专业英语复习题.doc

1.The thickness of any given material where 50% of the incident energy has been attenuated is known as the:A)Half-value layerB)Linear attenuation coefficientC)Decay rateD)Mass attenuation coefficient2.Radiographic inspection should be used for crack detection only whenA)The crack is largeB)The test componet is a castingC)The test component is a weldmentD)The orientation of the crack is known3.There are four types of radiation-matter interactions that can contribute to the total attenuation. These are:A)Compton scattering, pair production, photoelectric absorption, rayleigh scatteringB)Compton scattering, electron exchange, photoelectric absorption, rayleigh scatteringC)Electron exchange, pair production, photoelectric absorption, rayleigh scatteringD)None of the above4.The number of X-ray or Gamma photons that are transmitted through a material depends on the:A)Energy of the photonsB)Thickness of the materialC)Atomic number of the materialD)All of the above5.When penetrating radiation is directed at a material, the radiation intensity decreases:A) Decreases exponentially with increasing material thicknessB) Increase linearly with increasing material thicknessC) Decrease linearly with increasing material thicknessD) None of the above6.Radiographic contrast describe:A) The sharpness of lines in a radiographB) The differences in photographic density in a radiographC) The average photographic density in a radiographD) The difference in density between two different radiographs7.Image quality indicators are usually placed:A) Anywhere on the back side of the filmB) On the front side of the film near the primary area of interestC) On the front side of the test component in an area of similar thickness to the primary area of interestD) On the back side of the test component in the area of interest8.After traveling through two half-value layers, the incident radiation has been reduced to:A) 50%B) 35%C) 25%D) None of the above9.On a film radiograph, an area of high density in the test component will appear:A) Lighter than the surrounding areaB) Darker than the surrounding areaC) More defined than the surrounding areaD) Less defined than the sorrounding area10.Film contrast is determined by:A) The type of film usedB) The process by which the film was developedC) The radiation energy usedD) Both A and B11.The amount of geometric unsharpness in a radiograph is affected by:A) The source to film distanceB) The source to object distanceC) The size of the sourceD) All of the above12.Ionizing radiation can be used in industrial radiography because the health hazards:A) Have been eliminated with controls and proceduresB) Are minimized through controls and proceduresC) Are worth the riskD) Are being ignored13.Thin sheets of lead foil in contact with the film during exposure increase the film density because:A) They act as a filter to harden the radiation beamB) They reduce the amount of scatter radiationC) Incident radiation liberates electrons which help to expose the filmD) None of the above14.Which of the following does not affect radiographic contrast?A) Attenuation differences in the component being inspectedB) The wavelength of the radiaiton usedC) The amount of scattered radiationD) The level of current used for the exposure15.Lowering the energy of the radiation used to produce a radiograph will generally result in:A) Less latitudeB) Higher contrast sensitivityC) A Longer exposure timeD) All of the above16.When flaws are in unknown locations, radiography is best suited for the detection of:A) Volumetric defects such as porosityB) Tight linear defects such as cracksC) Material delaminationsD) The flaw type does not matter17.In order to have a reasonable chance at detecting a discontinuity, the reflective surface of the discontinuity must have a dimension that is at least as long as _ wavelength.A) One-halfB) OneC) TwoD) 0ne-quarter18.What type of set-up can provide information about both the size of the flaw and distance between the flaw and the transducer?A) Through transmissionB) Pitch/catch with two transducersC) Pulse echoD) Both B and C19.Shear waves do not propagate in:A) SolidsB) GasesC) LiquidsD) Both B and C are correct20.The sound energy or ultrasonic beam is more uniform in the:A) Far field zoneB) Near field zoneC) Interface between the transducer and plastic wedgeD) Band along the central axis21.The active element of most acoustic transducers used today is:A) LithiumB) Piezoelectric ceramicC) SulfideD) Quartz22.The measure of how a signal from a defect compared to other background reflections is called:A) Acoustic impedanceB) Signal to noise ratioC) RefractionD) Reflection23.Surface or Rayleigh waves travelling along the surface of relative thick solid material, penetrate to a depth of approximately:A) One wavelengthB) Two wavelengthsC) Three wavelengthsD) Infinite wavelengths24.What type of transducer contains two independently operating elements in a single housing?A) Crystal mosaic transducerB) Dual element transducerC) Liquid crystal transducerD) Bi polar transducer25.Couplant displaces the_ and makes it possible to get more sound energy into the test specimen.A) Surface rustB) Surface blemishesC) Sound energyD) Air26.Which of the following waves is able to follow a surface around a curve?A) A longitudinal waveB) A shear waveC) A surface wave27.Which of the following has a very weak and negative susceptibility to magnetic field?A) Ferromagnetic materialsB) Diamagnetic materialsC) Paramagnetic materialsD) None of the above28.When a magnetic field cuts across a crack: A) Electrons begin jumping back and forth across the crackB) The crack begins to heat upC) Magnetic poles form at the edges of the crackD) All of the above 29.A longitudinal magnetic field has