Disciplines

Question 1

AE 1. The most common range of AE is:
a. 10 to 15 kHz
b. 100 to 300 kHz
c. 500 to 750 kHz
d. 1 to 5 MHz

AE

Answer 1

b. 100 to 300 kHz

Question 2

AE 2. Discontinuities that are not readily detectable by AE are:
a. leaks.
b. plastic deformation.
c. growing cracks.
d. rounded inclusions.

Answer 2

d. rounded inclusions.

Question 3

AE 3. The total energy loss of a propagating wave is called:
a. scatter.
b. dispersion.
c. diffraction.
d. attenuation.

Answer 3

d. attenuation.

Question 4

AE 4. The Kaiser effect refers to:
a. velocity changes due to temperature changes.
b. low amplitude emissions from aluminum structures.
c. the behavior where emission from a source will not occur until the previous load is exceeded.
d. emissions from dissimilar material interfaces.

Answer 4

c. the behavior where emission from a source will not occur until the previous load is exceeded.

Question 5

AE 5. The Felicity effect is useful in evaluating:
a. fiber-reinforced plastic components.
b. high-alloy castings.
c. large structural steel members.
d. ceramics.

Answer 5

a. fiber-reinforced plastic components.

Question 6

AE 6. The Kaiser effect is useful in distinguishing:
a. electrical noise from mechanical noise.
b. electrical noise from growing discontinuities.
c. mechanical noise from growing discontinuities.
d. electrical noise from continuous emissions.

Answer 6

c. mechanical noise from growing discontinuities.

Question 7

AE 7. The term “counts” refers to the:
a. number of times a signal crosses a preset threshold.
b. number of events from a source.
c. number of transducers required to perform a test.
d. duration of hold periods.

Answer 7

a. number of times a signal crosses a preset threshold.

Question 8

AE 8. The acoustic emission signal amplitude is related to:
a. the preset threshold.
b. the intensity of the source.
c. the bandpass filters.
d. background noises.

Answer 8

b. the intensity of the source.

Question 9

AE 9. Threshold settings are determined by the:
a. graininess of the material.
b. attenuation of the material.
c. test duration.
d. background noise level.

Answer 9

d. background noise level.

Question 10

AE 10. Background noise can be reduced by:
a. electronic filtering.
b. using flat response amplifiers.
c. using in-line amplifiers.
d. using heavier gauge coaxial cable.

Answer 10

a. electronic filtering.

Question 11

ET 1. Eddy currents are circulating electrical currents induced in conductive materials by:
a. continuous direct current.
b. gamma rays.
c. an alternating magnetic field.
d. a piezoelectric force.

Answer 11

c. an alternating magnetic field.

Question 12

ET 2. The method used to generate eddy currents in a test specimen by means of a coil can most closely be compared with the action of a:
a. transformer.
b. capacitor.
c. storage battery.
d. generator.

Answer 12

a. transformer.

Question 13

ET 3. ET relies on the principle of:
a. magnetostriction.
b. electromagnetic induction.
c. piezoelectric energy conversion.
d. magnetomotive force.

Answer 13

b. electromagnetic induction.

Question 14

ET 4. When the electrical current in an eddy current coil reverses direction, the:
a. direction of the eddy currents in the test part remains the same.
b. eddy currents in the test part will change phase by 45°.
c. direction of the eddy currents in the test part also reverses.
d. eddy currents in the test part will change phase by 90°.

Answer 14

c. direction of the eddy currents in the test part also reverses.

Question 15

ET 5. In order to generate measurable eddy currents in a test specimen, the specimen must be:
a. an electrical conductor.
b. an electrical insulator.
c. a ferromagnetic material.
d. a nonmagnetic material.

Answer 15

a. an electrical conductor.

Question 16

ET 6. The magnetic field generated by eddy currents induced in a test specimen:
a. reinforces the magnetic field that induced the eddy currents.
b. cancels the magnetic field that induced the eddy currents.
c. opposes the magnetic field that induced the eddy currents.
d. has no effect on the magnetic field that induced the eddy currents.

Answer 16

c. opposes the magnetic field that induced the eddy currents.

Question 17

ET 7. In ET, IACS is a recognized abbreviation for:
a. Induced Alternating Current System.
b. Inductively Activated Comparison System.
c. Internal Applied Current System.
d. International Annealed Copper Standard.

Answer 17

d. International Annealed Copper Standard.

Question 18

ET 8. In ET, the specimen is coupled to the test coil by:
a. core coupling.
b. magnetic saturation.
c. the coil’s electromagnetic fields.
d. magnetic domains.

Answer 18

c. the coil’s electromagnetic fields.

Question 19

ET 9. The penetration of eddy currents in a conductive material is decreased when the:
a. test frequency or conductivity of the specimen is decreased.
b. test frequency is decreased or conductivity of the specimen is increased.
c. test frequency, conductivity of the specimen, or permeability of the specimen is increased.
d. permeability of the specimen is decreased.

Answer 19

c. test frequency, conductivity of the specimen, or permeability of the specimen is increased.

Question 20

ET 10. At a fixed test frequency, in which of the following materials will the eddy current penetration be greatest?
a. Aluminum (35% IACS conductivity).
b. Brass (15% IACS conductivity).
c. Copper (95% IACS conductivity).
d. Lead (7% IACS conductivity).

Answer 20

d. Lead (7% IACS conductivity).

Question 21

ET 11. A term used to describe the effect observed due to a change in the coupling between a test specimen and a flat probe coil when the distance of separation between them is varied is:
a. liftoff.
b. fill factor.
c. edge effect.
d. end effect.

Answer 21

a. liftoff.

Question 22

ET 12. When testing with eddy currents, discontinuities will be most easily detected when the eddy currents are:
a. coplanar with the major dimension of the discontinuity.
b. perpendicular to the major plane of the discontinuity.
c. parallel to the major dimension of the discontinuity.
d. 90° out of phase with the current in the coil.

Answer 22

b. perpendicular to the major plane of the discontinuity.

Question 23

ET 13. Which of the following discontinuities is easiest to detect with an electromagnetic test? (Assume that the area of the discontinuity is equal in all four choices listed.)
a. A subsurface crack which lies parallel to the direction of the eddy current.
b. A discontinuity located in the center of a 51 mm (2 in.) diameter bar.
c. A radial crack that extends to the outer surface of a 51 mm (2 in.) diameter bar.
d. A subsurface radial crack located at a depth of 13 mm (0.5 in.) in a 51 mm (2 in.) diameter bar.

Answer 23

c. A radial crack that extends to the outer surface of a 51 mm (2 in.) diameter bar.

Question 24

ET 14. A term used to define the timing relationships involved in alternating current signals is:
a. magnitude.
b. phase.
c. impedance.
d. time-gain correction.

Answer 24

b. phase.

Question 25

ET 15. The impedance of a test coil can be represented by the vector sum of:
a. inductive reactance and resistance.
b. capacitive reactance and resistance.
c. inductive reactance and capacitive reactance.
d. inductive reactance, capacitive reactance, and resistance.

Answer 25

a. inductive reactance and resistance.

Question 26

ET 16. The term “fill factor” applies to:
a. a surface coil.
b. coaxial cable.
c. an encircling coil.
d. the ability to null an eddy current instrument.

Answer 26

c. an encircling coil.

Question 27

ET 17. Which of the following materials would be more likely used as a mounting material for a probe coil?
a. Aluminum.
b. Plastic.
c. Copper.
d. Nonferromagnetic steel.

Answer 27

b. Plastic.

Question 28

ET 18. Which of the following is a commonly used eddy current testing read-out mechanism?
a. Signal generator.
b. Oscilloscope
c. Electronic visual display.
d. Computer screen connected to eddy current system.

Answer 28

a. Signal generator.

Question 29

ET 19. Reference standards used for ET:
a. must contain artificial discontinuities such as notches and drilled holes.
b. must contain natural discontinuities such as cracks and inclusions.
c. must be free of measurable discontinuities, but may contain artificial or natural discontinuities, or may be free of discontinuities, depending on the test system and the type of test being conducted.
d. must be constructed from the same material of the object being inspected.

Answer 29

b. must contain natural discontinuities such as cracks and inclusions.

Question 30

ET 20. Which of the following conditions would be the most difficult to detect when testing a rod using an encircling coil?
a. A short surface crack that has a depth of 10% of the rod diameter.
b. A small inclusion in the center of the rod.
c. A 5% change in diameter.
d. A 10% change in conductivity.

Answer 30

b. A small inclusion in the center of the rod.

Question 31

ET 21. The thickness of nonconductive coatings on a conductive base can be most simply measured by:
a. observing the liftoff effect caused by the coating.
b. testing both sides of the specimen.
c. varying the test frequency over a given range during the test.
d. using a specially shaped encircling coil.

Answer 31

a. observing the liftoff effect caused by the coating.

Question 32

ET 22. Some of the products commonly tested using encircling coils are:
a. rods, tubes, and wire.
b. interior of hollow tubes.
c. sheets and metal foil.
d. square billets and plates.

Answer 32

a. rods, tubes, and wire.

Question 33

ET 23. It is often possible to sort various alloys of a nonmagnetic metal by means of ET when:
a. there is a unique range of permeability values for each alloy.
b. there is a unique range of conductivity values for each alloy.
c. the direction of induced eddy currents varies for each alloy.
d. the magnetic domains for each alloy are different.

