B. You've got it. ^ C. No, there is no such angle. ^ D. No, angle of reflection is in the same host medium as the angle of incidence. @ The process of adjusting an instrument or device to a reference standard is referred to as: \d | A. Angulation | B. Scanning | C. Correcting for distance-amplitude variations | D. Calibration ^ A. No, angulation is done in immersion testing to get peak amplitude signal. ^ B. Sorry! Scanning involves moving transducer back and forth over a sample, usually in immersion mode.

^ C. Sorry! Your choice is incorrect. ^ D. You're right. @ An electron tube in which a beam of electrons from the cathode is used to reproduce an image on a fluorescent screen at the end of the tube is referred to as: \c | A. An amplifier tube | B. A pulser tube | C. A cathode ray tube | D. A sweep tube ^ A. Incorrect. There is no such thing in UT. ^ B. Incorrect. There is no such thing in UT. ^ C. You are correct. ^ D. Incorrect. There is no such thing in UT. @ A grouping of a number of crystals in one search unit, with all contact surfaces in the sample plane, and vibrating in phase with each other to act as a single transducer is called a: \b | A. Focusing crystal | B. Crystal mosaic | C. Scrubber | D. Single plane manipulator ^ A. Sorry! Please try again. ^ B. Excellent

^ C. Sorry! Please try again. ^ D. Sorry! Please try again. @ The scattering of the ultrasonic energy of an ultrasonic beam due to reflection from a highly polished surface is called: \b | A. Angulation | B. Dispersion | C. Refraction | D. Rarefaction ^ A. Sorry! Please try again. ^ B. You are absolutely correct. ^ C. No, refraction occurs when two medias are involved. ^ D. No, rarefaction is associated with the way longitudinal wave propagates. @ The angle of reflection is: \a | 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. You are correct. ^ B. No, apply Snell's law. ^ C. No, apply Snell's law. ^ D. No, apply Snell's law.

@ The angular position of the reflecting surface of a planar discontinuity with respect to the entry surface is referred to as: \c | A. The angle of incidence. | B. The angle of refraction. | C. The orientation of the discontinuity. | D. None of the above. ^ A. No, angle of incidence is associated with the wave. ^ B. No, angle of incidence is associated with the wave. ^ C. You are right. ^ D. Sorry! Your choice is incorrect. @ A short burst of alternating electrical energy is called: \d | A. A continuous wave | B. A peaked DC voltage | C. An ultrasonic wave | D. A pulse ^ A. No, continuous wave is not short. ^ B. No, look at the key word "alternating" ^ C. Incorrect. Ultrasonic wave is not electric energy. ^ D. Super! You are absolutely correct. @ In ultrasonic testing, the time duration of the transmitted pulse is referred to as: \a

| A. The pulse length or pulse width | B. The pulse amplitude | C. The pulse shape | 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. @ The phenomenon by which a wave strikes a boundary and changes the direction of its propagation within the same medium is referred to as: \d | A. Divergence | B. Impedance | C. Angulation | D. Reflection ^ A. No, divergence is a function of wavelength/transducer diameter ^ 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 passes from one medium to another whose velocity differs from that of

the first medium is called: \a | A. Refraction | B. Rarefaction | C. Angulation | D. Reflection ^ A. You've got it. ^ B. No, rarefaction is associated with the way longitudinal wave propagates. ^ C. Sorry! This answer is incorrect. ^ D. No, reflection occurs within the same medium. @ The coated inside surface of the large end of a cathode ray tube which becomes luminous when struck by an electron beam is called: \c | A. An electron gun | B. An electron amplifier | C. A CRT screen | D. An electron counter ^ 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." 176. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

177. ULTRASONICS TESTING LEVEL II 178. @ 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! 179.

@ 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. 180.

@ 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. 181.

@ 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. 182.

@ In an ultrasonic instrument, the number of pulses produced by

an instrument in a given period of time is known as the: \d |A. Pulse length of the instrument. |B. Pulse recovery time. |C. Frequency. |D. Pulse repetition rate. ^A. No. Look at the units. ^B. No. Look at the units. ^C. Sorry! Frequency is related to the transducer. ^D. You are correct. 183.

@ In a basic pulse-echo ultrasonic instrument, the component

that coordinates the action and timing of other components is called a: \d |A. Display unit or CRT. |B. Receiver. |C. Marker circuit or range marker circuit. |D. Synchronizer, clock, or timer. ^A. Sorry! Information is displayed on CRT.

^B. Sorry! Receiver amplifies a signal. ^C. Sorry! Try again. ^D. Excellent! 184.

@ In a basic pulse-echo ultrasonic instrument, the component that

produces the voltage that activates the search unit is called: \c |A. An amplifier |B. A receiver |C. Pulser |D. A synchronizer ^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. 185.

@ In a basic-pulse-echo ultrasonic instrument, the voltage

producing component which activates the search unit is called: \a |A. Sweep circuit |B. Receiver |C. Pulser |D. Synchronizer ^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. 186.

@ In a basic pulse-echo ultrasonic instrument, the component

that produces visible signals on the CRT which are used to measure distance is called a: \b |A. Sweep circuit |B. Marker circuit |C. Receiver circuit |D. Synchronizer ^A. Sorry! Try again. ^B. You've got it. ^C. Sorry! Receiver amplifies the signal. ^D. Sorry! The synchronizer coordinates action and timing. 187.

@ 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. 188.

@ The cathode ray tube screen will display a plan view of the part

outline and defects when using: \d |A. Automatic read-out equipment. |B. An A-scan presentation. |C. A B-scan presentation. |D. A C-scan presentation. ^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. 189.

@ The incident angles at which 90 degrees refraction of

longitudinal and shear waves occurs are called: \b |A. The normal angles of incidence. |B. The critical angles. |C. The angles of maximum reflection. |D. None of the above. ^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.

190.

@ Compression waves whose particle displacement is parallel to

the direction of propagation are called: \a |A. Longitudinal waves |B. Shear waves |C. Lamb waves |D. Rayleigh waves ^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. 191.

@ Which of the following modes of vibration are quickly damped

out when testing by the immersion method? \d |A. Longitudinal waves |B. Shear waves |C. Transverse waves |D. Surface waves ^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. 192.

@ The motion of particles in a shear wave is:

\b |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 degrees to the direction of beam propagation. ^A. No, this defines the longitudinal waves. ^B. You are correct. ^C. No, this defines the surface waves. ^D. Sorry! Please try again. 193.

@ In contact testing, shear waves can be induced in the test

material by: \d |A. Placing a 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. 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. 194.

@ As frequency increases in ultrasonic testing, the angle of

beam divergence of a given diameter crystal: \a |A. Decreases. |B. Remains unchanged. |C. Increases. |D. Varies uniformly through each wavelength. ^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. 195.

@ Which of the following is not an advantage of contact

ultrasonic search units(probes) adapted with lucite shoes? \c |A. Eliminates most of the crystal wear. |B. Permits adaptation to curved surfaces. |C. Decreases sensitivity. |D. Allows ultrasound to enter a part's 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. 196.

@ In which medium listed below would the velocity of sound be

lowest? \a |A. Air |B. Water |C. Aluminum |D. Stainless steel ^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. 197.

@ A longitudinal ultrasonic wave is transmitted from water into

steel at an angle of 5 degrees from the normal. In such a case the refracted angle of the transverse wave is: \a |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. You are right on target. ^B. No, apply Snell's law. ^C. No, think about Snell's law. ^D. No, you are incorrect. 198.

@ 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. 199.

@ In steel, the velocity of sound is greatest in which of the

following modes of vibration? \a | A. Longitudinal | B. Shear | C. Surface waves. | D. Sound velocity is identical in all modes, in a given material.

^ 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. 200.

@ The acoustic impedance is:

\b | 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. Sorry! Acoustic impedance is used for calculating transmission and reflection of ultrasound. ^ B. You are right on target. ^ C. Sorry! Acoustic impedance is used for calculating transmission and reflection of ultrasound. ^ D. Sorry! Acoustic impedance is used for calculating transmission and reflection of ultrasound. 201.

@ Thin sheet may be inspected with the ultrasonic wave directed

normal to the surface by observing: \b | A. The amplitude of the front surface reflection. | B. The multiple reflection pattern.

| C. All front surface reflections | D. None of the above. ^ A. No, front surface signal will have a considerable dead zone. ^ B. Outstanding ^ C. Sorry! Try again. ^ D. No, there is a correct answer. 202.

@ 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: \c | A. Schematic diagram | B. Blueprint | C. Block diagram | D. None of the above ^ 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. 203.