magnetic lines of force that run:A) Parallel to the long axis of the partB) 90 degrees to the long axis of the partC) Transverse to the long axis of the partD) Opposite the waveform of the magnetic particle machine used30.When using the direct induction method:A) The part must be placed in the center of the coilB) Good electrical contact must be established between the test equipment and test componentC) The part may be tested in only one directionD) It is not necessary to demagnetize the part31.A material with a narrower hysteresis loop has:A) Higher reluctanceB) Lower coercivityC) Higher retentivityD) All of the above32.Magnetic lines of force:A) Almost never cross each otherB) Commonly cross each otherC) Will shift 90 degrees when a direct current is appliedD) Never cross each other33.Components generally must be demagnetized because residualmagnetism can:A) Affect machining and welding processesB) Interfere with near by electronic componentsC) Increase wear by attracting abrasive particlesD) All of the above34.A property of a material that describes the ease with which amagnetic flux is established in a component is called:A) RetentivityB) Residual magnetismC) Coercive forceD) Permeability35.A material is considered demagnetized when:A) Its residual magnetic field measures less than 5 gaussB) It no longer produces an indicationC) Its no longer attracted to a magnetD) Its residual magnetic field measures less than 3 gauss36.Magnetic particle inspection can be performed on parts made fromwhich materials?A) Iron, nickel, copperB) Iron, nickel, cobaltC) Nickel, cobalt, copperD) Iron only37.The central conductor technique is sometimes used because it:A) Allows large diameter circular parts to be completely inspected with one application of the magnetizing forceB) Produces a longitudinal field in circular partsC) Establishes a magnetic field that extends from the ID to the OD of a circular partD) None of the above38.Materials can be demagnetized by:A) Heating above thier curie temperatureB) Subjecting the component to a reversing and decreasing magnetic fieldC) Both A and BD) None of the above39.The use of prods is sometimes restricted because:A) They produce a relatively weak fieldB) There is a potential for arcing that could damage partsC) It is not possible to control the field orientationD) None of the above40.Ferromagnetic materials are made up of small polarized regions known as:A) PhotonsB) QuarksC) ElectronsD) Domains40.The advantage that liquid penetrant testing has over an unaided visual inspection is that:A) The cause of the impact can be seenB) The actual size of the discontinuity can be measuredC) The depth of the defect can be measuredD) It makes defects easier to see for the inspector42.Which of the following is a disadvantage of LPI?A) Only surface breaking flaws can be detectedB) Surface finish and roughness can affect inspection sensitivityC) Post cleaning is requiredD) All of the above43.Which of the following is an advantage to LPI?A) Large areas can be inspectedB) Parts with complex shapes can be inspectedC) It is portableD) All of the above is an advantage44.Which of the following will produce higher sensitivity of a penetrant test?A) Leaving the part immersed in the penetrant for the entire dwell timeB) Leaving the part immersed in the wet developer for the entire developer timeC) Using a nonaqueous wet developerD) Allowing the specimen to drain-dwell during its dwell time45.Water suspendible developers consist of a group of chemicals that are:A) Saturated in water and experience a chemical shift allowing it to fluoresce on the parts surfaceB) Only used on rough porous surfacesC) Dissolved in waterD) Insoluble in water but can be suspended in the water after mixing or agitation46.It is well recognized that machining, honing, lapping and hand sanding will result:A) In a better penetrant inspectionB) In a longer dwell time in order to produce adequate penetration of the penetrantC) Longer dwell timesD) Metal smearing47.Solvent suspendable developers are applied by:A) DippingB) BrushingC) SprayingD) Immersion48.The pentrants that are used to detect the smallest defects:A) Should only be used on aerospace partsB) Will also produce the largest amount of irrelevant indicationsC) Can only be used on small parts less than 10 inches in surface areaD) Should not be used in the field49.When fluorescent penetrant inspection is performed, the penetrant materials are formulated to glow brightly and to give off light at a wavelength:A) Close to infrared lightB) Close to the wavelength of x-raysC) That the eye is most sensitive to under dim lighting conditionsD) In the red spectrum50.When penetrant is first received from the manufacturer:A) A sample of fresh solution should be collected and stored as a standard for future comparisonB) It should be compared to the previous batch of penetrantC) It should be mixed with the used penetrant in order to increase its sensitivityD) It should be compared to the previous penetrants sensitivity51.Which emulsifier system is oil based?A) Hydrophilic emulsifierB) Lipophilic emulsifierC) Solvent removable emulsifierD) All of the above have an oil base52.Water soluble developers consist of a group of chemicals that are:A) Saturated in water and experience a chemical shift allowing it to fluoresce on the parts surfaceB) Only used on rough porous surfacesC) Dissolved in waterD) Not to be used on galvanized parts53.Which penetrant method is easiest to use in the field?A) Fluorescent, post-emulsifiableB) Visible dye, water washableC) Visible dye, solvent removableD) Fluorescent, water washable54.When removing excess penetrant with water, the wash time should be:A) As long as the specifications allowB) Based on the temperature of the partC) As