Answer 33

b. there is a unique range of conductivity values for each alloy.

Question 34

ET 24. When conducting ET on tubing with a system that includes a frequency discriminating circuit, which of the following variables would be classified as a high-frequency variable?
a. Conductivity changes.
b. Diameter changes.
c. Wall thickness variations.
d. Small discontinuities.

Answer 34

d. Small discontinuities.

Question 35

ET 25. Tubing is generally inspected using:
a. U-shaped coils.
b. gap coils.
c. encircling coils.
d. a sliding probe.

Answer 35

c. encircling coils.

Question 36

ET 26. An out-of-phase condition between current and voltage:
a. can exist in both the primary and secondary windings of an eddy current coil.
b. can exist only in the secondary winding of an eddy current coil.
c. can exist only in the primary winding of an eddy current coil.
d. exists only in the test specimen.

Answer 36

a. can exist in both the primary and secondary windings of an eddy current coil

Question 37

ET 27. For age hardenable aluminum and titanium alloys, changes in hardness are indicated by changes in:
a. retentivity.
b. permeability.
c. conductivity.
d. magnetostriction.

Answer 37

c. conductivity.

Question 38

LT 1. Which of the following systems or components would require the most precaution and special considerations in preparation for a leak test?
a. Piping and pressure vessels.
b. Refrigeration piping.
c. Vacuum chambers.
d. Sintered material components.

Answer 38

d. Sintered material components.

Question 39

LT 2. Pressure change leak testing is dependent on three variables. A change to any of these three will have a direct effect on at least one of the other two variables. These three variables are:
a. pressure, volume, and pumping speed.
b. pressure, volume, and temperature.
c. volume, temperature, and ambient atmospheric pressure.
d. temperature, pumping speed, and fluid viscosity.

Answer 39

b. pressure, volume, and temperature.

Question 40

LT 3. Which of the following is a technique of LT?
a. Static.
b. Gaseous diffusion.
c. Dynamic.
d. Detector probe.

Answer 40

d. Detector probe.

Question 41

LT 4. Which of the following LT techniques can reliably quantify a leak ≤ 10–7 atm cc/sec in a normal industrial environment?
a. Bubble leak testing.
b. Pressure change leak testing.
c. Mass spectrometer leak testing.
d. Liquid penetrant testing.

Answer 41

c. Mass spectrometer leak testing.

Question 42

5. Establishing differential pressure between the test object and the environment is an essential element in which of the following NDT methods?
   a. X-ray diffraction.
   b. Leak testing.
   c. Neutron radiography.
   d. Electromagnetic testing.

Answer 42

b. Leak testing.

Question 43

LT 6. Which of the following best describes the type of leak test used when the interior of the test object is continuously evacuated during the test and a tracer gas is applied to the exterior, while the leak detector is connected to the evacuating system?
a. Static leak test.
b. Helium leak test.
c. Dynamic leak test.
d. Halogen leak test.

Answer 43

c. Dynamic leak test.

Question 44

LT 7. Assuming no significant leakage, if the temperature increases during a pressure drop leak test in a constant volume system, the pressure in the system under test would:
a. increase.
b. remain the same.
c. decrease.
d. first decrease, then increase to its former level.

Answer 44

a. increase.

Question 45

LT 8. If the sensitivity of the halogen leak detector is constant throughout a test, and the pre- and post-test calibrations of the instrument were acceptable, which of the following is true upon completion of the test?
a. No leaks smaller than a certain size have gone undetected.
b. The total leakage rate of the test object is less than a certain amount.
c. The instrument and the test procedure were capable of detecting leakage of a certain size during the test.
d. The instrument and test procedure were only capable of detecting leakage of a certain size upstream of the tracer gas during the test.

Answer 45

c. The instrument and the test procedure were capable of detecting leakage of a certain size during the test.

Question 46

LT 9. All leak detection techniques are dependent upon:
a. barometric pressure.
b. oxygen content of the surrounding air.
c. all of the other gases in the mass spectrometer.
d. establishing a differential pressure across the test boundary.

Answer 46

d. establishing a differential pressure across the test boundary.

Question 47

LT 10. In systems under high vacuum, sensitivity of a pressure change leak test is dependent not only on the pressure change observed, but also on the degree of outgassing. Outgassing is best defined as:
a. the release of gas from materials in a vacuum.
b. directly proportional to the temperature of the gas.
c. the viscosity of the pressurizing gas.
d. the drop in test pressure due to leakage from the vacuum manifold.

Answer 47

a. the release of gas from materials in a vacuum.

Question 48

LT 11. What is the essential information that must be recorded to perform a pressure change leak test?
a. Helium concentration, leak response, background.
b. Barometric pressure, start time, stop time, temperature.
c. Temperature, elapsed time, volume, pressure.
d. Mean free path of helium, fluid viscosity, pressure differential.

Answer 48

c. Temperature, elapsed time, volume, pressure.

Question 49

LT 12. What is the easiest option for increasing sensitivity in a pressure change leak test?
a. Change instrumentation.
b. Turn down the thermostat.
c. Put the test item in an environmental chamber.
d. Increase test time.

Answer 49

d. Increase test time.

Question 50

LT 13. Performing a helium mass spectrometer hood test, what effect would a 50% versus a 100% helium concentration have on the final leak rate of the item being tested?
a. Increase it.
b. Decrease it.
c. No change.
d. Make the leak rate unusable.

Answer 50

b. Decrease it.

Question 51

LT 14. In a pressure change rate of rise test, what test variable is not recorded?
a. Pressure.
b. Volume.
c. Temperature.
d. Elapsed time.

Answer 51

c. Temperature.

Question 52

LT 15. In a helium mass spectrometer leak test using the hood technique, if the inspector has a final calibration 40% greater than the preliminary calibration, what would they do?
a. Nothing.
b. Retest the item.
c. Increase test time.
d. Increase the helium concentration.

Answer 52

b. Retest the item.

Question 53

PT 1. The tendency of a liquid penetrant to enter a discontinuity is primarily related to:
a. the viscosity of the penetrant.
b. capillary action.
c. the chemical inertness of the penetrant.
d. the specific gravity of the penetrant.

Answer 53

b. capillary action.

Question 54

2. PT is a nondestructive test method that can be used for:
   a. locating and evaluating all types of discontinuities in a test specimen.
   b. locating and determining the length, width, and depth of discontinuities in a test specimen.
   c. determining the tensile strength of a test specimen.
   d. locating discontinuities open to the surface.

Answer 54

d. locating discontinuities open to the surface.

Question 55

PT 3. Which of the following processes is best situated to detect shallow discontinuities?
a. Postemulsifiable.
b. Solvent-removable.
c. Aqueous developer.
d. Water-washable.

Answer 55

a. Postemulsifiable.

Question 56

PT 4. The property of a dye used in penetrant materials to emit light in the range of wavelengths different from the wavelength of visible light that excites the emission is called:
a. emissivity.
b. irradiation.
c. spectrum blocking.
d. fluorescence.

Answer 56

d. fluorescence.

Question 57

PT 5. When using a fluorescent, postemulsifier penetrant, the length of time the emulsifier is allowed to remain on the part is critical for detecting shallow discontinuities. The optimum length of time should be:
a. 10 seconds.
b. 5 seconds.
c. 2 to 3 minutes.
d. determined by experimentation.

Answer 57

d. determined by experimentation.

Question 58

PT 6. A red penetrant indication against white background is most likely to be seen when:
a. dry developers are used.
b. visible dye penetrants are used.
c. fluorescent postemulsified penetrants are used.
d. ultraviolet light is used with visible dye penetrants.

Answer 58

b. visible dye penetrants are used.

Question 59

PT 7. The most widely accepted technique for removing excess water-washable penetrant from the surface of a test specimen is by:
a. using a wet rag.
b. using a coarse water spray rinse.
c. washing the part directly under water running from a tap.
d. immersing the part in water.

Answer 59

b. using a coarse water spray rinse.

Question 60

PT 8. Which of the following PT systems is generally considered the least sensitive?
a. Water-washable; visible dye.
b. Solvent-removable; visible dye.
c. Water-washable; fluorescent dye.
d. Postemulsified; visible dye.

Answer 60

a. Water-washable; visible dye.

Question 61

PT 9. When performing PT using solvent-removable visible dye penetrant, there are several ways to remove excess penetrant from the surface of the part. Which of the techniques listed below is generally regarded as most suitable for giving accurate test results?
a. Squirting solvent over the surface with no more than 69 kPa (10 psi) pressure.
b. Wiping with a solvent-soaked cloth, then wiping with a dry cloth.
c. Wiping with a solvent-dampened cloth, then wiping with dry cloths.
d. Wiping with dry cloths, then wiping with a solvent-dampened cloth, and finally wiping with a dry cloth.

Answer 61

d. Wiping with dry cloths, then wiping with a solvent-dampened cloth, and finally wiping with a dry cloth.

Question 62

PT 10. A problem with retesting a specimen that has been previously tested using PT is that the:
a. penetrant residue left in discontinuities may not readily dissolve, and the retest may be misleading.
b. penetrant may form beads on the surface.
c. penetrant will lose a great deal of its color brilliance.
d. added penetrant will intensify the penetrant residue, making indications larger than normal.

Answer 62

a. penetrant residue left in discontinuities may not readily dissolve, and the retest may be misleading.