@ A hole produced during the solidification of metal due to

escaping gases is called: \d | A. A burst | B. A cold shut

| C. A flaking | D. A blow hole ^ A. Sorry! You've answered incorrectly. ^ B. Sorry! A cold shut is caused by splashing, singing, interrupted pouring etc. ^ C. Sorry! You've answered incorrectly. ^ D. You are right.

@ 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: \b | A. A burst | B. A cold shut. | C. Flaking | D. A blow hole ^ A. Sorry! You've answered incorrectly. ^ B. Great ^ C. Sorry! Your answer is wrong. ^ D. No, blow holes are produced by escaping gases. 204.

@ The ratio between the wave speed in one material and the wave

speed in a second material is called: \d

| A. The acoustic impedance of the interface | B. Young's modulus | C. Poisson's ratio | D. The index of refraction. ^ A. Sorry, your answer is incorrect. ^ B. Sorry! Young's modulus is a ratio of stress and strain. ^ C. No, Poisson's ratio is a ratio of strains. ^ D. You got it. 205.

@ The expansion and contraction of a magnetic material under the

influence of a changing magnetic field is referred to as: \c | A. Piezoelectricity | B. Refraction. | C. Magnetostriction | D. Rarefaction ^ A. Piezoelectricity is due to pressure or stress. ^ B. No, refraction is associated with transmission of sound waves through a layered media. ^ C. You are correct. ^ D. No, rarefaction is associated with the way longitudinalwave propagates through a material. 206.

@ The ratio of stress to strain in a material within the elastic

limit is called: \c

| A. Young's modulus | B. The Modulus of elasticity | C. Both A and B | D. The index of refraction ^ A. Yes, but another choice is also correct. ^ B. Yes, but another choice is also correct. ^ C. You are right on target. ^ D. Sorry! Index of refraction is ratio of wave speeds in two adjacent materials. 207.

@ A point, line, or surface of a vibrating body marked by absolute

or relative freedom from vibratory motion is referred to as: \a | A. A node | B. An antinode | C. Rarefaction | D. Compression ^ A. You are absolutely right. ^ B. Sorry! Amplitude of vibratory motion is largest in antinodes. ^ C. Sorry! A longitudinal wave propagates by means of "compression and rarefaction of material particles. ^ D. Sorry! A longitudinal wave propagates by means of "compression and rarefaction of material particles. 208.

@ 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: \b | A. A Y-cut crystal | B. A X-cut crystal | C. A Z-cut crystal | D. A ZY-cut crystal ^ A. No, this type of cut generates L-waves. ^ B. You are correct. ^ C. Sorry! Your answer is incorrect. ^ D. Sorry! Your answer is incorrect. 209.

@ The equation describing wavelength in terms of velocity and

frequency is: \c | A. Wavelength = Velocity x Frequency | B. Wavelength = Z (Frequency x Velocity | C. Wavelength = Velocity / Frequency | D. Wavelength=Frequency + Velocity ^ A. No. Check units to find the correct relationship. ^ B. No. Check units to find the correct relationship. ^ C. Yes, you got it. ^ D. No. Check units to find the correct relationship. 210.

@ Which of the following can occur when an ultrasonic beam

reaches the interface of two dissimilar materials? \d

| A. Reflection | B. Refraction | C. Mode conversion | D. All of the above ^ 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 211.

@ Of the piezoelectric materials listed below, the most

efficient sound transmitter is: \c | A. Lithium sulfate | B. Quartz | C. Barium titanate | D. Silver oxide ^ A. No, this is the best receiver. ^ B. Sorry! Try again. ^ C. You got it. ^ D. Incorrect, silver oxide is not a piezoelectric material. 212.

@ Of the piezoelectric materials listed below, the most

efficient sound receiver is: \a | A. Lithium sulfate | B. Quartz

| C. Barium titanate | D. Silver oxide. ^ 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. 213.

@ The most commonly used method of producing shear waves in a

test part when inspecting by the immersion method is: \d | A. By transmitting longitudinal waves into a part in a direction 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. ^ 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. 214.

@ Beam divergence is a function of the dimensions of the crystal

and the wavelength of the beam transmitted through a medium, and it: \a | A. increases if the frequency or crystal diameter is decreased. | B. decreases if the frequency or crystal diameter is

decreased. | C. increases if the frequency is increased and crystal diameter decreased. | D. decreases if the frequency is increased and crystal diameter is decreased. ^ 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). 215. @ The wavelength of an ultrasonic wave is: \b | 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 the velocity and frequency. ^ 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. 216.

@ The fundamental frequency of a piezoelectric crystal is

primarily a function of:

\c | A. the length of the applied voltage pulse. | B. the amplifying characteristics of the pulse amplifier in the instrument. | C. the thickness of the crystal. | D. none of the above. ^ A. No, it is related to a transducer dimension. ^ B. No, it is related to a transducer dimension. ^ C. You are correct. ^ D. No, there is a correct answer. 217.

@ Acoustic velocities are primarily described by:

\c | A. density | B. elasticity | C. both A and B | D. acoustic impedance ^ A. Yes, but there is another factor. ^ B. Yes, but there is another factor. ^ C. Outstanding ^ D. Sorry! Acoustic impedance determines transmission and reflection of sound. 218.

@ Inspection of castings is often impractical because of:

\b | A. extremely small grain structure.

| B. coarse grain structure. | C. uniform flow lines. | D. uniform velocity of sound. ^ A. Incorrect, it is easy to inspect small grain structure materials ^ B. You are absolutely right. ^ C. Sorry! Attenuation determines inspectability. ^ D. Sorry, your answer is incorrect. 219.

@ Lamb waves may be used to inspect:

\d | A. forgings | B. bar stock | C. ingots | D. thin sheet ^ A. No, Lamb waves do not travel in thick material. ^ B. No, Lamb waves do not travel in thick material. ^ C. No, Lamb waves do not travel in thick material. ^ D. You are correct. 220.

@ The resolving power of a search unit is directly proportional

to its: \b | A. diameter | B. band width | C. pulse repetition

| D. none of the above ^ A. Sorry! Diameter does not directly influence resolution. ^ B. Great ^ C. No, resolution is dependent on pulse duration and frequencies. ^ D. Sorry! There is a correct answer. 221.

@ In the basic pulse-echo instrument, the synchronizer, clock or

timer circuit will determine the instrument's: \c | A. pulse length | B. gain | C. pulse repetition rate | D. sweep length ^ A. No, transducer and excitation pulse determine pulse length. ^ B. No, excitation pulse voltage determines gain. ^ C. You got it. ^ D. Sorry! Your answer is incorrect. 222.

@ The primary requirement of a paintbrush transducer is that:

\b | 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 .01%. | D. the overall length not exceed 3 inches. ^ A. No, paintbrush transducer has only one crystal. ^ B. Outstanding ^ C. No, paintbrush transducer has only one crystal. ^ D. Sorry! Your answer is incorrect. 223.

@ Heat conduction, viscous friction, elastic hysteresis, and

scattering are four different mechanisms which lead to: \a | A. attenuation | B. refraction | C. beam spreading | D. saturation. ^ A. You got it. ^ B. No, sound propagation at an angle through different media causes refraction. ^ C. Sorry! Beam spread is a function of wavelength and transducer diameter. ^ D. Sorry! This choice is incorrect. 224.

@ Since the velocity of sound in aluminum is approximately 245,000

in/sec, how long does it take for sound to travel through 1 inch of aluminum? \b | A. 1/8 second

| B. 4 microseconds | C. 4 milliseconds | D. 1/4 X 100000 seconds ^ A. No, divide distance by speed. ^ B. You are right on the mark. ^ C. No, check your math. ^ D. No, divide distance by speed. 225.

@ When testing a part with a rough surface, it is generally

advisable to use: \a | A. a lower frequency search unit and a more viscous couplant than is used on parts with a smooth surface. | B. a higher frequency search unit and a more viscous couplant than is used on parts with a smooth surface. | C. a higher frequency search unit and a less viscous couplant than is used on parts with a smooth surface. | D. a lower frequency search unit and a less viscous couplant than is used on parts with a smooth surface. ^ A. You are correct. ^ B. No, it will cause too much scattering. ^ C. No, the air bubbles may cause problems. ^ D. No, air bubbles may cause problems. 226.

