1.ULTRASONICS TESTING LEVEL I2.@ The reference holes in standard aluminum area-amplitudeultrasonic 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 vibrationstravel 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. Excellent4.@ A term used to describe numerous small indications on thecathode 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 anultrasonic 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 testmaterial in the form of repetitive bursts of acoustic energy iscalled: \ 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 tosimulate 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 thickaluminum plate lie parallel to the entry surface at a depth of 3inches, 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 specificindication 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 thefollowing frequencies will generate a sound wave that will be mosteasily 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 thickestcrystal? \ 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 resultfrom: \ 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 standoffbetween the transducer element and the test piece are commonly usedfor: \ 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 transducerelements 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 adapterslocated in front of the transducer element. These adapters arereferred 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 ina 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 ofsome ultrasonic testing instruments that permits measurement ofdistances 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 testingsystem to distinguish between the entry surface response and theresponse 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. Excellent20.@ The phenomenon whereby an ultrasonic wave changes directionwhen the wave crosses a boundary between materials with differentvelocities 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 theinspection 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 materialand the density of the material is the factor that determines theamount of reflection or transmission of ultrasonic energy when itreaches 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 andwhose 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 oftenreferred 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 andsecond critical angles, the ultrasonic wave mode within the partwill 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 amaterial 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 thereceiving transducer and often modify the signals into a formsuitable 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 ultrasonicexamination 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 receivingtransducer into a form suitable for display on an oscilloscope orother 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 tothe 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 ultrasonicinstrument 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 examinationis 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 ofthe 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 unitsthat 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 amechanical 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 highspeed 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 spansthe 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 toadjust 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 recordof 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 effectin 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 arough reflecting surface perpendicular to the incident wave willhave what effect on the detected signal in comparison to a smoothflat-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 longitudinalmode 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 givenhomogeneous material is .625 cm/micro sec. at 1/2 inch below thesurface, 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 modewave 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 defectsignals are essential to any nondestructive test. A common methodfor 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 echoamplitude is usually ____________ from that observed for a flatdefect, 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 orientedat an angle to the entry surface so that the sound beam will strikethe 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 belowthe 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 blockare 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 apart, 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 withan excessively high pulse repetition rate, which of the followingmay 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 thefollowing? \ 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 approximatelyone-fourth the velocity in aluminum or steel. Therefore theminimum 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 representsthe 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 oftenvaried to transmit sound into the test part at various angles tothe 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 searchunit is specially designed so that one conductor is centered insideanother. 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 astandard 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 testsurface to permit or improve the transmission of ultrasonicvibrations from the search unit to the material being tested iscalled: \ 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 toproduce 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 indirect 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 thinnestquartz 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 primarilydependent 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 twodissimilar materials at an angle, a new angle of sound travel takesplace 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 ________ thevelocity 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 frequencieswould 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 likelyto produce the greatest amount of sound attenuation over a givendistance? \ 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 sometimesreferred 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-levelindications (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 oppositesurfaces 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 agiven 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 contactwith 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 thedirection 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 tothe direction of propagation, the wave being transmitted is calleda: \ 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 orautomatically 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 soundwaves 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 heightwhich can be displayed or viewed on the CRT of an ultrasonicinstrument, 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 elementis 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 usingfrequencies 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 representsthe: \ 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 providethe best penetration in a 12-inch thick specimen of coarse- grainedsteel? \ 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 unitis being conducted through the thickness of a flat part such as aplate. 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 thecrystal 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 ultrasonictesting 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 isfrequently necessary to angulate the search unit when adiscontinuity 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 ofvibration 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, theflat- 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 isnormal 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 thehuman ear are referred to as ultrasonic waves or vibrations, andthe term embraces all vibrational waves of frequency greater thanapproximately: \ 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 searchunit 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 isthat: \ 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 dirton 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 shortestwavelength 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 conductingan immersion test can remove that portion of the screenpresentation 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 mostlikely 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.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx119.ULTRASONICS TESTING LEVEL II120.@ Generally, the best ultrasonic testing method for detecting discontinuities oriented along the fusion zone in a welded plateis:\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 pulsesrepresenting the magnitude of reflected ultrasound as a functionof 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 wateris 7 degrees. The principal mode of vibration that exists in thesteel 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 byan 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 componentthat coordinates the action and timing of other components iscalled 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 thatproduces 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 voltageproducing 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 componentthat produces visible signals on the CRT which are used to measuredistance 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 partoutline 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 oflongitudinal 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 tothe 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 dampedout 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.@ 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.135.@ In contact testing, shear waves can be induced in the testmaterial 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 ofbeam 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 contactultrasonic 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 belowest?\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 intosteel at an angle of 5 degrees from the normal. In such a case therefracted 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 thefollowing 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 directednormal 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 areshown by geometric figures and the path of the signal or energy bylines 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 toescaping 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 metalwhich may be caused by the splashing, surging, interrupted pouring,or the meeting of two streams of metal coming from differentdirections 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 wavespeed 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 theinfluence 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 elasticlimit 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 absoluteor 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 andfrequency 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 beamreaches 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 it153.@ Of the piezoelectric materials listed below, the mostefficient 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 Formula154.@ Of the piezoelectric materials listed below, the mostefficient 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 atest 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 crystaland 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 isprimarily 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 proportionalto 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 ortimer 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, andscattering 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 245,000in/sec, how long does it take for sound to travel through 1 inch ofaluminum? \ 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 generallyadvisable 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 theangle-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 theuniform and repeated movement of an electron beam across thefluorescent 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 inthe 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 withlittle 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 afterscanning a part with a paintbrush transducer, it is generallynecessary 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 thinmaterials 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, theother 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 thesearch 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 beoriented: \ 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 bycontoured 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 cannotalways 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 issmaller than the diameter of the transducer, what can be usedto 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 determinedby: \ 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 approximately1/25 of the original power at a depth of: \ c171. | 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 surfaceindication before the first back reflection when inspectingaluminum by the immersion method (water is used as a couplant),it is necessary to have a minimum of at least one inch ofwater 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 searchunit 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 orvarying 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) ofultrasonic 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 througha 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 thefollowing 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 theincident 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 appearsdisjointed 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. Thethinner 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 alloyswith 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 whichfluctuations 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 reflectorsat 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 toproduce indications of fluctuating amplitude as the search unit ismoved 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 transducermay 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 thebeam divergence results in a reflection from a side of the testpiece 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 ofbeam 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.