Question 63

PT 11. A commonly used method of checking the overall performance of a liquid penetrant material system is to:
a. determine the viscosity of the penetrant.
b. measure the wettability of the penetrant.
c. compare two sections of artificially cracked specimens.
d. check the penetrant contaminant levels.

Answer 63

c. compare two sections of artificially cracked specimens.

Question 64

PT 12. The function of emulsifier in the postemulsified penetrant process is to:
a. influence the rate of penetration into deep, tight cracks.
b. react with the surface penetrant to make the penetrant water washable.
c. add fluorescent dye or pigment to the penetrant.
d. emulsify surface oils and greases to facilitate their removal.

Answer 64

b. react with the surface penetrant to make the penetrant water washable.

Question 65

PT 13. Which of the following statements most applies to developers used during PT?
a. Developers are normally highly fluorescent.
b. Some developers furnish a fluctuating background during inspection.
c. Developers absorb or blot the penetrant that remains in discontinuities after the excess penetrant has been removed.
d. Nonaqueous developers are better suited for very humid environments.

Answer 65

c. Developers absorb or blot the penetrant that remains in discontinuities after the excess penetrant has been removed.

Question 66

PT 14. The penetrant indication for a cold shut on the surface of a casting will normally be:
a. a dotted line.
b. a large bulbous indication.
c. a smooth continuous line.
d. undetectable since cold shuts are closed over on the surface.

Answer 66

c. a smooth continuous line.

Question 67

PT 15. A crack-type discontinuity will generally appear as:
a. a rounded indication.
b. a continuous line, either straight or jagged.
c. a broad, fuzzy indication.
d. random round or elongated holes.

Answer 67

b. a continuous line, either straight or jagged.

Question 68

16. In PT, scattered round indications on the surface of a part could be indicative of:
    a. fatigue cracks.
    b. porosity.
    c. weld laps.
    d. hot tears.

Answer 68

b. porosity.

Question 69

PT 17. Which of the following are typical nonrelevant indications found in PT?
a. Indications due to part geometry or part design configurations.
b. Nonmagnetic indications.
c. Indications due to contact with another test object.
d. Indications on low-stressed areas of the part.

Answer 69

a. Indications due to part geometry or part design configurations.

Question 70

PT 18. Which of the statements below best states the effects of sandblasting for the cleaning of surfaces to be tested with PT?
a. Surface discontinuities may be closed.
b. Oil contaminants might be sealed in the discontinuities.
c. The sand used in the sandblasting operation may be forced into the discontinuity.
d. The sandblasting operation may introduce discontinuities into the part.

Answer 70

a. Surface discontinuities may be closed.

Question 71

PT 19. The penetrant indication of a forging lap will normally be a:
a. round or nearly round indication.
b. cluster of indications.
c. thin continuous line.
d. dotted line.

Answer 71

c. thin continuous line.

Question 72

PT 20. Aluminum alloy test specimens that have been tested with PT should be thoroughly cleaned after testing because:
a. acid in the penetrant may cause severe corrosion.
b. the oily residue from the test will severely inhibit the application of paint on aluminum alloys.
c. a chemical reaction between the penetrant and aluminum could cause a fire.
d. the alkalines in wet developers and most emulsifiers could cause surface pitting, particularly in moist atmospheres.

Answer 72

d. the alkalines in wet developers and most emulsifiers could cause surface pitting, particularly in moist atmospheres.

Question 73

21. Which of the following is a discontinuity that might be found in rolled bar stock?
    a. Blow holes.
    b. Shrinkage laps.
    c. Stringers or seams.
    d. Insufficient penetration.

Answer 73

c. Stringers or seams.

Question 74

PT 22. Anodized surfaces are usually considered poor candidates for high-sensitivity PT because the anodizing process produces a conversion layer that:
a. is extremely smooth and slick.
b. has a multitude of extremely small pores.
c. may have alkaline residue that “quenches” the penetrant.
d. cannot be cleaned by ordinary processes.

Answer 74

b. has a multitude of extremely small pores.

Question 75

PT 23. Which of the following PT techniques is best suited for performing inspections without a source of electricity?
a. Water-washable fluorescent penetrant.
b. Postemulsified fluorescent penetrant.
c. Visible dye penetrant.
d. Hydrophilic fluorescent penetrant.

Answer 75

c. Visible dye penetrant.

Question 76

PT 24. Which of the following statements is true concerning PT of welds with rough surfaces?
a. The postemulsified process offers advantages over the water-washable process.
b. If the solvent removal process is used, the best developer would be an aqueous suspension.
c. Welds with rough surfaces cannot be successfully tested by any PT technique.
d. Welds with rough surfaces may need to be ground smooth prior to PT.

Answer 76

d. Welds with rough surfaces may need to be ground smooth prior to PT.

Question 77

PT 25. A penetrant must:
a. change viscosity in order to spread over the surface of the part.
b. spread easily over the surface of the material.
c. have a low flash point.
d. be able to change color in order to fluoresce.

Answer 77

b. spread easily over the surface of the material.

Question 78

26. Which of the following discontinuities could be classified as an in-service related discontinuity?
    a. Grinding cracks.
    b. Porosity.
    c. Stress-corrosion crack.
    d. Cold lap.

Answer 78

c. Stress-corrosion crack.

Question 79

PT 27. Penetrant materials are tested and qualified to what specification?
a. AMS 2642
b. AMS 2644
c. AMS 2646
d. AMS 2648

Answer 79

b. AMS 2644

Question 80

PT 28. Which of the following penetrants is able to be removed with water?
a. Method A penetrant.
b. Method B penetrant.
c. Method C penetrant.
d. Method D penetrant.

Answer 80

a. Method A penetrant

Question 81

PT 29. Fluorescent dye penetrant is typically which color?
a. Red.
b. Yellow-green.
c. Orange.
d. Blue.

Answer 81

b. Yellow-green.

Question 82

MFL 1. In MFL inspection for discontinuities using an active field, the part being inspected should be magnetized:
a. beyond saturation.
b. to saturation or near saturation.
c. well below saturation.
d. near the point of maximum permeability.

Answer 82

a. beyond saturation.

Question 83

MFL 2. An advantage that MFL has in comparison with ET is that MFL is:
a. less sensitive to interferences caused by surface roughness.
b. useful on products at temperatures above the curie point.
c. useful on austenitic steels.
d. easier to use on ferromagnetic materials.

Answer 83

d. easier to use on ferromagnetic materials.

Question 84

MFL 3. What type of discontinuity would not typically be indicated by MFL techniques?
a. Laps.
b. Pitting with cracking.
c. Deep-surface discontinuities.
d. Longitudinal seams.

Answer 84

c. Deep-surface discontinuities.

Question 85

MFL 4. The strength of the magnetic field in the interior of a coil is determined by the:
a. number of turns in the coil only.
b. strength of applied current only.
c. number of turns in the coil and the strength of the applied current.
d. direction of applied current in the coil.

Answer 85

c. number of turns in the coil and the strength of the applied current.

Question 86

MFL 5. The current used for magnetization when performing MFL must be a:
a. steady nonfluctuating current.
b. current that reverses direction at an inconsistent rate.
c. current that fluctuates on and off at a consistent rate.
d. current that varies based on the thickness of the material.

Answer 86

a. steady nonfluctuating current.

Question 87

MFL 6. As a general rule, hard (high-strength) ferromagnetic materials have:
a. high coercive force and are easily demagnetized.
b. high coercive force and are not easily demagnetized.
c. low coercive force and are easily demagnetized.
d. low coercive force and are not easily demagnetized.

Answer 87

b. high coercive force and are not easily demagnetized.

Question 88

MFL 7. In MFL, the greatest tube wall thickness for which maximum sensitivity can be maintained is:
a. 0.08 mm (0.003 in.)
b. 0.8 mm (0.03 in.)
c. 8 mm (0.318 in.)
d. 76 mm (3 in.)

Answer 88

c. 8 mm (0.318 in.)

Question 89

MFL 8. In the examination of aboveground storage tanks where the flux sensor is on the top surface:
a. only top surface discontinuities are detected.
b. only bottom surface discontinuities are detected.
c. both top and bottom surface discontinuities can be detected and can generally be distinguished from each other.
d. both top and bottom surface discontinuities can be detected but generally cannot be distinguished from each other.

Answer 89

d. both top and bottom surface discontinuities can be detected but generally cannot be distinguished from each other.

Question 90

MFL 9. Materials that are weakly repelled magnetically are called:
a. diamagnetic.
b. nonmagnetic.
c. paramagnetic.
d. ferromagnetic.

Answer 90

a. diamagnetic.

Question 91

MFL 10. A break in the magnetic uniformity of a part that is called a magnetic discontinuity is related to a sudden change in:
a. resistivity.
b. inductance.
c. permeability.
d. capacitance.

Answer 91

c. permeability.

Question 92

MFL 11. A hysteresis curve describes the relation between:
a. magnetizing force and flux density.
b. magnetizing force and applied current.
c. strength of magnetism and alignment of domains within material.
d. magnetic flux density and the current generated.

Answer 92

a. magnetizing force and flux density.

Question 93

MFL 12. When inspecting wire rope, a magnetic flux loop is used to monitor:
a. broken external wires.
b. broken internal wires.
c. changes in inspection speed.
d. reductions in cross-sectional area.

Answer 93

d. reductions in cross-sectional area.