@ Reflection indications from a weld area being inspected by the

angle-beam technique may represent:

\d | A. Porosity | B. Cracks | C. Weld bead | D. All three of the above ^ A. No, there are several other reflector types which can also give indications. ^ B. No, there are several other reflector types which can also give indications. ^ C. No, there are several other reflector types which can also give indications. ^ D. You are correct. @ In an A-scan presentation, the horizontal line formed by the uniform and repeated movement of an electron beam across the fluorescent screen of a cathode ray tube is called: \b | A. A square wave pattern. | B. A sweep line. | C. A marker pattern. | D. None of the above. ^ A. Sorry! This choice is incorrect. ^ B. Excellent! You are exactly right. ^ C. Sorry! This choice is incorrect. ^ D. No, there is a correct answer.

@ Which of the following frequencies would probably result in the greatest amount of attenuation losses? \d | A. 1.0 megahertz. | B. 2.25 megahertz. | C. 5 megahertz. | D. 10 megahertz. ^ A. No, attenuation losses are directly proportional to frequency. ^ B. No, attenuation losses are directly proportional to frequency. ^ C. No, attenuation losses are directly proportional to frequency. ^ D. Super @ In general, which waves will travel around gradual curves with little or no reflection from the curve? \b | A. Transverse waves. | B. Surface waves. | C. Shear waves. | D. Longitudinal waves. ^ 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. 227.

@ To evaluate and accurately locate discontinuities after

scanning a part with a paintbrush transducer, it is generally necessary to use a: \a | A. Search unit with a smaller crystal. | B. Scrubber. | C. Grid map. | D. Crystal collimator. ^ 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 @ When using two separate search units (one a transmitter, the other a receiver), the most efficient combination would be: \b | A. A quartz transmitter and a barium titanate receiver. | B. A barium titanate transmitter and a lithium sulfate receiver. | C. A lithium sulfate transmitter and a barium titanate receiver. | D. A barium titanate transmitter and a quartz receiver. ^ 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. 228.

@ In immersion testing, the accessory equipment to which the

search cable and the search unit are attached is called a: \d | A. Crystal collimator. | B. Scrubber. | C. Jet-stream unit. | D. Search tube or scanning tube. ^ A. Sorry! This choice is incorrect. ^ B. Sorry! This choice is incorrect. ^ C. Sorry! This choice is incorrect. ^ D. You are correct. @ In general, discontinuities in wrought products tend to be oriented: \b | 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. No, the key words are "wrought products." ^ B. Super ^ C. No. The key words are "wrought products."

^ D. No. The key words are "wrought products." @ In immersion testing irrelevant or false indications caused by contoured surfaces are likely to result in a: \a | A. Broad-based indication. | B. Peaked indication. | C. "Hashy" signal. | D. Narrow-based indication. ^ A. You are correct. ^ B. Sorry! Curved surface tends to increase pulse duration. ^ C. No, "hashy" signal is caused by electronic or material noise. ^ D. No, curved surface tends to increase pulse duration. @ In contact testing, defects near the entry surface cannot always be detected because of: \c | A. The far-field effect. | B. Attenuation. | C. The dead zone. | D. Refraction. ^ A. No, the far-field effect does not come into play near the entry surface in contact testing. ^ B. Sorry! Attenuation near the entry surface should not be a major factor.

^ C. You are correct. ^ D. Sorry, this answer is incorrect. @ 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? \b | A. A scrubber. | 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 229.

| A. One inch.

| B. Four inches. | C. One wavelength. | D. Four wavelengths. ^ A. No, the surface waves do not penetrate much into the material. ^ B. No, the surface waves do not penetrate much into the material. ^ C. Excellent!! You are correct. ^ D. No, the surface waves do not penetrate much below one wavelength. @ 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 one inch of water for every: \b | A. Two inches of aluminum. | B. Four inches of aluminum.

| C. Six inches of aluminum. | D. Eight inches of aluminum. ^ A. No, the water path should be at least four times smaller than the test specimen. ^ B. You are correct. ^ C. No, the water path should be at least four times smaller than the test specimen. ^ D. No, the water path should be at least four times smaller than the test specimen. @ Increasing the length of the pulse used to activate the search unit will: \a | A. Increase the strength of the ultrasound but decrease the resolving power ofthe 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. You are correct. ^ B. No, the pulse length is increased, therefore resolving power is decreased. ^ C. No, the pulse length is increased, therefore resolving power is decreased. ^ D. No, the penetration is increased. @ Of the following sound wave modes, which one has multiple or

varying wave velocities? \d | A. Longitudinal waves | B. Shear waves | C. Transverse waves | D. Lamb waves ^ A. No, longitudinal waves have one velocity in any given material. ^ B. No, shear waves have one velocity in any given material. ^ C. No, transverse waves have one velocity in any given material. ^ D. You are correct. @ Which of the following would be considered application(s) of ultrasonic techniques? \d | A. Determination of a material's elastic modulus | B. Study of a material's metallurgical structure | C. Measurement of a material's thickness | D. All of the above. ^ A. True, but you can do much more with ultrasonics. ^ B. True, but you can do much more with ultrasonics. ^ C. True, but you can do much more with ultrasonics. ^ D. Very good. You are absolutely correct. @ The only significant sound wave mode that will travel through

a liquid is: \b | A. Shear | B. Longitudinal | C. Surface | D. Rayleigh ^ A. No, liquids do not support shear waves. ^ B. You are correct. ^ C. No, Liquids do not support surface waves. ^ D. No, liquids do not support Rayleigh waves. @ The acoustic impedance of a material is used to: \c | A. Determine the angle of refraction at an interface. | B. Determine the attenuation within the material. | C. Find the amounts of sound energy reflected and refracted through an interface. | D. Determine the beam spread within the material. ^ A. No, velocity ratio is used for determining angle of refraction. ^ B. Sorry! Frequency, wavelength, grain size, etc. are used to calculate attenuation. ^ C. You are correct. ^ D. No, wavelength and transducer diameter are needed to calculate beam spread.

@ Acoustic energy propagates in different modes. Which of the following represents a mode? \d | A. Longitudinal wave | B. Shear wave | C. Surface wave | D. All of the above ^ A. Sorry! There are several other modes as well. ^ B. Sorry! There are several other modes as well. ^ C. Sorry! There are several other modes as well. ^ D. You are absolutely correct. @ When angle beam contact testing a test piece, increasing the incident angle until the second critical angle is reached results in: \c | A. Total reflection of a surface wave. | B. 45 degree refraction of the shear wave | C. Production of a surface wave | D. None of the above ^ A. No. What does total reflection mean ^ B. No. Try to apply Snell's law. ^ C. You are correct. ^ D. No. Try to apply Snell's law. @ The simple experiment where a stick in a glass of water appears disjointed at the water surface illustrates the phenomenon of:

\c | A. Reflection | B. Magnification | C. Refraction | D. Diffraction ^ A. No, reflection should not make it appear disjointed. ^ B. No, magnification means to enlarge - It means different from disjointed. ^ C. You are correct. ^ D. Sorry! you've answered incorrectly. @ The crystal thickness and transducer frequency are related. The thinner the crystal: \b | A. The lower the frequency | B. The higher the frequency | C. There is no appreciable effect | D. None of the above ^ A. No, there is an inverse relationship. ^ B. You are correct. ^ C. No, there is an inverse relationship. ^ D. No, there is an inverse relationship. @ The random distribution of crystallographic direction in alloys with large crystalline structure is a factor in determining: \d

| A. Acoustic noise levels | B. Selection of test frequency | C. Scattering of sound | D. All of the above ^ A. True, but there are other considerations as well. ^ B. True, but there are other considerations as well. ^ C. True, but there are other considerations as well. ^ D. You are correct. @ The length of the zone adjacent to a transducer in which fluctuations in sound pressure occur is mostly affected by: \d | A. The frequency of the transducer | B. The diameter of the transducer | C. Scattering of sound | D. Both A and B ^ A. True, but there is another factor too. ^ B. True, but there is another factor too. ^ C. No, scattering of sound is irrelevant here. ^ D. You are correct. @ The differences in signals received from identical reflectors at different material distances from a transducer may be caused by: \d | A. Material attenuation. | B. Beam divergence.

| C. Near field effects. | D. All of the above. ^ A. True, but there are other reasons too. ^ B. True, but there are other reasons too. ^ C. True, but there are other reasons too. ^ D. Excellent! You are right. @ It is possible for a discontinuity smaller than the transducer to produce indications of fluctuating amplitude as the search unit is moved laterally if testing is being performed in the: \b | A. Fraunhofer zone. | B. Near field. | C. Snell field. | D. Shadow zone. ^ A. No, signal should remain constant. ^ B. You've got it. ^ C. Sorry! No such thing in UT. ^ D. Sorry, your answer is incorrect. @ In immersion testing, the near field effects of a transducer may be eliminated by: \c | A. Increasing transducer frequency. | B. Use of larger diameter transducer. | C. Using an appropriate water path.

| D. Use of a focused transducer. ^ A. No, nearfield distance is increased. ^ B. No, nearfield distance is increased. ^ C. You've got it ^ D. Sorry! This choice is incorrect. @ 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? \c | A. Multiple indications before the first back reflection. | B. Indications from multiple surface reflection. | C. Conversion from the longitudinal mode to shear mode. | D. Loss of front surface indications. ^ A. Not true if the rod is smooth, i.e. no scratches, cracks, etc. ^ B. No. This is not possible. ^ C. Absolutely ^ D. No, this is not possible. @ Where does beam divergence occur? \b | A. Near field. | B. Far field. | C. At the crystal. | D. None of the above.