long as necessary to decrease the background to an acceptable levelD) Longer if the water temperature increases55.Probes with iron cores tend to:A) Be more sensitive than air core probes and less affected by probe wobbleB) Be more difficult to useC) Increase the background noise of the signalD) Both B and C56.Which type of probe is most commonly sued to inspect solid products such as bar stock?A) Bobbin probesB) Surface coilsC) Encircling coilsD) Pencil probes57.The principles of operation of the most commonly used eddy current instruments are based on:A) Roentgens formulasB) Maxwells inductance bridgeC) ReciprocityD) The Inverse Square Law58.When testing for subsurface flaws, the frequency should be:As high as possibleAs low as possibleCalculated to produce a 90o difference between the liftoff and flaw signalsNone of the above59.The higher the frequency of the current used to drive the probe, the:A) More effective shielding will be due to skin effectB) Deeper the eddy currents will penetrateC) Stronger the probes magnetic field will beD) Both A and C60.When using eddy currents to measure the thickness of a nonconductive coating applied to a conductive base, the measurement is based on:A) A frequency change due to liftoffB) An impedance change due to a change in conductivityC) An impedance change due to liftoffD) Both A and C61.What is the relationship between electrical conductivity and electrical resistivity?A) They are directly proportionalB) They are not relatedC) One is the inverse of the otherD) It depends on the test frequency62.When a probe is brought near a conductive but nonmagnetic material, the coils inductive reactance will:A) IncreaseB) DecreaseC) Remain the sameD) Remain the same until the probe touches the material63.The depth of penetration is affected by:A) Magnetic permeabilityB) Electrical resistivityC) Probe drive frequencyD) All of the aboveThe usual objective in radiography is to produce an image showing the highest amount of detail possible. This requires careful control of a number of different variables that can affect image quality.Radiographic sensitivity is a measure of the quality of an image in terms of the smallest detail or discontinuity that may be detected. Radiographic sensitivity is dependant on the combined effects of two independent sets of variables. One set of variables affects the contrast and the other set of variables affects the definition of the image. 通常的目的是在X光产生的图像显示的最高金额可能详细。这需要认真控制多个不同的变量会影响图像质量。射线照相灵敏度是衡量图像质量方面的最小的细节或不连续，可能被发现。放射线敏感性取决于综合影响的独立变量集。一组变量影响的对比和另一组变量影响图像的清晰度There is a tradeoff, however. Generally, as contrast sensitivity increases, the latitude of the radiograph decreases. Radiographic latitude refers to the range of material thickness that can be imaged This means that more areas of different thicknesses will be visible in the image. Therefore, the goal is to balance radiographic contrast and latitude so that there is enough contrast to identify the features of interest but also to make sure the latitude is great enough so that all areas of interest can be inspected with one radiograph. In thick parts with a large range of thicknesses, multiple radiographs will likely be necessary to get the necessary density levels in all areas.In addition to producing high quality radiographs, the radiographer must also be skilled in radiographic interpretation. Interpretation of radiographs takes place in three basic steps: (1) detection, (2) interpretation, and (3) evaluation. All of these steps make use of the radiographers visual acuity. Visual acuity is the ability to resolve a spatial pattern in an image. The ability of an individual to detect discontinuities in radiography is also affected by the lighting condition in the place of viewing, and the experience level for recognizing various features in the image. The following material was developed to help students develop an understanding of the types of defects found in weldments and how they appear in a radiograph.Properly exposing a radiograph is often a trial and error process, as there are many variables that affect the final radiograph. Some of the variables that affect the density of the radiograph include: The spectrum of radiation produced by the x-ray generator. The voltage potential used to generate the x-rays (KeV). The amperage used to generate the x-rays (mA). The exposure time. The distance between the radiation source and the film. The material of the component being radiographed. The thickness of the material that the radiation must travel through. The amount of scattered radiation reaching the film. The film being used. The concentration of the film processing chemicals and the contact time. When a longitudinal wave moves from a slower to a faster material, there is an incident angle that makes the angle of refraction for the wave 90o. This is know as the first critical angle. The first critical angle can be found from Snells law by putting in an angle of 90 for the angle of the refracted ray. At the critical angle of incidence, much of the acoustic energy is in the form of an inhomogeneous compression wave, which travels along the interface and decays exponentially with depth from the interface. This wave is sometimes referred to as a creep wave. Because of their inhomogeneous nature and the fact that they decay rapidly, creep waves are not used as extensively as Rayleigh surface waves in NDT. However, creep waves are sometimes more useful than Rayleigh waves because they suffer less from surface irregularities and coarse material microstructure due to their longer wavelengths.Acoustic signals from the same reflecting surface will have different amplitudes at different distances from the transducer. Distance amplitude correction (DAC) provides a mean