Question 94

MFL 13. A hall effect probe measures:
a. permeability.
b. conductivity.
c. flux density perpendicular to the probe surface.
d. tangential field strength.

Answer 94

c. flux density perpendicular to the probe surface.

Question 95

MFL 14. The direction of magnetic lines of force are generally considered to be _____ from the direction of current flow.
a. 45°
b. 90°
c. 180°
d. 270°

Answer 95

b. 90°

Question 96

MFL 15. If the sensor bounces along the surface of aboveground storage tanks, it may:
a. make it difficult to estimate the severity of an indication.
b. generate noise in the signal.
c. decrease the speed of the inspection.
d. distort the magnetizing system.

Answer 96

b. generate noise in the signal.

Question 97

MFL 16. In an MFL examination of aboveground storage tanks, the factor(s) that must be considered when interpreting an indication is/are:
a. signal amplitude only.
b. signal width only.
c. visual and ultrasonic evaluation.
d. signal amplitude and width.

Answer 97

c. visual and ultrasonic evaluation.

Question 98

MFL 17. In the application of pipe body inspection, longitudinal magnetization is best for detection of:
a. longitudinal discontinuities.
b. transverse discontinuities.
c. internal surface discontinuities.
d. subsurface discontinuities.

Answer 98

b. transverse discontinuities.

Question 99

MFL 18. Residual magnetization is the:
a. magnetizing force remaining after flux density has decreased.
b. residual magnetizing force beyond the curie point.
c. flux density after removal of magnetizing force.
d. flux density beyond the level of saturation.

Answer 99

c. flux density after removal of magnetizing force.

Question 100

MT 1. Which of the following materials is considered nonferrous?
a. Copper alloys.
b. High alloy steels.
c. Tool steels.
d. Ferritic stainless steels.

Answer 100

a. Copper alloys.

Question 101

MT 2. Materials that are strongly attracted to a magnet are called:
a. magnetized.
b. nonmagnetic.
c. ferromagnetic.
d. magnetic.

Answer 101

c. ferromagnetic.

Question 102

MT 3. Magnetic lines of force (magnetic fields) are oriented in what direction in relation to the direction of the magnetizing current?
a. Parallel.
b. At right angles.
c. At a 45° angle.
d. At random angles.

Answer 102

b. At right angles.

Question 103

MT 4. “Magnetizing flux” is a term that relates to:
a. the direction of current flow in an electromagnet.
b. the manner by which magnetism flows through space.
c. the lines of force associated with a magnetic field.
d. permanent magnets only.

Answer 103

c. the lines of force associated with a magnetic field.

Question 104

MT 5. Subjecting a part to a magnetic field that is constantly reversing in polarity and gradually diminishing in strength accomplishes which of the following?
a. Demagnetizes the part.
b. Magnetizes the part.
c. Increases the residual magnetism.
d. Locates deep-lying discontinuities.

Answer 104

a. Demagnetizes the part.

Question 105

MT 6. Circular magnetization is useful in the detection of:
a. circumferential cracks.
b. longitudinal cracks.
c. cracks in cylindrical parts at right angles to the long axis of the part.
d. deep-lying discontinuities.

Answer 105

b. longitudinal cracks.

Question 106

MT 7. In which magnetizing method is the current passed directly through the part, thereby setting up a magnetic field at right angles to the current flow?
a. Longitudinal magnetization.
b. Coil magnetization.
c. Central conductor magnetization.
d. Circular magnetization.

Answer 106

d. Circular magnetization.

Question 107

MT 8. Which of the following is a major disadvantage of using prods?
a. The magnetic field may be applied in the wrong direction.
b. The inspection surface may be arc burned.
c. Magnetic saturation may occur.
d. Control of the amperage

Answer 107

b. The inspection surface may be arc burned.

Question 108

MT 9. Inspecting a part by applying the wet magnetic particle suspension while the current is flowing is called the:
a. continuous method.
b. dry method.
c. residual method.
d. demagnetization method.

Answer 108

a. continuous method.

Question 109

MT 10. How is the inside diameter of a cylinder best magnetized?
a. By a head shot.
b. By using prods at either end.
c. With a central conductor placed between contact heads.
d. With the cylinder placed crosswise in a solenoid.

Answer 109

c. With a central conductor placed between contact heads.

Question 110

MT 11. The amount of amperage used for MT using prods is based on the distance between the prods and the:
a. thickness of the part.
b. length of the prods.
c. diameter of the prods.
d. total length of the part.

Answer 110

a. thickness of the part.

Question 111

MT 12. Demagnetization of a part is usually necessary if the part is:
a. made of stainless steel.
b. is a nonferromagnetic steel.
c. high-carbon steel to be welded after inspection.
d. to be hardened by heat treatment after inspection.

Answer 111

d. to be hardened by heat treatment after inspection.

Question 112

MT 13. Which of the following is an advantage of the dry technique over the wet technique?
a. It is more sensitive for detecting fine surface cracks.
b. It is more capable of providing full surface coverage on irregularly shaped parts.
c. It is easier to use for field inspection with portable equipment.
d. It is faster when testing many small parts.

Answer 112

c. It is easier to use for field inspection with portable equipment.

Question 113

MT 14. Fluorescent magnetic particles are used in preference over visible magnetic particles:
a. when parts are big and bulky.
b. when working in the field.
c. if parts are for railroad applications.
d. to increase the speed and reliability of detecting very small discontinuities.

Answer 113

d. to increase the speed and reliability of detecting very small discontinuities.

Question 114

MT 15. What causes a leakage field in a steel bar?
a. Paint on the bar surface.
b. A longitudinal crack.
c. Reversal of the magnetic field.
d. Hysteresis.

Answer 114

b. A longitudinal crack.

Question 115

16. MT techniques are recognized as superior to liquid penetrant testing techniques when the:
    a. surfaces of the test object are corroded.
    b. surface is anodized.
    c. parts are painted.
    d. part is made from austenitic steel.

Answer 115

c. parts are painted.

Question 116

MT 17. When using direct current, an indication is detected. What is the next logical step to determine if the indication results from a surface or subsurface condition?
a. Reinspect using the surge method.
b. Demagnetize and apply powder.
c. Reinspect at higher amperage.
d. Reinspect using alternating current.

Answer 116

d. Reinspect using alternating current.

Question 117

MT 18. A requirement to use MT on a part should also include:
a. a fabrication and service manual.
b. a statement on the drawing that requires MT.
c. the procedure to be used and acceptance criteria.
d. the method of test and service conditions.

Answer 117

c. the procedure to be used and acceptance criteria.

Question 118

MT 19. The reverse magnetizing force necessary to remove a residual magnetic field from a test piece after it has been magnetically saturated is called:
a. coercive force.
b. demagnetizing flux.
c. reverse saturation.
d. direct force.

Answer 118

a. coercive force.

Question 119

MT 20. The best type of magnetizing current for inspection of fatigue cracks is:
a. direct current.
b. alternating current.
c. half-wave rectified alternating current.
d. full-wave current.

Answer 119

b. alternating current.

Question 120

MT 21. A star-shaped indication is seen on the cover pass of a weld. What type of discontinuity is indicated?
a. Crater crack.
b. Cooling crack.
c. Slag inclusion.
d. Arc burn.

Answer 120

a. Crater crack.

Question 121

MT 22. For maximum sensitivity in MT of rough welds:
a. the weld should be wire brushed to remove slag and scale.
b. standard test weldments should be used for comparison.
c. the weld bead should be coated with lacquer.
d. the weld bead should be ground to remove surface irregularities.

Answer 121

d. the weld bead should be ground to remove surface irregularities.

Question 122

MT 23. Ferromagnetic materials are made up of small, polarized regions known as:
a. photons.
b. quarks.
c. electrons.
d. domains.

Answer 122

d. domains.

Question 123

MT 24. The reapplication of magnetic particle suspension after current has already been applied to a part is known as the:
a. residual method.
b. continuous method.
c. magnetization method.
d. demagnetization method.

Answer 123

a. residual method.

Question 124

MT 25. Subsurface indications will have the appearance of:
a. well-defined lines.
b. fuzzy-looking lines.
c. bright, solid lines.
d. intermittent lines.

Answer 124

b. fuzzy-looking lines.

Question 125

MT 26. The areas on a magnetized part from which the magnetic field is leaving or returning into the part are called:
a. defects.
b. salient points.
c. magnetic poles.
d. nodes.

Answer 125

c. magnetic poles.

Question 126

MT 27. The strength of a magnetic field induced in a part is often referred to as:
a. retentivity.
b. current density.
c. voltage.
d. flux density.

Answer 126

d. flux density.

Question 127

NRT 1. The highest intensity sources of thermal neutrons are:
a. Cf-252 isotopes.
b. accelerators.
c. nuclear fission reactors.
d. cosmic radiation.

Answer 127

c. nuclear fission reactors.

Question 128

NRT 2. Neutrons for fast-neutron radiography are obtainable from:
a. accelerators.
b. Co-60 or Ir-192.
c. moderated neutrons from reactors.
d. X-ray machines.

Answer 128

a. accelerators.

Question 129

NRT 3. A radioactive source used for NR is:
a. Cf-252.
b. Pu-239.
c. Co-60.
d. Cs-137.

Answer 129

a. Cf-252.

Question 130

NRT 4. The energy of the neutron is expressed in which of the following units of measurement?
a. Curies (becquerels).
b. Röntgen (coulombs per kilogram).
c. Rem (sieverts).
d. Electronvolts.