^ A. No, not in the nearfield. ^ B. That's correct. ^ C. No, it is not at the crystal but away from it. ^ D. No, beam diverges after the Fresnel zone. @ As frequency increases in ultrasonic testing, the angle of beam divergence of a given diameter crystal: \a | A. Decreases | B. Remains unchanged | C. Increases | D. Varies uniformly through each wavelength ^ A. Super! You are correct. ^ B. No, angle of divergence is a function of wavelength/transducer diameter. ^ C. No, angle of divergence is a function of wavelength/transducer diameter. ^ D. No, angle of divergence is a function of wavelength/transducer diameter. @ As the radius of curvature of a curved lens is increased, the focal length of the lens will: \a | A. Increase | B. Decrease | C. Remain the same

| D. Be indeterminate unless the frequency is known ^ A. You've got it. ^ B. No, flat surface has infinite radius of curvature. ^ C. No, it will definitely increase or decrease. ^ D. No, it will definitely increase or decrease. @ When examining materials for planar flaws oriented parallel to the part surface, what testing method is most often used? \c | A. Angle beam | B. Through-transmission | C. Straight beam | D. Dual crystal ^ A. No, angle beam testing is most useful when flaw is oriented perpendicular to the part surface. ^ B. No, through-transmission is most useful in highly attenuative materials. ^ C. You've got it. ^ D. No, dual crystal transducer are used when flaw is located close to the surface. @ Rayleigh waves are influenced most by defects located: \c | A. One wavelength below the surface | B. Six wavelengths below the surface | C. Close to or on the surface

| D. Three wavelengths below the surface ^ 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. 230.

@ The ratio of the velocity of sound in water compared to that

for aluminum or steel is approximately: \a | A. 1:4 | B. 1:2 | C. 1:8 | D. 1:3 ^ A. You are correct. ^ B. Sorry! This choice is incorrect. ^ C. Sorry! Please try again. ^ D. Sorry! Your answer is incorrect. @ Which of the following scanning methods could be classified as an immersion type test? \d | A. Tank in which the search unit and test piece are immersed | B. Squirter bubbler method in which the sound is transmitted

in a column of flowing water | C. Scanning with a wheel-type search unit with the transducer inside a liquid filled tire | D. All of the above ^ A. True, but there are other set ups as well. ^ B. True, but there are other set ups as well. ^ C. True, but there are other set ups as well. ^ D. That is correct. @ 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 | A. Reduced velocity of sound in water as compared to test specimen. | B. Increased velocity of sound in water as compared to test specimen. | C. Temperature of the water. | D. All of the above. ^ A. Super! You are correct. ^ B. No, velocity of sound in water is lower than test specimen. ^ C. No, velocity of sound in water is lower than test specimen. ^ D. No, velocity of sound in water is lower than test specimen. @ What law can be used to calculate the angle of refraction

within a metal for both longitudinal and shear waves? \b | A. Poisson's Ratio Law | B. Snell's Law | C. Fresnel's Field Law | D. Charles' Law ^ A. Sorry! Please try again. ^ B. You've got it. ^ C. Sorry! Your choice is incorrect. ^ D. Sorry! This choice is incorrect. @ At an interface between two different materials, an impedance difference results in: \c | 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. None of the above ^ A. No, some of it goes into the second material and some is reflected. ^ B. No, it is both transmitted and reflected. ^ C. You are correct ^ D. No, some of it goes into the second material while some of it is reflected.

@ When using focused transducers, non-symmetry in a propagated sound beam may be caused by: \d | A. Backing material variations | B. Lens centering or misalignment | C. Porosity in lenses | D. All of the above ^ A. Yes, but there could also be other causes. ^ B. Yes, but there could also be other causes. ^ C. Yes, but there could also be other causes. ^ D. You are correct. @ Ultrasonic wheel units may be used for which of the following types of examination? \d | A. Straight or longitudinal examination | B. Angle-beam or shear wave examination | C. Surface wave or Rayleigh wave | D. All of the above ^ A. Yes, but other answer choices apply as well. ^ B. Yes, but other answer choices apply as well. ^ C. Yes, but other answer choices apply as well. ^ D. You are correct. @ During straight beam testing, test specimens with non-parallel front and back surfaces can cause:

\a | 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. You are absolutely correct. ^ B. Sorry, this is incorrect. Lack of parallelism will affect signal amplitude. ^ C. This is possible but there is a more profound affect on the amplitude. ^ D. No, there is a more profound affect on the amplitude. @ 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. \b | A. Is equal to the time required for the sound to travel through the piece. | B. Is greater than the time required for the sound to travel through the testpiece. | C. Is less than the time required for the sound to travel through the test piece. | D. None of the above. ^ A. Yes, but this will cause a lot of confusion, since the signals will be superimposed.

^ B. Absolutely right. ^ C. No, this answer is incorrect. ^ D. No, there is a valid answer. @ In a B-scan display, the length of a screen indication from a discontinuity is related to: \b | 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. Both A and B | D. None of the above ^ A. No, not the length of a screen indication. ^ B. You are right ^ C. Incorrect, inspect choice A again. ^ D. No, there is a valid answer. @ Which circuit triggers the pulser and sweep circuits in an A-scan display? \c | A. Receiver-amplifier | B. Power supply | C. Clock | D. Damping ^ A. No, the receiver-amplifier modifies return signal for

display. ^ B. No, this choice is incorrect. ^ C. You are correct. ^ D. No, damping only adjusts excitation pulse width. @ On an A-scan display, the "dead zone," refers to: \c | A. The distance contained within the near field. | B. The area outside the beam spread. | C. The distance covered by the front surface pulse width and recovery time. | D. The area between the near field and the far field. ^ A. Sorry! Generally "dead zone" is much smaller than the nearfield. ^ B. Sorry! "Dead zone" is due to the pulse duration. ^ C. You've got it. ^ D. Sorry! Please try again. @ On an A-scan display, what represents the intensity of a reflected beam? \d | A. Echo pulse width | B. Horizontal screen location | C. Signal brightness | D. Signal amplitude ^ A. Sorry! Please try again.

^ B. Sorry! This gives discontinuity location. ^ C. Sorry! Signal brightness is used in B-scan to represent the intensity of reflected beam. ^ D. You are exactly right. @ Of the following scan types, which one can be used to produce a recording of flaw areas superimposed over a plan view of the test piece? \c | A. A-scan | B. B-scan | C. C-scan | D. D-scan ^ A. No, an A-scan represents the amplitude-distance relationship. ^ B. No, the B-scan represents the cross-sectional view. ^ C. You are correct ^ D. No, there is no such thing as a D-scan. @ In immersion testing in a small tank, a manually operated manipulator is used to: \d | A. Set the proper water path | B. Set the proper transducer angle | C. Set the proper index function | D. Both A and B

^ A. Yes, but it is used to do more than that. ^ B. Yes, but it is used to do more than that. ^ C. No, this choice is totally incorrect. ^ D. You are correct. @ A 45 degrees shear angle beam transducer produces a wave in the metal which is polarized: \d | A. Perpendicular to the direction of propagation and parallel to the entry surface. | B. In the direction of propagation and at 45 degrees to the normal to the entry surface. | C. Perpendicular to the entry surface. | D. Perpendicular to the direction of propagation and at 45 degree to the entry surface. ^ A. No, it is not parallel to the entry surface. ^ B. Sorry! Please try again. ^ C. No, polarization direction is related primarily to the direction of the propagation. ^ D. You are correct. @ In straight (normal) beam contact testing, a reduction in the back surface reflection amplitude could indicate: \d | A. Inadequate coupling. | B. A flaw which is not normal to the beam.

| C. A near surface defect that cannot be resolved from the main bang (initial pulse). | D. All of the above ^ A. Yes, but there could be several other reasons too. ^ B. Yes, but there could be several other reasons too. ^ C. Yes, but there could also be several other reasons. ^ D. You are absolutely correct. @ In an automatic scanning immersion unit, the bridge or carriage serves to: \a | 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 tube. | C. Control the vertical and angular positioning of the scanner tube. | D. Raise and lower the transducer. ^ A. Absolutely correct. ^ B. No, bridge or carriage cannot be used to angulate. ^ C. No, bridge or carriage cannot be used to angulate. ^ D. No, bridge and carriage cannot be used to raise and lower the transducers. @ When adjusting the flaw locating rule for a shear wave weld inspection, the zero point on the rule must coincide with the:

\a | A. Sound beam exit point of the wedge | B. Point directly over the flaw | C. Wheel search unit | D. Circular scanner ^ A. Outstanding ^ B. Sorry! This choice is irrelevant. ^ C. Sorry! Please try again. ^ D. Sorry! This choice is irrelevant. @ A special scanning device with the transducer mounted in a tire- like container filled with couplant is commonly called; \c | A. A rotating scanner | B. An axial scanner | C. A wheel search unit | D. A circular scanner ^ A. No, but you are on the right track. ^ B. No, it rotates. ^ C. You are correct. ^ D. Sorry! Please try again. @ Which best describes a typical display of a crack whose major surface is perpendicular to the ultrasonic beam? \b | 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. No, since the beam is perpendicular to the crack, indication is not broadened. ^ B. You are absolutely correct. ^ C. No, it will definitely show because of most favorable orientation. ^ D. No, since the beam is perpendicular to the crack, indication is not broadened. @ Compensation for the variation in echo height related to variations in discontinuity depth in the test material is known as: \c | A. Transfer | B. Attenuation | C. Distance amplitude correction | D. Interpretation ^ A. Sorry! Your choice is incorrect. ^ B. No, attenuation causes change in the amplitude as the sound propagates. ^ C. Absolutely correct. ^ D. Sorry! Your choice is incorrect. @ Which of the following is a reference reflector that is not dependent on beam angle

\c | A. A flat bottomed hole | B. A vee notch | C. A side drilled hole which is parallel to the plate surface and perpendicular to the sound path | D. A disc shaped laminar reflector ^ A. No, it certainly depends on beam angle. It is useful only for a zero degree angle. ^ B. No, it certainly depends on beam angle. It is useful for angle beam testing. ^ C. You got it ^ D. No, it certainly depends on beam angle. It is useful only for a zero degree angle. @ During a straight beam ultrasonic test a discontinuity indication is detected which is small in amplitude compared to the loss in amplitude of back reflection. The orientation of this discontinuity is probably: \d | A. Parallel to the test surface. | B. Parallel (plus or minus 5 degrees) from the test surface. | C. Parallel to the sound beam. | D. Such that complete loss of back reflection will result. ^ A. No, if it was parallel, it should have given a large indication.

^ B. Sorry! Please try again. ^ C. No, if it were parallel to the sound beam, loss of back surface reflection should be very small. ^ D. You are correct. @ 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: \b | 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. No, large indications would be obtained if it were perpendicular ^ B. Outstanding ^ C. No, apply the golden rule of ultrasonics. ^ D. No, you are not on the right track. @ Gas discontinuities are reduced to flat discs or other shapes parallel to the surface by: \a | A. Rolling | B. Machining | C. Casting | D. Welding

^ A. You are correct. ^ B. No, machining can't make them flat or parallel to the surface. ^ C. No, casting typically produces bubbles which are spherical. ^ D. No, welding typically produces bubbles which are spherical. @ In which zone does the amplitude of an indication from a given discontinuity diminish exponentially as the distance increases? \a | A. Far field zone | B. Near field zone | C. Dead zone | D. Fresnel zone ^ A. You are correct. ^ B. No, in near field amplitude changes rapidly. ^ C. No, you can not find the defect in this zone, so question of amplitude change is irrelevant. ^ D. No, in the fresnel zone, amplitude changes rapidly. @ A smooth flat discontinuity whose major plane is not perpendicular to the direction of sound propagation may be indicated by: \d | A. An echo amplitude comparable in magnitude to the back surface reflection.

| B. A complete loss of the back surface reflection. | C. An echo amplitude larger in magnitude than the back surface reflection. | D. All of the above. ^ A. Yes, but there are other possibilities. ^ B. Yes, but there are other possibilities. ^ C. Yes, but there are other possibilities. ^ D. You are correct. @ 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: \b | 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. No, signal linearity is not related to angle. ^ B. You are absolutely correct. ^ C. No, this answer is wrong. Curved discontinuity can cause focussing, but not plane discontinuity. ^ D. No, this answer is wrong. @ As transducer diameter decreases, the beam spread: \c | A. Decreases

| B. Remains the same | C. Increases | D. Becomes conical in shape ^ A. No, beam spread is a function of wavelength / transducer diameter. ^ B. No, beam spread is a function of wavelength / transducer diameter. ^ C. You are correct. ^ D. Sorry! Please try again. @ A set of standard reference blocks with the same geometrical configuration and dimensions other than the size of the calibration reflectors, e.g., flat bottom holes, is called a set of: \b | A. Distance/amplitude standards. | B. Area/amplitude standards. | C. Variable frequency blocks. | D. Beam spread measuring blocks. ^ A. No, in this type size of reflector remains constant. ^ B. You are correct. ^ C. Sorry! Such a thing does not exist in UT. ^ D. Sorry! Please try again. @ The angle at which 90 degree refraction of a longitudinal sound wave is reached is called: \b

| A. The angle of incidence. | B. The first critical angle. | C. The angle of maximum reflection. | D. The second critical angle. ^ A. No, angle of incidence can be any angle from 0 to 90 degrees. ^ B. You are right. ^ C. No. Think harder. ^ D. No, at second critical angle, shear waves reach 90 degree angle of refraction. @ Which of the following controls the voltage supplied to the vertical deflection plates of the CRT in an A-scan UT setup? \c | A. Sweep generator | B. Pulser | C. Amplifier circuit | D. Clock timer ^ A. No, sweep generator controls horizontal deflection plates. ^ B. No, pulser excites the transducer. ^ C. You are right. ^ D. Sorry! Try again. @ 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 which can include: \d | A. Beam spread | B. Couplant mismatch | C. Test piece geometry | D. All of the above ^ A. True, but there are other mechanisms also. ^ B. True, but there are other mechanisms also. ^ C. True, but there are other mechanisms also. ^ D. You are exactly right. @ The vertical linear range of a test instrument may be determined by obtaining ultrasonic responses from: \c | A. A set of distance-amplitude reference blocks. | B. Steel balls located at several different water path distances. | C. A set of area-amplitude reference blocks. | D. All of the above. ^ A. No, distance should be kept constant. ^ B. No, distance should be kept constant. ^ C. You are correct. ^ D. No, not all are true. @ Large grains in a metallic test specimen usually result in: \d

| A. Decrease or loss of back surface reflection. | B. Large "hash" or noise indications. | C. Decrease in penetration. | D. All of the above. ^ A. You are partially correct. ^ B. You are partially correct. ^ C. You are partially correct. ^ D. You are absolutely correct. @ The total energy losses occurring in all materials is called: \a | A. Attenuation | B. Scatter | C. Beam spread | D. Interface ^ A. Outstanding ^ B. No, this is one of the reasons which causes energy loss. ^ C. No, this is one of the reasons which causes energy loss. ^ D. No, this is one of the reasons which causes energy loss. @ Delay-tip(stand-off)type contact search units are primarily used for: \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. 231.

@ 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. 232.

@ The attenuation of energy within a material in the far field

of the ultrasonic beam may be expressed as the: \d | 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. @ For aluminum and steel the longitudinal velocity is approximately _________ the shear velocity: \b | A. Equal to | B. Twice | C. One-half of | D. Four times

^ A. Incorrect, shear wave velocity is much smaller than longitudinal wave velocity. ^ B. You are absolutely correct. ^ C. Incorrect, shear wave travel slower than longitudinal waves. ^ D. Incorrect. You are close. @ Water travel distance for immersion inspections should be: \a | A. Such that the second front reflection does not appear between the first front and back reflections. | B. Exactly 3 inches. | C. Less than 3 inches. | D. Always equal to the thickness of the material being inspected. ^ 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. 233.