Answer 130

d. Electronvolts.

Question 131

NRT 5. A normally desirable feature of a thermal neutron beam for NR is:
a. background gamma radiation intensity.
b. relatively low fast-neutron intensity.
c. low angular divergence.
d. relatively high thermal neutron intensity.

Answer 131

b. relatively low fast-neutron intensity.

Question 132

NRT 6. A material that slows down neutrons is called:
a. a moderator.
b. an accumulator.
c. a limitor.
d. a collimator.

Answer 132

a. a moderator.

Question 133

NRT 7. The primary radiation mechanism for darkening radiographic film when the direct NR process is used with gadolinium screens is:
a. alpha particles.
b. electrons.
c. gamma rays.
d. light emission.

Answer 133

b. electrons.

Question 134

NRT 8. NR using the transfer method requires that the imaging screen must:
a. be placed behind the film.
b. be placed in front of the film.
c. be very thin.
d. become radioactive.

Answer 134

d. become radioactive.

Question 135

9. Which of the following NR converter foils cannot be used for transfer or indirect radiography?
   a. Dysprosium.
   b. Indium.
   c. Gadolinium.
   d. Gold.

Answer 135

c. Gadolinium.

Question 136

10. The most suitable films for producing neutron radiographs are:
    a. industrial X-ray films.
    b. red-sensitive films.
    c. instant-type films.
    d. emulsions that contain no silver halides.

Answer 136

a. industrial X-ray films.

Question 137

11. Materials that are exposed to thermal neutron beams:
    a. must not be handled for at least 3 min after exposure has ceased.
    b. must be stored in a lead-lined room.
    c. should be monitored by means of a neutron counter.
    d. may be radioactive after exposure to neutrons has ceased.

Answer 137

d. may be radioactive after exposure to neutrons has ceased.

Question 138

12. Lead is:
    a. a good neutron shield.
    b. corroded by neutron exposures.
    c. a relatively poor neutron absorber.
    d. an efficient conversion screen.

Answer 138

c. a relatively poor neutron absorber.

Question 139

13. If 2 mm (0.08 in.) of plastic attenuates a thermal neutron beam by a factor of 2, then 20 mm (0.8 in.) will attenuate it by approximately a factor of:
    a. 10.
    b. 20.
    c. 200.
    d. 1000.

Answer 139

d. 1000.

Question 140

14. Materials in common usage for moderation of fast-neutron sources include:
    a. aluminum, magnesium, and tin.
    b. water, plastic, paraffin, and graphite.
    c. neon, argon, and xenon.
    d. tungsten, cesium, antimony, and columbium.

Answer 140

b. water, plastic, paraffin, and graphite.

Question 141

15. The main reason for using NR in place of X-radiography is:
    a. a lower cost.
    b. higher resolution.
    c. the ability to image objects and materials not possible with X-rays.
    d. it is a simpler radiographic procedure when required than X-radiography.

Answer 141

c. the ability to image objects and materials not possible with X-rays.

Question 142

16. A photographic record produced by the passage of neutrons through a specimen onto a film is called:
    a. a fluoroscopic image.
    b. an isotopic reproduction.
    c. a radiograph.
    d. a track-etch photograph.

Answer 142

c. a radiograph.

Question 143

17. Many of the absorption differences between neutrons and X-rays indicate that the two techniques:
    a. cause radiation problems.
    b. complement each other.
    c. can be used interchangeably.
    d. can both be used to image hydrogenous materials equally well.

Answer 143

b. complement each other

Question 144

18. The penetrating ability of a thermal neutron beam is governed by:
    a. attenuating characteristics of the material being penetrated.
    b. exposure time.
    c. source-to-film distance.
    d. thickness of the converter screen.

Answer 144

a. attenuating characteristics of the material being penetrated.

Question 145

19. The transfer exposure method is used because:
    a. it is not influenced by gamma radiation in the primary beam.
    b. it produces greater radiographic sensitivity than direct exposure using gadolinium.
    c. it is faster than the direct exposure method.
    d. the screens used in this method emit only internal conversion electrons of about 70 keV.

Answer 145

a. it is not influenced by gamma radiation in the primary beam.

Question 146

20. Higher resolution can be achieved in direct NR by:
    a. placing a lead intensifying screen between a gadolinium screen and the film.
    b. increasing the length-to-diameter ratio of the collimation system.
    c. increasing the exposure time.
    d. increasing the distance between the object and the film cassette.

Answer 146

b. increasing the length-to-diameter ratio of the collimation system.

Question 147

21. The primary advantage of using a Cf-252 source for NR is its:
    a. portability.
    b. low cost per unit neutron flux compared to other neutron radiographic sources.
    c. high resolution.
    d. long useful life.

Answer 147

a. portability.

Question 148

22. Quality of the results from a neutron radiographic exposure is best determined by:
    a. reference standards.
    b. image quality indicators.
    c. neutron flux measurement.
    d. densitometer readings.

Answer 148

b. image quality indicators.

Question 149

23. The radiographic image of apparent discontinuities in the imaging screens can be separated from actual discontinuities in a part being radiographed by:
    a. comparing a neutron radiograph of the parts to a blank neutron radiograph of the same imaging screen with no parts in place.
    b. producing a photographic copy of the original neutron radiograph using X-ray duplicating film.
    c. increasing the exposure time of the radiograph.
    d. decreasing the temperature of the developer solution.

Answer 149

a. comparing a neutron radiograph of the parts to a blank neutron radiograph of the same imaging screen with no parts in place.

Question 150

24. For inspection of radioactive objects or those that emit gamma radiation when bombarded with neutrons, a preferable detection technique is the:
    a. direct exposure technique.
    b. transfer technique.
    c. isotopic reproduction technique.
    d. electrostatic-belt generator technique.

Answer 150

b. transfer technique.

Question 151

25. NR is an excellent tool for determining:
    a. the coating thickness of aluminum oxide on anodized aluminum.
    b. the size of voids in thick steel castings.
    c. the integrity of thin plastic material within a steel housing.
    d. tungsten inclusions in gas tungsten arc welding welds.

Answer 151

c. the integrity of thin plastic material within a steel housing.

Question 152

26. NR extends radiographic capability for detecting cracks in small cylinders of:
    a. aluminum.
    b. iron.
    c. magnesium.
    d. plutonium.

Answer 152

d. plutonium.

Question 153

27. Which of the following is a preferred application of NR?
    a. Detection of tungsten inclusions in titanium ingots.
    b. Detecting the presence of water in the cells of stainless steel honeycomb.
    c. Detecting slag inclusions in structural steel welds.
    d. Determination of the depth of seating of a projectile in a metallic case.

Answer 153

b. Detecting the presence of water in the cells of stainless steel honeycomb.

Question 154

28. Common sources of neutrons for NR are:
    a. electron linear accelerators.
    b. isotopes of cobalt (e.g., Co-60).
    c. nuclear reactors.
    d. betatrons.

Answer 154

c. nuclear reactors.

Question 155

1. The penetrating ability of an X-ray beam is governed by:
   a. kilovoltage or wavelength (energy).
   b. time.
   c. milliamperage.
   d. source-to-film distance.

Answer 155

a. kilovoltage or wavelength (energy).

Question 156

2. Two X-ray machines operating at the same nominal kilovoltage and milliamperage settings:
   a. will produce the same intensities and energies of radiation.
   b. will produce the same intensities but may produce different energies of radiation.
   c. will produce the same energies but may produce different intensities of radiation.
   d. may give not only different intensities but also different energies of radiation.

Answer 156

d. may give not only different intensities but also different energies of radiation.

Question 157

3. Short wavelength electromagnetic radiation produced during the disintegration of nuclei of radioactive substances is called:
   a. X-radiation.
   b. gamma radiation.
   c. scatter radiation.
   d. beta radiation.

Answer 157

b. gamma radiation.

Question 158

4. Almost all gamma radiography is performed with:
   a. natural isotopes.
   b. artificially produced isotopes.
   c. radium.
   d. Co-60.

Answer 158

b. artificially produced isotopes.

Question 159

5. The energy of gamma rays is expressed by which of the following units of measurement?
   a. Curie (gigabecquerel).
   b. Röntgen (coulomb per kilogram).
   c. Half-life.
   d. Kiloelectronvolts (keV) or megaelectronvolts (MeV).

Answer 159

d. Kiloelectronvolts (keV) or megaelectronvolts (MeV).

Question 160

6. Of the following, the source providing the most penetrating radiation is:
   a. Co-60.
   b. 220 kVp X-ray tube.
   c. 15 MeV betatron.
   d. electrons from Ir-192.

Answer 160

c. 15 MeV betatron.

Question 161

7. The difference between the densities of two areas of a radiograph is called:
   a. radiographic contrast.
   b. subject contrast.
   c. film contrast.
   d. definition.

Answer 161

a. radiographic contrast.

Question 162

8. The fact that gases, when bombarded by radiation, ionize and become electrical conductors makes them useful in:
   a. X-ray transformers.
   b. fluoroscopes.
   c. masks.
   d. radiation detection equipment.

Answer 162

d. radiation detection equipment.

Question 163

9. The reason exposure time must be increased by a factor of four when the source-to-film distance is doubled is that the:
   a. intensity of radiation decreases at an exponential rate when the source-to-film distance is increased.
   b. energy of radiation is inversely proportional to the square root of the distance from the source to the film.
   c. intensity of radiation is inversely proportional to the square of the distance from the source to the film.
   d. scattered radiation effect is greater as the source-to-film distance increases.