@ 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 | A. An electronic gate. | B. An electronic attenuator.

| C. A distance amplitude correction circuit. | D. A fixed marker. ^ A. Outstanding ^ B. No. Attenuator attenuates the signal and does not do selection. ^ C. Sorry! Please try again. ^ D. Sorry! DAC is applied throughout the thickness of material. @ When conducting a contact ultrasonic test, the "hash" or irregular signals that appear in the CRT display of the area being inspected could be caused by: \c | 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. No, hash is directly proportional to grain size. ^ B. No, in contact testing, dirt in water couplant is not a major problem. ^ C. You are correct. ^ D. No. This will reduce back surface reflection. Hash is related to grain structure. @ In inspecting a 4-inch diameter threaded steel cylinder for radial cracks extending from the root of the threads, it would be

preferable to transmit: \b | 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. No, You will get too many reflections from threads. ^ B. You are correct. ^ C. Incorrect. How do you launch surface waves perpendicular to the direction of thread roots ^ D. Incorrect. How do you launch shear waves around the circumference of the cylinder @ In an immersion inspection of raw material, the water travel distance should be: \c | A. Exactly 3 inches. | B. Equal to 3 inches (plus or minus 1/2 inch). | C. Equal to the water travel distance used in setting up on the reference standards. | D. Equal to the thickness of a material. ^ A. Incorrect. Water traveling distance depends on material thickness and wave velocity. ^ B. Incorrect. Water traveling distance depends on material

thickness and wave velocity. ^ C. You are correct. ^ D. No, this can cause a confusing screen presentation. @ 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: \b | A. The angle of incidence. | B. The angle of refraction. | C. The angle of rarefaction. | D. The angle of reflection. ^ A. No, Angle of incidence is in the host medium. ^ B. You've got it. ^ C. No, there is no such angle. ^ D. No, angle of reflection is in the same host medium as the angle of incidence. @ The process of adjusting an instrument or device to a reference standard is referred to as: \d | A. Angulation | B. Scanning | C. Correcting for distance-amplitude variations | D. Calibration ^ A. No, angulation is done in immersion testing to get peak

amplitude signal. ^ B. Sorry! Scanning involves moving transducer back and forth over a sample, usually in immersion mode. ^ C. Sorry! Your choice is incorrect. ^ D. You're right. @ An electron tube in which a beam of electrons from the cathode is used to reproduce an image on a fluorescent screen at the end of the tube is referred to as: \c | A. An amplifier tube | B. A pulser tube | C. A cathode ray tube | D. A sweep tube ^ A. Incorrect. There is no such thing in UT. ^ B. Incorrect. There is no such thing in UT. ^ C. You are correct. ^ D. Incorrect. There is no such thing in UT. @ A grouping of a number of crystals in one search unit, with all contact surfaces in the sample plane, and vibrating in phase with each other to act as a single transducer is called a: \b | A. Focusing crystal | B. Crystal mosaic | C. Scrubber

| D. Single plane manipulator ^ A. Sorry! Please try again. ^ B. Excellent ^ C. Sorry! Please try again. ^ D. Sorry! Please try again. @ The scattering of the ultrasonic energy of an ultrasonic beam due to reflection from a highly polished surface is called: \b | A. Angulation | B. Dispersion | C. Refraction | D. Rarefaction ^ A. Sorry! Please try again. ^ B. You are absolutely correct. ^ C. No, refraction occurs when two medias are involved. ^ D. No, rarefaction is associated with the way longitudinal wave propagates. @ The angle of reflection is: \a | 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. You are correct.

^ B. No, apply Snell's law. ^ C. No, apply Snell's law. ^ D. No, apply Snell's law. @ The angular position of the reflecting surface of a planar discontinuity with respect to the entry surface is referred to as: \c | A. The angle of incidence. | B. The angle of refraction. | C. The orientation of the discontinuity. | D. None of the above. ^ A. No, angle of incidence is associated with the wave. ^ B. No, angle of incidence is associated with the wave. ^ C. You are right. ^ D. Sorry! Your choice is incorrect. @ A short burst of alternating electrical energy is called: \d | A. A continuous wave | B. A peaked DC voltage | C. An ultrasonic wave | D. A pulse ^ A. No, continuous wave is not short. ^ B. No, look at the key word "alternating" ^ C. Incorrect. Ultrasonic wave is not electric energy. ^ D. Super! You are absolutely correct.

@ In ultrasonic testing, the time duration of the transmitted pulse is referred to as: \a | A. The pulse length or pulse width | B. The pulse amplitude | C. The pulse shape | 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. @ The phenomenon by which a wave strikes a boundary and changes the direction of its propagation within the same medium is referred to as: \d | A. Divergence | B. Impedance | C. Angulation | D. Reflection ^ A. No, divergence is a function of wavelength/transducer diameter ^ 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 passes from one medium to another whose velocity differs from that of the first medium is called: \a | A. Refraction | B. Rarefaction | C. Angulation | D. Reflection ^ A. You've got it. ^ B. No, rarefaction is associated with the way longitudinal wave propagates. ^ C. Sorry! This answer is incorrect. ^ D. No, reflection occurs within the same medium. @ The coated inside surface of the large end of a cathode ray tube which becomes luminous when struck by an electron beam is called: \c | A. An electron gun | B. An electron amplifier | C. A CRT screen | D. An electron counter ^ 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." 234. 235. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 236.

ULTRASONICS TESTING LEVEL III

237. @ Notches are frequently used as reference reflectors for: \a | A. Distance-amplitude calibration for shear waves. | B. Area-amplitude calibration. | C. Thickness calibration of plate. | D. Determining near-surface resolutions. ^ A. You are correct. ^ B. No, flat bottom holes are used for area-amplitude calibration. ^ C. No, step block is used for thickness calibration. ^ D. No, notches are used for defect detection. @ Notches provide good reference discontinuities when UT examination is conducted to primarily detect defects such as: \b | A. Porosity in rolled plate. | B. Inadequate penetration at the root of a weld. | C. Weld porosity. | D. Internal inclusions.

^ A. No, notches are used for surface breaking defects. ^ B. You are correct. ^ C. No, notches are used for surface breaking defects. ^ D. No, notches are used for surface breaking defects. @The difference between a compression and shear wave is: \b | A. Quantitative measure | B. Particle direction | C. Qualitative measure | D. Amplitude ^ A. No, the difference is in the way the particles oscillate. ^ B. You are right. ^ C. No, the difference is in the way the particles oscillate. ^ D. No, the difference is in the way the particles oscillate. @ The particle motion for Rayleigh waves is usually described as: \c | A. Sinusoidal | B. Circular | C. Elliptical | D. Shear ^ A. Sorry! Please try again. ^ B. No, none of the waves have circular particle motion. ^ C. You are correct. ^ D. No, shear describes wave mode. The question asks for

particle motion. @ Based upon wave theory and ignoring attenuation losses, the echo amplitude is: \d | A. Directly proportional to the distance to the reflector. | B. Inversely proportional to the distance to the reflector. | C. Directly proportional to the square of the distance to the reflector. | D. Inversely proportional to the square of the distance to the reflector. ^ A. No, signal amplitude decreases rapidly with the distance. ^ B. No, signal amplitude decreases rapidly with the distance. ^ C. No, signal amplitude decreases rapidly in the distance. ^ D. You are correct. @ The rate generator in B-scan equipment will invariably be directly connected to the: \b | A. CRT intensity circuit | B. Pulser circuit | C. RF amplifier circuit | D. Horizontal sweep circuit ^ A. Sorry, you are mistaken. ^ B. You got it ^ C. No, RF amplifier circuit is not correct.

^ D. Sorry! Please try again. @ In A-scan equipment, the RF pulser output voltage is normally in the range of: \c | A. 1-10 volts. | B. 10-100 volts. | C. 100-1000 volts. | D. 1000-3000 volts. ^ A. No, this voltage is too low for the given application. ^ B. No, but you are close. ^ C. You are correct. ^ D. Sorry! These values are too high. @ When contact testing, an increase in tightness of a shrink fit to a hollow shaft will cause the ratio of the back reflection to the metal-to-metal interface reflection to: \a | A. Increase | B. Decrease | C. Remain unchanged | D. Cannot be predicted as the response is material-dependent. ^ A. You are correct. ^ B. Sorry! Signal amplitude from the shrink fit decreases. ^ C. No, it does predictable change. ^ D. Sorry! It can be predicted.

@ During the inspection of a parallel-sided, machined forging using the straight beam immersion technique, a diminished back reflection in a localized area in the absence of a defect indication would least likely represent: \d | A. A coarse grain structure | B. Small nonmetallic stringers | C. A defect oriented at a severe angle to the entry surface | D. A large inclusion ^ A. No, coarse grain structure should show as hash. ^ B. No, this should give a large defect indication. ^ C. No, you could still get back surface indication. It depends on the size. ^ D. You are right. @ As you increase the frequency of a given size transducer: \c | A. The lateral resolution is impaired | B. The beam divergence increases | C. The length of the near field increases | D. The sensitivity increases ^ A. Sorry! With increase in frequency lateral resolution should improve. ^ B. No, beam divergence decreases. Beam divergence is a function of Wavelength / Diameter.

^ C. You are correct. ^ D. No, you have answered incorrectly. @ In an ultrasonic test system where signal amplitudes are displayed on a CRT, an advantage of a frequency-independent attenuator over a continuously variable gain control is that: \b | A. The pulse shape distortion is less. | B. The signal amplitude measured using the attenuator is independent of frequency. | C. The dynamic range of the system is decreased. | D. The effect of amplification threshold is avoided. ^ A. True, but amplitude is also greatly affected. ^ B. You've got it. ^ C. No, you missed it. ^ D. You are mistaken. @ An amplifier in which received echo pulses must exceed a certain threshold voltage before they can be indicated might be used to: \a | A. Suppress amplifier noise, unimportant scatter echoes, or small flaw echoes which are of no consequence. | B. Provide a screen display with nearly ideal vertical linearity characteristics. | C. Compensate for the unavoidable effects of material

attenuation losses. | D. Provide distance amplitude correction automatically. ^ A. You are absolutely correct. ^ B. Sorry! Please try again. ^ C. Sorry! Please try again. ^ D. No, a variable gain is used for DAC correction. @ The transmitted pulse at the output of the pulser usually has a voltage of 100 to 1000 V, whereas the voltages of the echo at the input of the amplifier are on the order of: \c | A. 10 volts | B. 50 volts | C. .001 to 1 volts | D. 1 to 5 volts ^ A. No, that's too high. ^ B. No, that's too high. ^ C. You've got it. ^ D. No, but you are close. @ The output voltage from a saturated amplifier is: \c | A. 180 degrees out of phase from the input voltage. | B. Lower than the input voltage. | C. Nonlinear with respect to the input voltage. | D. Below saturation .

^ A. No, the question does not concern phase. ^ B. Sorry, your answer is incorrect. ^ C. Outstanding ^ D. No, the key word is "saturation. @ The intended purpose of the adjustable calibrated attenuator of an ultrasonic instrument is to: \b | A. Control transducer damping. | B. Increase the dynamic range of the instrument. | C. Broaden the frequency range. | D. Attenuate the voltage applied to the transducer. ^ A. No, increase operational range. ^ B. Excellent! You are correct. ^ C. No, the attenuator should not affect the frequency range. ^ D. No, not the voltage applied to the transducer, but to increase operational range. @ Which of the following might result in increased transmission of ultrasound within a coarse-grained material? \b | A. Perform the examination with a smaller diameter transducer. | B. Perform the examination after a grain refining heat treatment. | C. Change from a contact examination to an immersion

examination. | D. Change from a longitudinal to a transverse wave. ^ A. No, but a lower frequency might work. ^ B. You've got it. ^ C. No, that should have minimal effect, if any. ^ D. Sorry! Since for same frequency, wavelength is reduced, therefor transmission will be poorer. @ When material grain size is on the order of ________ wavelength or larger, excessive scattering of the ultrasonic beam may affect test results. \c | A. 1 | B. 1/2 | C. 1/10 | D. 1/100 ^ A. No, this will cause very high attenuation. ^ B. No, but you are close. ^ C. You are absolutely correct. ^ D. No, since the grain size is much smaller than the wavelength, the result is low attenuation. @ In a forging, flaws associated with nonmetallic inclusions can most accurately be described as having which of the following orientations? \c

| A. Parallel to the major axis. | B. Parallel to the minor axis. | C. Aligned with forging flow lines. | D. At approximately 45 degrees to the forging direction. ^ A. No, flaws are in the direction of the forging. ^ B. No, flaws are in the direction of the forging. ^ C. Excellent ^ D. No, the flaws are in the direction of the forging. @ In a long rod which is examined from one end with a longitudinal beam, the most likely effect of longitudinallyoriented discontinuities would be to: \c | A. Significantly reduce the back surface reflection. | B. Cause echoes between initial pulse and the first back surface Reflection for which reflector placing can't be precisely found. | C. Remove or reduce the amplitude of echoes from refracted beam paths. | D. Cause excessive baseline noise. ^ A. No. Presence of longitudinally-oriented tight discontinuities will not have any effect on back surface reflection. ^ B. No, but you are close. ^ C. You've got it.

^ D. No, there should not be an increase in baseline noise. @ When maximum sensitivity is required from a transducer: \c | A. A straight-beam unit should be used. | B. Large diameter crystals are required. | C. The piezoelectric element should be driven at its fundamental resonant frequency. | D. The band width of the transducer should be as large as possible. ^ A. No, this choice has no direct relation to sensitivity. ^ B. No, this choice has no direct relation to sensitivity. ^ C. Absolutely right. ^ D. No, this will reduce sensitivity. @ Which of the following 1 MHz search units should normally have the best time or distance resolution? \d | A. Quartz transducer with air backing | B. Quartz transducer with phenolic backing | C. Barium titanate transducer with phenolic backing | D. Lithium sulfate transducer with epoxy backing ^ A. No, more damping is required and it is not the best material. ^ B. No, Quartz is not the best material. ^ C. No, but you are close.

^ D. Outstanding!! You are correct. @ The sensitivity of an ultrasonic test system: \a | A. Depends on the search unit, pulser, and amplifier used. | B. Decreases as the frequency is increased. | C. Increases as the resolution increases. | D. Is not related to mechanical damping or the transducer. ^ A. You are absolutely right. ^ B. No, it depends on several factors. ^ C. No, it depends on several factors. ^ D. No, it depends on several factors. @ The ability of a test system to separate the front-surface echo and the echo from a small discontinuity just below the surface: \a | A. Depends primarily upon the shape of the initial pulse from the transducer. | B. Is not related to the surface roughness of the part under inspection. | C. Is primarily related to the thickness of the part under inspection. | D. Is usually improved by using a larger diameter search unit. ^ A. Excellent!! You are right. ^ B. No, surface roughness does affect the result.

^ C. No, it is not primarily related to part thickness. ^ D. No, you are off. @ Search unit sensitivity is most often determined by: \b | A. Calculations based on frequency and thickness of piezoelectric element. | B. The amplitude of the response from an artificial discontinuity. | C. Comparing it to a similar search unit made by the same manufacturer. | D. Determining the ringing time of search unit. ^ A. No, sensitivity is related to amplitude. ^ B. You've got it. ^ C. Although this one way, it is not a good way. ^ D. No, sensitivity is related to amplitude. @ Which frequency can best distinguish the difference between a large planar defect and 4 stacked (multiple-layered) laminations in rolled plate? \d | A. 0.5 MHz | B. 1 MHz | C. 2.25 MHz | D. 5 MHz ^ A. No, higher frequency resolves better.

^ B. No, higher frequency resolves better. ^ C. No, but you are close. ^ D. You are absolutely correct. @ During immersion examination, when evaluating the response from a contoured surface of a part, irrelevant indications due to the contour are most likely to appear as: \c | A. Sharp spiked signal indications | B. Irregular signal indications | C. Broad-based signal indications | D. Hash ^ A. No, cracks and flat surfaces give sharp indications. ^ B. Sorry, your answer is wrong. ^ C. You are absolutely right. ^ D. Sorry! Hash is normally due to large grain scattering. @ The pulse applied to the electrodes of the ultrasonic search unit is: \a | A. Electrical | B. Mechanical | C. Electro-mechanical | D. Piezoelectrical ^ A. Outstanding ^ B. No. How do you excite the transducer

^ C. Sorry! Try again. ^ D. Sorry! This choice is incorrect. @ In calibrating an ultrasonic test instrument utilizing the responses from each of the area/amplitude type reference blocks, the determination of the: \a | A. Vertical range is obtained | B. Pulse range is obtained | C. Resolving range is obtained | D. Horizontal range is obtained ^ A. You are right. ^ B. Sorry! Your answer is wrong. ^ C. Sorry! This answer is incorrect. ^ D. Sorry, your answer is incorrect. @ Test sensitivity corrections for metal distance and discontinuity area responses are accomplished by using: \b | A. An area/amplitude set of blocks. | B. An area/amplitude and a distance/amplitude set of blocks. | C. A distance/amplitude set of blocks. | D. Steel balls of varying diameter. ^ A. No, you failed to consider metal distance corrections. ^ B. You've got it. ^ C. No, you neglected area corrections.