Answer 163

c. intensity of radiation is inversely proportional to the square of the distance from the source to the film.

Question 164

10. The most important factor in X-ray absorption of a specimen is:
    a. the thickness of the specimen.
    b. the density of the specimen.
    c. Young’s modulus of the material.
    d. the atomic number of the material.

Answer 164

d. the atomic number of the material.

Question 165

11. The maximum permissible dose per calendar year is 5 rem (0.05 Sv) for:
    a. extremities.
    b. skin.
    c. whole body (total effective dose equivalent).
    d. a fetus from occupational exposure of a declared pregnant woman.

Answer 165

c. whole body (total effective dose equivalent).

Question 166

12. Exposure to small doses of X-rays or gamma rays:
    a. has a cumulative effect that must be considered when monitoring for maximum permissible dose.
    b. is beneficial because it serves to build an immunity in humans to radiation poisoning.
    c. will have no effect on human beings.
    d. will have only a short-term effect on human tissues.

Answer 166

a. has a cumulative effect that must be considered when monitoring for maximum permissible dose.

Question 167

13. Which of the following technique variables is most commonly used to adjust subject contrast?
    a. Source-to-film distance.
    b. Milliamperage.
    c. Kilovoltage.
    d. Focal spot size.

Answer 167

c. Kilovoltage.

Question 168

14. A basic difference between a radiograph and a fluoroscopic image is:
    a. the fluoroscopic image is more sensitive.
    b. the fluoroscopic image is positive whereas the radiographic image is negative.
    c. the fluoroscopic image is brighter.
    d. there is no basic difference between the two.

Answer 168

b. the fluoroscopic image is positive whereas the radiographic image is negative.

Question 169

15. Thin sheets of lead foil in intimate contact with X-ray film during exposure increase film density because they:
    a. fluoresce and emit visible light, which helps expose the film.
    b. absorb the scattered radiation.
    c. prevent backscattered radiation from fogging the film.
    d. emit electrons when exposed to X- and gamma radiation, which helps to darken the film.

Answer 169

d. emit electrons when exposed to X- and gamma radiation, which helps to darken the film.

Question 170

16. When viewing a radiograph, an image of the back of the cassette superimposed on the image of the specimen is noted. This is most likely due to:
    a. undercut.
    b. overexposure.
    c. X-ray intensity being too high.
    d. backscatter radiation.

Answer 170

d. backscatter radiation.

Question 171

17. An image quality indicator (IQI) is used to measure the:
    a. size of discontinuities in a part.
    b. density of the film.
    c. quality of the radiographic technique.
    d. amount of radiation that penetrates the test object.

Answer 171

c. quality of the radiographic technique.

Question 172

18. In film radiography, IQIs are usually placed:
    a. between the intensifying screen and the film.
    b. on the source side of the test object.
    c. on the film side of the test object.
    d. between the operator and the radiation source.

Answer 172

b. on the source side of the test object.

Question 173

19. At voltages above 400 kV, the use of lead to provide protection may present serious structural problems. If this should be the case, which of the following materials would most likely be used as a substitute?
    a. Concrete.
    b. Aluminum.
    c. Steel.
    d. Boron.

Answer 173

a. Concrete.

Question 174

20. A distinctive characteristic of megavolt radiography is that it:
    a. results in comparatively high subject contrast.
    b. results in comparatively high radiographic contrast.
    c. is applicable to comparatively thick or highly absorbing specimens.
    d. is utilized for stainless steels only.

Answer 174

c. is applicable to comparatively thick or highly absorbing specimens.

Question 175

21. Given the radiographic equivalency factors of 1.4 for InconelTM and 1.0 for 304 stainless steel, what is the approximate equivalent thickness of InconelTM to produce the same exposure as a 3.8 mm (0.15 in.) thickness of 304 stainless steel?
    a. 3 mm (0.11 in.)
    b. 9 mm (0.35 in.)
    c. 18 mm (0.7 in.)
    d. 36 mm (1.4 in.)

Answer 175

a. 3 mm (0.11 in.)

Question 176

22. The fact that each solid crystalline substance produces its own characteristic X-ray pattern is the basis for:
    a. xeroradiography.
    b. X-ray diffraction testing.
    c. fluoroscopic testing.
    d. polymorphic testing.

Answer 176

b. X-ray diffraction testing.

Question 177

23. When inspecting a light metal casting by fluoroscopy, which of the following discontinuities would most likely be detected?
    a. Copper shrinkage.
    b. Microshrinkage.
    c. Shrinkage.
    d. Fine cracks.

Answer 177

c. Shrinkage.

Question 178

24. For testing a 25 mm (1 in.) steel plate 305 mm (12 in.) square for laminar discontinuities, which of the following would be most effective?
    a. 3.7 TBq (100 Ci) of Ir-192.
    b. 925 GBq (25 Ci) of Co-60.
    c. 250 kVp X-ray machine.
    d. An ultrasonic device.

Answer 178

d. An ultrasonic device.

Question 179

25. A critical weld was made with a double vee-groove. Among those listed, which radiographic technique would provide coverage with the greatest probability for detecting the most serious discontinuities?
    a. A single exposure centered on the weld and perpendicular to the principal surface of the plate.
    b. Two exposures aligned with the vee-groove, focus ±30° off perpendicular.
    c. Two exposures, perpendicular to the plate, offset by the width of the weld bead.
    d. A single exposure centered on the weld with two films aligned ±30° off perpendicular to the principal surface of the plate.

Answer 179

b. Two exposures aligned with the vee-groove, focus ±30° off perpendicular.

Question 180

26. A fuse assembly is radiographed so that measurements can be made on the film to determine a minimum internal clearance dimension. What should be factored into the dimension taken from the film?
    a. Projection magnification.
    b. Film latitude.
    c. Slope of the characteristic curve.
    d. IQI alignment.

Answer 180

a. Projection magnification.

Question 181

27. Miniature electronic components are to be radiographically inspected to reveal broken copper wire leads of 0.008 in. (0.2 mm) diameter. Which of the following IQIs would be most effective to use in establishing a reliable technique?
    a. A series of steel plaque-type IQIs ranging in thickness from 0.1 mm (0.005 in.) to 0.4 mm (0.015 in.), containing 1T, 2T, and 4T holes.
    b. A plastic block with the radiographic thickness equivalent of the test objects, containing precision-drilled holes ranging from 0.1 mm (0.005 in.) to 0.4 mm (0.015 in.) diameter.
    c. A plastic block with the radiographic thickness equivalent of the test objects, containing copper wires ranging from 0.1 mm (0.005 in.) to 0.4 mm (0.015 in.) diameter.
    d. A series of copper shims ranging in thickness from 0.1 mm (0.005 in.) to 0.4 mm (0.015 in.), containing 1/2T and 1T holes.

Answer 181

c. A plastic block with the radiographic thickness equivalent of the test objects, containing copper wires ranging from 0.1 mm (0.005 in.) to 0.4 mm (0.015 in.) diameter.

Question 182

1. Thermal resistance is:
   a. analogous to electrical current.
   b. a material’s impedance to heat flow.
   c. proportional to the fourth power of emissivity.
   d. proportional to the rate of heat flow.

Answer 182

b. a material’s impedance to heat flow.

Question 183

2. Conductive heat transfer can take place:
   a. across a vacuum.
   b. from a hair dryer blowing on an object.
   c. between a heat lamp and a distant object.
   d. between dissimilar metals in contact with each other.

Answer 183

d. between dissimilar metals in contact with each other.

Question 184

3. The infrared/thermal energy emitted from a target surface:
   a. occurs only in a vacuum.
   b. is inversely proportional to surface emissivity.
   c. is proportional to the fourth power of the absolute surface temperature.
   d. is totally absorbed by water vapor in the air.

Answer 184

c. is proportional to the fourth power of the absolute surface temperature.

Question 185

4. Thermal radiation reaching the surface of a thermally opaque object will only be:
   a. absorbed by the surface.
   b. absorbed and reflected by the surface.
   c. reflected by the surface.
   d. transmitted and absorbed by the surface.

Answer 185

b. absorbed and reflected by the surface.

Question 186

5. The following spectral band is included in the infrared spectrum:
   a. 0.1 to 5.5 μm
   b. 0.3 to 10.6 μm
   c. 0.4 to 20 μm
   d. 0.75 to 100 μm

Answer 186

d. 0.75 to 100 μm

Question 187

6. As a surface cools, the peak of its radiated infrared energy:
   a. shifts to longer wavelengths.
   b. shifts to shorter wavelengths.
   c. remains constant if emissivity remains constant.
   d. remains constant even if emissivity varies.

Answer 187

a. shifts to longer wavelengths.

Question 188

7. A graybody surface with an emissivity of 0.04 would be:
   a. transparent to infrared radiation.
   b. a fairly good emitter.
   c. almost a perfect reflector.
   d. almost a perfect emitter.

Answer 188

c. almost a perfect reflector.

Question 189

8. If a surface has an emissivity of 0.35 and a reflectivity of 0.45, its transmissivity would be:
   a. impossible to determine without additional information.
   b. 0.80.
   c. 0.10.
   d. 0.20.

Answer 189

d. 0.20.