^ D. Sorry! This answer is incorrect. @ The time from the start of the ultrasonic pulse until the reverberations completely decay limits the maximum usable: \c | A. Pulse time-flaw rate | B. Pulser/receiver rate | C. Pulse repetition rate | D. Modified pulse-time rate ^ A. No, there is no such thing. ^ B. No, there is no such thing. ^ C. You are absolutely correct. ^ D. Sorry, this choice is incorrect. @ Rough surfaces can cause undesirable effects which are noticeable when parts are tested ultrasonically, including: \b | A. Requiring less viscous couplant | B. An increase in the width of front face echo and consequent loss of resolving power. | C. Acoustical mismatch. | D. Larger inspection frequency ^ A. No, this will accentuate the problem. ^ B. You've got it. ^ C. Sorry! Your answer is wrong. ^ D. No, this will accentuate the problem.

@ Rough surfaces cause the echo amplitude from discontinuities within the part to: \b | A. Increase | B. Decrease | C. Not change | D. Change frequency ^ A. No, energy is scattered. ^ B. You are absolutely right. ^ C. No, energy is scattered. ^ D. Sorry! Please try again. @ When a sound beam travels from a liquid into a metal through a contoured surface, the sound beam inside the metal will: \d | A. Have larger beam diameter | B. Have same beam diameter. | C. Not be effected by the part geometry. | D. Be convergent if the surface is concave, and divergent if the surface is convex. ^ A. No, it depends on the curvature. ^ B. No, curved part will affect focussing characteristics. ^ C. No, curved part will affect focussing characteristics. ^ D. Excellent!! You are exactly right. @ The resonant frequency of a 2 cm thick plate of Naval brass

(V=443000 cm/sec) is: \d | A. .903 MHz | B. .443 MHz | C. .222 MHz | D. .111 MHz ^ A. No, recalculate your figures. Frequency = velocity x (thickness / 2) ^ B. No, recalculate your figures. Frequency = velocity x (thickness / 2) ^ C. No, recalculate your figures. Frequency = velocity x (thickness / 2) ^ D. You've got it. @ Resonance testing equipment generally utilizes: \b | A. Pulsed longitudinal waves | B. Continuous longitudinal waves | C. Pulsed shear waves | D. Continuous shear waves ^ A. Sorry! Most ultrasonic equipment utilizes pulsed waves, but not in resonance testing. ^ B. You are absolutely correct. ^ C. Sorry! Try again. ^ D. No. Not generally, but this can be done.

@ Preventing the decrease of sensitivity close to a wall which is parallel to the beam direction, the probe used should be: \d | A. As small as possible | B. Of as low frequency | C. Both A and B above | D. Large and with a frequency as high as possible ^ A. Sorry! Your answer is incorrect. Use Beam divergence relationship. ^ B. Incorrect. Use Beam divergence relationship. ^ C. Incorrect. Use beam divergence relationship. ^ D. Excellent! You are correct. @ Some information on the shape of a flaw may be given by: \c | A. The shape of the echo | B. The amplitude of the echo | C. Both A and B above | D. Neither A nor B above ^ A. True, but there is more to it. ^ B. True, but there is more to it. ^ C. You've got it. ^ D. Sorry! This choice is incorrect. @ Which of the following transducer materials makes the best transmitter

\c | A. Quartz | B. Lithium sulfate | C. Barium titanate | D. None of the above ^ A. Sorry! Please try again. ^ B. No, lithium sulfate is the best receiver. ^ C. Absolutely right. ^ D. Incorrect. @ Of the transducer materials listed below, the most efficient receiver is: \b | A. Quartz | B. Lithium sulfate | C. Barium titanate | D. Lead meta-niobate ^ A. Sorry! This choice is incorrect. ^ B. Outstanding ^ C. No, this the best transmitter. ^ D. Sorry! You've answered incorrectly. @ The concentration of energy in the far field of a transducer beam: \b | A. Is greatest at the outer edges of the beam.

| B. Is greatest at the center of the beam. | C. Is the same at the outer edges as in the center of the beam. | D. Is directly proportional to beam width. ^ A. No, it is least at the edges. ^ B. You've got it. ^ C. Sorry! Please try again. ^ D. Sorry, you are wrong. @ Typical applications of shear waves in ultrasonic testing is the inspection of: \d | A. Welds | B. Plate | C. Pipe and tubing | D. All of the above ^ A. No, you can do much more than just inspect welds. ^ B. No, you can do much more than just inspect plates. ^ C. No, you can do much more than just inspect pipe and tubing. ^ D. Absolutely correct. @ In angle beam shear wave testing, skip distance will ______ as the thickness of the test specimen is increased. \c | A. Decrease

| B. Not change | C. Increase | D. Decrease by half with double thickness ^ A. No, skip distance is directly proportional to thickness. ^ B. No, skip distance is directly proportional to thickness. ^ C. You are correct. ^ D. Sorry, you missed it. @ The thickness range of UT resonance thickness gages can be increased by: \c | A. Using large transducers | B. Operating at the fundamental frequency | C. Operating at a harmonic frequency | D. Increasing the voltage. ^ A. No, the transducer size does not affect ranges. ^ B. No, that does not increase testing range. ^ C. You've got it. ^ D. Incorrect, this will only increase signal strength but not the range. @ The ability of transducers to detect echoes from small defects is a definition for: \b | A. Resolution | B. Sensitivity

| C. Definition | D. Gain ^ A. No, resolution is to resolve closely spaced defects. ^ B. Excellent ^ C. Sorry, you missed it. ^ D. Sorry! Your answer is incorrect. @ The length of the near field for a 2.5 cm diameter, 5 MHz transducer placed in oil (V=140000 cm/sec) is approximately: \c | A. .028 cm | B. 6.25 cm | C. 55.8 cm | D. 22.3 cm ^ A. No, apply N=(D**2)/(4* Wavelength) ^ B. No, apply N=(D**2)/(4* Wavelength) ^ C. You've got it. ^ D. No, apply N=(D**2)/(4* Wavelength) @ From the equation for the length of the near field, it can be determined that the near field can be minimized by: \d | A. Decreasing water travel distance | B. Increasing transducer diameter | C. Decreasing the size of the reference targets. | D. Decreasing test frequency.

^ A. No, apply N=(D**2)/(4* Wavelength ^ B. No, this will increase near field distance. Apply N=(d**2)/(4 * wavelength) ^ C. No, apply N=(D**2)/(4* Wavelength) ^ D. Super! You've got it. @ The acoustic impedance for brass (V=443000 cm/sec,p=8.42 gm/cc) is: \d | A. 53000 (gm/(cm sq. sec) | B. 940000 (gm/(cm sq. sec) | C. 19000 (gm/(cm sq. sec) | D. 3730060 (gm/(cm sq. sec) ^ A. No, acoustic impedance=velocity * density ^ B. No, acoustic impedance=velocity * density ^ C. No, acoustic impedance=velocity * density ^ D. You've got it. @ The principal attributes that determine the differences in ultrasonic velocities among materials are: \c | A. Frequency and wavelength | B. Thickness and travel time | C. Elasticity and density | D. Chemistry and permeability ^ A. No, ultrasonic velocity is dependent on material

properties. ^ B. No, ultrasonic velocity is dependent on material properties. ^ C. You are absolutely correct. ^ D. No, ultrasonic velocity is dependent on material properties. @ What would be the wavelength of the waves in lead (V=210000 cm/sec)if it is tested with a 25 MHz transducer? \d | A. 119 cm | B. 0.525 cm | C. 0.0119 cm | D. 0.0084 cm ^ A. Apply velocity = frequency x wavelength ^ B. Apply velocity = frequency x wavelength ^ C. Apply velocity = frequency x wavelength ^ D. You've got it. @ What is the transducer half-angle beam spread of a l.25 cm diameter, 2.25 MHz transducer in water (V=150000 cm/sec? \c | A. 2.5 degrees | B. 40.5 degrees | C. 3.75 degrees | D. 37.5 degrees

^ A. Sorry! Please try again. ^ B. Sorry! Please try again. ^ C. You've got it. ^ D. Sorry! Please try again. @ The term that is used to determine the relative transmittance and reflectance of ultrasonic energy at an interface is called: \c | A. Acoustic attenuation | B. Interface refraction | C. Acoustic impedance ratio | D. Acoustic frequency ^ A. Incorrect. Attenuation is caused by grain scattering and absorption. ^ B. Sorry! Please try again. ^ C. You are absolutely right. ^ D. Sorry! Please try again.