Question 190

9. The spectral band in which glass transmits infrared radiation most efficiently is the:
   a. 3 to 6 μm region.
   b. 2 to 3 μm region.
   c. 6 to 9 μm region.
   d. 9 to 11 μm region.

Answer 190

b. 2 to 3 μm region.

Question 191

10. Infrared thermal detectors:
    a. have a broad, flat spectral response.
    b. have much faster response times than photon detectors.
    c. usually require cooling to operate properly.
    d. have much greater sensitivity than photon detectors.

Answer 191

a. have a broad, flat spectral response.

Question 192

11. A diffuse reflecting surface is:
    a. a polished surface that reflects incoming energy at a complementary angle.
    b. a surface that scatters reflected energy in many directions.
    c. also called a specular reflecting surface.
    d. highly transparent to infrared radiation.

Answer 192

b. a surface that scatters reflected energy in many directions.

Question 193

12. The minimum resolvable temperature difference is a subjective measurement that depends on:
    a. the infrared imaging system’s spatial resolution only.
    b. the infrared imaging system’s measurement resolution only.
    c. the infrared imaging system’s thermal sensitivity and spatial resolution.
    d. the infrared imaging system’s minimum spot size.

Answer 193

c. the infrared imaging system’s thermal sensitivity and spatial resolution.

Question 194

13. The spatial resolution of an instrument is related to the:
    a. thermal resolution.
    b. spectral bandwidth.
    c. system responsivity.
    d. instantaneous field of view and the working distance.

Answer 194

d. instantaneous field of view and the working distance.

Question 195

14. The noise equivalent temperature difference (NETD) of a thermal infrared imager tends to:
    a. improve as the target temperature increases.
    b. degrade as the target temperature increases.
    c. remain constant regardless of the target temperature.
    d. improve with increasing working distance.

Answer 195

a. improve as the target temperature increases.

Question 196

15. The 3 to 5 μm spectral region is well suited for:
    a. inspection using a microbolometer.
    b. measuring targets at extremely long working distances.
    c. measuring targets warmer than 200 °C (392 °F).
    d. operating at near ambient temperatures.

Answer 196

c. measuring targets warmer than 200 °C (392 °F).

Question 197

16. When measuring the temperature of glass while using a mid-wave (3 to 5 μm) infrared imaging system, which of the following steps is necessary?
    a. Use a 3.2 μm low-pass filter.
    b. Use a 5 μm high-pass filter.
    c. No filter is necessary if using the same emissivity setting used with long-wave imaging systems.
    d. Use a 3.9 μm bandpass filter.

Answer 197

d. Use a 3.9 μm bandpass filter

Question 198

17. A line scanner is best used for applications:
    a. requiring online real-time process monitoring and control of a linear thermal process.
    b. where the material is stationary.
    c. where the process speed is no greater than 3 m/s.
    d. where the maximum temperature of the material is 300 °C (572 °F).

Answer 198

a. requiring online real-time process monitoring and control of a linear thermal process.

Question 199

18. Most infrared focal plane array imagers:
    a. use more costly optics than scanning radiometers.
    b. offer better spatial resolution than scanning radiometers.
    c. offer better thermal resolution than scanning radiometers.
    d. offer less diagnostics features than scanning radiometers.

Answer 199

b. offer better spatial resolution than scanning radiometers.

Question 200

19. When measuring the temperature of a nongray target:
    a. the viewing angle is not critical.
    b. always assume a uniform emissivity.
    c. varying surface temperature differences can be ignored.
    d. errors may occur when using a variety of instruments.

Answer 200

d. errors may occur when using a variety of instruments.

Question 201

20. Thermal diffusivity is:
    a. high for metals and low for porous materials.
    b. the same for all metals.
    c. low for metals and high for porous materials.
    d. the same for all porous materials.

Answer 201

a. high for metals and low for porous materials.

Question 202

21. The term used to describe a material’s surface temperature response to a given energy input is called:
    a. diffuse reflectivity.
    b. thermal conductance.
    c. thermal effusivity.
    d. spectral transmittance.

Answer 202

c. thermal effusivity.

Question 203

UT 1. Ultrasonic waves propagate through test materials in the form of:
a. electromagnetic waves.
b. low-voltage electric fields.
c. discontinuous radio waves.
d. mechanical vibrations.

Answer 203

d. mechanical vibrations.

Question 204

UT 2. When an ultrasonic beam passes through the interface of two dissimilar materials at an angle, a new angle of sound travel takes place in the second material due to:
a. refraction.
b. attenuation.
c. rarefaction.
d. compression.

Answer 204

a. refraction.

Question 205

UT 3. The gradual loss of energy as ultrasonic vibrations travel through material is referred to as:
a. reflection.
b. refraction.
c. compression.
d. attenuation.

Answer 205

d. attenuation.

Question 206

UT 4. Ultrasonic velocities are different for different materials. These differences are primarily caused by differences in the materials’:
a. frequency and wavelength.
b. thickness and travel time.
c. elasticity and density.
d. chemistry and permeability.

Answer 206

c. elasticity and density.

Question 207

UT 5. Ultrasonic energy for immersion testing is transmitted to the test object as a compressional wave because:
a. compressional waves travel faster and will therefore reduce the distance of the interface signal.
b. liquids will only sustain compressional waves.
c. compressional waves are used with immersion testing only.
d. the higher intensity of compressional waves is necessary to overcome high attenuation in liquids.

Answer 207

b. liquids will only sustain compressional waves.

Question 208

UT 6. When inspecting coarse-grained materials, which of the following frequencies will generate a sound wave that will be most easily scattered by the grain structure?
a. 1.0 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz

Answer 208

d. 10 MHz

Question 209

UT 7. In general, shear waves are more sensitive to small discontinuities than longitudinal waves for a given frequency and in a given material because:
a. the wavelength of shear waves is shorter than the wavelength of longitudinal waves.
b. shear waves are not as easily dispersed in the material.
c. the direction of particle vibration for shear waves is more sensitive to discontinuities.
d. the wavelength of shear waves is longer than the wavelength of longitudinal waves.

Answer 209

a. the wavelength of shear waves is shorter than the wavelength of longitudinal waves.

Question 210

UT 8. The ability of transducers to detect echoes from small discontinuities is a definition of:
a. resolution.
b. sensitivity.
c. definition.
d. gain.

Answer 210

b. sensitivity.

Question 211

UT 9. Which of the following will create a resonance condition in a specimen?
a. Continuous longitudinal waves.
b. Pulsed longitudinal waves.
c. Pulsed shear waves.
d. Continuous shear waves.

Answer 211

a. Continuous longitudinal waves.

Question 212

UT 10. The display on most basic pulse-echo ultrasonic instruments consists of:
a. automatic read-out equipment.
b. an A-scan presentation.
c. a B-scan presentation.
d. a C-scan presentation.

Answer 212

b. an A-scan presentation.

Question 213

UT 11. In a basic pulse-echo ultrasonic instrument, the component that produces the voltage that activates the search unit is called:
a. an amplifier.
b. a receiver.
c. a pulser.
d. a synchronizer.

Answer 213

c. a pulser.

Question 214

UT 12. The primary purpose of reference blocks is to:
a. aid the operator in obtaining maximum back reflections.
b. obtain the greatest sensitivity possible from an instrument.
c. provide a known reflecting area in calibrating an instrument.
d. establish the size and orientation of a discontinuity.

Answer 214

c. provide a known reflecting area in calibrating an instrument.

Question 215

UT 13. The general use of distance-amplitude correction is to compensate for:
a. attenuation, distance, and beam spread.
b. amplitude of noise signals.
c. velocity changes.
d. vertical nonlinearity in the ultrasonic instrument.

Answer 215

a. attenuation, distance, and beam spread.

Question 216

UT 14. In area-amplitude ultrasonic standard test blocks, the flat-bottom holes in the blocks are:
a. all the same diameter.
b. different in diameter, increasing in size of 1/64 in. (0.0156 in.) 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.

Answer 216

b. different in diameter, increasing in size of 1/64 in. (0.0156 in.) increments from the No. 1 block to the No. 8 block.

Question 217

UT 15. Which of the following factors has the least influence on the amount of energy reflected from a discontinuity?
a. Size of the discontinuity.
b. Orientation of the discontinuity.
c. Discontinuity type.
d. Test frequency.

Answer 217

d. Test frequency.

Question 218

UT 16. The ability to locate discontinuities that are close together within the material is called:
a. resolution.
b. sensitivity.
c. effectiveness.
d. phase delay.

Answer 218

a. resolution.

Question 219

UT 17. Lack of parallelism between the entry surface and the back surface:
a. may result in a screen pattern that does not contain back reflection indications.
b. makes it difficult to locate discontinuities that lie parallel to the entry surface.
c. usually indicates a porous condition existing in the metal.
d. will decrease the penetrating power of the test.

Answer 219

a. may result in a screen pattern that does not contain back reflection indications.

Question 220

UT 18. Significant errors in ultrasonic thickness measurement can occur if:
a. test velocity is kept constant.
b. the velocity of propagation deviates substantially from an assumed constant value for a given material.
c. water is used as a couplant between the transducer and the part being measured.
d. longitudinal waves are used.

Answer 220

b. the velocity of propagation deviates substantially from an assumed constant value for a given material.

Question 221

UT 19. In contact testing, shear waves can be induced in the test material by:
a. placing an X-cut quartz crystal directly on the surface of the material and coupling through a film of oil.
b. using two transducers on opposite sides of the test specimen.
c. using an angle-beam transducer with the transducer mounted on a plastic wedge so that sound enters the part at an angle.
d placing a spherical acoustic lens on the face of the transducer.

Answer 221

c. using an angle-beam transducer with the transducer mounted on a plastic wedge so that sound enters the part at an angle.

Question 222

UT 20. The most commonly used method of producing shear waves in a test part when inspecting by the immersion method is by:
a. transmitting longitudinal waves into a part in a direction perpendicular to its front surface.
b. using two crystals vibrating at different frequencies.
c. using a low-frequency transducer.
d. angulating the transducer to the proper angle with respect to the entry surface of the test part.

Answer 222

d. angulating the transducer to the proper angle with respect to the entry surface of the test part.

Question 223

UT 21. In immersion testing, proof that the search unit is normal (perpendicular) to a flat entry surface is indicated by:
a. maximum reflection amplitude from the entry surface.
b. elimination of water multiples.
c. maximum reflection amplitude from the back surface.
d. maximum amplitude of the initial pulse.

Answer 223

a. maximum reflection amplitude from the entry surface.

Question 224

UT 22. In immersion testing, the water distance between the search unit and the test piece:
a. should be as small as possible.
b. will have no effect on the test.
c. should be the same as the water distance used during calibration.
d. should be as great as possible.

Answer 224

c. should be the same as the water distance used during calibration.

Question 225

UT 23. Generally, the best UT technique for detecting discontinuities oriented along the fusion zone in a welded plate is:
a. an angle-beam contact method employing surface waves.
b. an immersion test using surface waves.
c. a resonance technique.
d. an angle-beam method using shear waves.

Answer 225

d. an angle-beam method using shear waves.

Question 226

UT 24. Thin sheet may be inspected for laminar discontinuities with the ultrasonic wave directed normal (perpendicular) to the surface by observing:
a. the amplitude of the front surface reflection.
b. the multiple reflection pattern.
c. the amplitude of the initial pulse.
d. signals that “walk” or move along the time base as the transducer is scanned over the sheet.

Answer 226

b. the multiple reflection pattern.

Question 227

UT 25. Ultrasonic inspection of castings is occasionally impractical because of:
a. extremely small grain structure typical in castings.
b. coarse grain structure.
c. uniform flow lines.
d. random orientation of discontinuities.

Answer 227

b. coarse grain structure.

Question 228

UT 26. Angle-beam testing of plate will often miss:
a. cracks that are perpendicular to the sound wave.
b. inclusions that are randomly oriented.
c. laminations that are parallel to the front surface.
d. a series of small discontinuities.

Answer 228

c. laminations that are parallel to the front surface.

Question 229

UT 27. In addition to a weld area being inspected by the angle-beam technique, which additional test is typically performed to detect laminations in the base metal?
a. Through-transmission testing.
b. Guided wave testing.
c. Straight-beam testing.
d. Surface-wave testing.

Answer 229

c. Straight-beam testing.

Question 230

UT 28. An ultrasonic test using a straight-beam contact search unit is being conducted through the thickness of a flat part, such as plate. This test should detect:
a. laminar-type discontinuities with major dimensions parallel to the plane of the rolled surface.
b. transverse-type discontinuities with major dimensions at right angles to the plane of the rolled surface.
c. radial discontinuities with major dimensions along the length but radially oriented to the rolled surface.
d. rounded discontinuities at the edges of the rolled plate.

Answer 230

a. laminar-type discontinuities with major dimensions parallel to the plane of the rolled surface.

Question 231

29. UT techniques are useful in testing laminate and sandwich construction test objects for:
    a. paint thickness.
    b. bond integrity.
    c. leakage.
    d. surface roughness.

Answer 231

b. bond integrity.

Question 232

30. UT techniques are frequently used in online automatic process control applications to measure and control:
    a. moisture content in materials.
    b. surface roughness of turbine blade castings.
    c. the thickness of cold-rolled strips, sheets, and plates.
    d. chemical activity in chemical etching processes.

Answer 232

c. the thickness of cold-rolled strips, sheets, and plates.

Question 233

UT 31. Which of the following statements about field inspection applications of UT is true?
a. Manual and automatic systems can be used for field inspections.
b. Because the equipment is large and bulky, field inspections are difficult, at best.
c. Aircraft and other field maintenance inspections usually require three persons: one to manipulate the transducer, one to monitor the instrument, and one to record results.
d. Digital displays must be used for outdoor inspection because of the limited brightness of screen displays.

Answer 233

a. Manual and automatic systems can be used for field inspections.

Question 234

UT 32. Which of the following waves is able to follow a surface around a curve?
a. Longitudinal wave.
b. Shear wave.
c. Surface wave.
d. Lamb wave.

Answer 234

d. Lamb wave.

Question 235

1. VT could be best described as:
   a. detection of near surface anomalies and various color variations.
   b. optical detection of surface anomalies and checking conformance to specification.
   c. evaluation of metallurgical conditions via electronic microscope.
   d. examination for a wide variety of discontinuities open to or just below the surface

Answer 235

b. optical detection of surface anomalies and checking conformance to specification.

Question 236

VT 2. What element of the eye is analogous to a digital camera, converting a light pattern into electronic signals?
a. Eye muscle.
b. Iris.
c. Lens.
d. Retina.

Answer 236

d. Retina.

Question 237

VT 3. Illumination varies inversely as the square of the distance between the source and the point on the surface increases. What is this law called?
a. Inverse square law.
b. Cosine law.
c. Generation of light law.
d. Lambert’s law.

Answer 237

a. Inverse square law.

Question 238

VT 4. When measuring surface roughness, Ra is defined as what?
a. Average distance between the highest and lowest points.
b. Average waviness from crest to trough.
c. Average distance of the profile to the mean line.
d. Parameter of friction between contact surfaces.

Answer 238

c. Average distance of the profile to the mean line.

Question 239

VT 5. What is the minimum luminance recommended by the Illuminating Engineering Society (IES) for task lighting with medium contrast and small size detection desired?
a. 100 lx
b. 200 lx
c. 500 lx
d. 2000 lx

Answer 239

c. 500 lx

Question 240

VT 6. What is the direction of view called in a borescope or videoscope when viewing 45° off the straight-ahead direction of the probe?
a. Forward slant.
b. Forward oblique.
c. Forespective.
d. Angulated.

Answer 240

b. Forward oblique.

Question 241

VT 7. How many bundles are there in a fiber-optic borescope and what are they called?
a. One; monochromatic bundle.
b. Two; light guide and image guide.
c. Two; light guide and CCD cable bundle.
d. Three; light guide, image guide, and fiber sheath.

Answer 241

b. Two; light guide and image guide.

Question 242

VT 8. What is a commonly evident surface discontinuity visible to the unaided eye following forming?
a. Forging bursts at the center of the billet.
b. Laminations at end preparations of plate for welding.
c. Edge breaks in temper-rolled sheets of steel.
d. Segregation between pours.

Answer 242

c. Edge breaks in temper-rolled sheets of steel.

Question 243

VT 9. What type of cracking occurs at the termination point of a weld made by tungsten inert gas welding?
a. Crater crack.
b. Hot tearing.
c. Cold cracking.
d. Hot cracking.

Answer 243

a. Crater crack.

Question 244

VT 10. What is pillowing corrosion on aircraft lap joints, typically on aircraft skins, usually attributed to?
a. Misalignment corrosion of fasteners used to attach the skins to the airframe.
b. Stretching of the skins beyond their yield points over time.
c. Expansion of corrosion products under the skins.
d. Twisting of the airframe during tight turns and similar maneuvers.

Answer 244

c. Expansion of corrosion products under the skins.

Question 245

VT 11. When inspecting welds for discontinuities located by VT, which of the following discontinuities is usually judged the least detrimental, depending on its depth?
a. Undercut.
b. Cracks.
c. Lack of fusion.
d. Incomplete penetration.

Answer 245

a. Undercut.

Question 246

VT 12. How can the heat-affected zone (HAZ) of carbon steel welds be made visible?
a. Etchants to enhance the visibility of the microstructure.
b. High-frequency ultrasonic microscopic means.
c. Color-contrast penetrating liquids.
d. Arrays of temperature-sensitive markings.

Answer 246

a. Etchants to enhance the visibility of the microstructure.

Question 247

VT 13. Reflectance is a measure of:
a. the reactance of a coating.
b. the mirror-like reflectance of a surface.
c. the amount of artificial light at the inspection surface.
d. the flatness of a finish coating

Answer 247

b. the mirror-like reflectance of a surface.

Question 248

14. A datum:
    a. is a theoretical point identified on the blueprint.
    b. is a theoretical point, axis, or plane, derived from actual part features.
    c. is a feature controlled by two separate datums.
    d. has form only in terms of itself.

Answer 248

b. is a theoretical point, axis, or plane, derived from actual part features.

Question 249

15. Color order systems describe color by:
    a. value and brightness saturation.
    b. primary and secondary colors.
    c. value, hue, and saturation.
    d. value of the primary color constituents.

Answer 249

c. value, hue, and saturation.

Question 250

16. A concave mirror can be helpful by:
    a. focusing the image viewed.
    b. diverging and optically reversing small images.
    c. converging and optically reversed small images.
    d. increasing the light returned to the inspector.

Answer 250

b. diverging and optically reversing small images.