Saturday, 3 July 2021

Important question for AKTU_exam of Non-Destructive Testing #NDT #NDT_Objective questions with answer key, LIQUID PENETRANT TESTING (PT)

 

1 LIQUID PENETRANT TESTING (PT)

1.1 Liquid Penetrant Testing Level 1 (PT-1)

1.1.1 Liquid Penetrant Testing Level 1 (PT-1) General Examination

1. Liquid penetrant testing is based on the principle of:

(a) Polarized sound waves in a liquid

(b) Magnetic domains

(c) Absorption of X rays

(d) Capillary action

2. When a small diameter tube is placed in a glass of water, water rises in the tube to a

level above the adjacent surface. This is called:

(a) Viscosity

(b) Capillary action

(c) Surface tension

(d) Barometric testing

3. How is the size of a liquid penetrant indication usually related to the discontinuity it

represents:

(a) Larger than

(b) Smaller than

(c) Equal to

(d) Not related to

4. A penetrant that is self-emulsifying is called:

(a) Solvent removable

(b) Water washable

(c) Post-emulsified

(d) Dual sensitivity method

2

5. A penetrant process which employs an emulsifier as a separate step in the penetrant

removal process is called:

(a) Solvent removable

(b) Water washable

(c) Post-emulsified

(d) Dual sensitivity method

6. A penetrant process in which excess penetrant is removed with an organic solvent is

called:

(a) Solvent removable

(b) Water washable

(c) Post-emulsified

(d) Dual method

7. Which of the following statements accurately describes the capabilities of liquid

penetrant testing?

(a) Liquid penetrant testing is useful for locating subsurface discontinuities in a

test piece

(b) Liquid penetrant testing is useful for locating discontinuities in porous

materials

(c) Liquid penetrant testing is useful for locating discontinuities which are open to

the surface in non-porous materials

(d) none of the above

8. Which of the following discontinuity types could typically be found with a liquid

penetrant test?

(a) Internal slag in a weld

(b) Internal slag in a casting

(c) Sensitization in austenitic stainless steel

(d) Fatigue cracks

3

9. Which of the following chemical elements are normally held to a minimum in liquid

penetrant materials, when testing stainless steel and titanium?

(a) Hydrogen

(b) Chlorine

(c) Carbon

(d) Oil

10. Which of the following chemical elements are normally held to a minimum in liquid

penetrant materials when testing nickel based alloys?

(a) Sulphur

(b) Oxygen

(c) Carbon

(d) Nitrogen

11. Which of the following is the most desirable method of pre-cleaning a test piece prior

to penetrant testing?

(a) Sand blasting

(b) Vapour degreasing

(c) Emery cloth

(d) Wire brushing

12. Which of the following pre-cleaning processes is not recommended?

(a) Detergent cleaning

(b) Vapour degreasing

(c) Shot blasting

(d) Ultrasonic cleaning

13. A wire brush should be used for pre-cleaning:

(a) When grease and oil must be removed

(b) Only as a last resort

(c) When rust is to be removed

(d) When grinding burrs must be removed

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14. A hydrometer is used to measure:

(a) Penetrant viscosity

(b) Specific gravity of water based wet developers

(c) Penetrant specific gravity

(d) Cleaner specific gravity

15. Visible, solvent removable penetrants are most advantageous for:

(a) Inspecting parts with rough surfaces

(b) Inspecting batches of small parts

(c) Inspecting parts at remote locations

(d) Inspecting parts with porous surfaces

16. For adequate test results, the black light used in fluorescent penetrant examination

should provide what minimum black light intensity at the test surface?

(a) 100 foot candles per square centimetre

(b) 1000 microwatts per square centimetre

(c) 800 foot candles

(d) 35 microwatts per square centimetre

17. What minimum warm-up time is required for acceptable performance of a mercury

Vapour arc black light?

(a) None

(b) 2 minutes

(c) 5 minutes

(d) 10 minutes

18. Which of the following penetrants contains an emulsifying agent?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

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19. Which of the following penetrants must be treated with an emulsifier prior to water

removal?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

20. What is the function of an emulsifier?

(a) To remove the excess penetrant

(b) To develop indications with a post emulsifiable penetrant system

(c) To assist penetration with a post emulsifiable penetrant system

(d) To make a post emulsifiable penetrant water washable

21. An oil based emulsifier is called:

(a) Hydrophilic

(b) Hydrophobic

(c) Lipophilic

(d) Fluoroscopic

22. A water based emulsifier is called:

(a) Hydrophilic

(b) Hydrophobic

(c) Lipophilic

(d) Fluoroscopic

23. Methylene chloride, isopropyl, alcohol, naptha and mineral spirits are examples of:

(a) Emulsifiers

(b) Developers

(c) Solvent removers

(d) None of the above

6

24. What type of solvent removers may be used with a solvent removable penetrant?

(a) Any organic solvent

(b) Only the cleaner recommended by the manufacturer of the penetrant

(c) Any alcohol based solvents

(d) Only chlorinated hydrocarbons

25. Which of the following is a prerequisite for a penetrant test?

(a) Developer must be applied in a thin, even coat

(b) Any surface coatings or soils must be completely removed

(c) All traces of penetrant materials should be removed after testing is complete

(d) The test object must be non-magnetic

26. Which of the following types of pre-cleaning processes may be used for liquid

penetrant testing?

(a) Wire brushing only

(b) Detergent and water only

(c) Vapour degreasing only

(d) Any process that leaves the part clean and dry, does not harm the part and is

compatible with the penetrant materials

27. What is the likely result of incomplete removal of all excess penetrant from the test

piece surface?

(a) Formation of false indications

(b) Formation of relevant indications

(c) Exaggeration of the size of relevant indications

(d) None of the above

28. What is the preferred pre-cleaning process for removal of oil and grease :

(a) Steam cleaning with a added acid

(b) Vapour degreasing

(c) Steam cleaning

(d) Ultrasonic cleaning

7

29. Which pre-cleaning method may be used with either a solvent or a detergent solution?

(a) Ultrasonic cleaning

(b) Steam cleaning

(c) Detergent wash

(d) Vapour degreasing

30. What is the danger associated with using a wire brush during pre-cleaning?

(a) Bristles from the wire brush may cause false indications

(b) Contaminants from the wire brush may cause delayed hydrogen cracking of

high carbon steels

(c) The wire brush may not adequately remove organic soils

(d) The wire brush may close or smear metal over

31. What is the preferred method of removing paint prior to performing a penetrant

testing?

(a) Sand blast

(b) Chemical removers

(c) Power wire brush

(d) Shot blast

32. What additional surface preparation or cleaning must be performed on a machined or

ground aluminium casting prior to penetrant testing?

(a) Vapour degreasing

(b) Etching

(c) Detergent wash

(d) Nothing

33. Acceptable methods of penetrant application are:

(a) Spraying

(b) Dipping

(c) Brushing

(d) All of the above

8

34. The time period during which penetrant remains on the surface of the test piece is

called:

(a) Dwell time

(b) Soaking time

(c) Fixing time

(d) Development time

35. Excess penetrant removal is a two step process with which of the following penetrant

methods?

(a) Water washable

(b) Post emulsifiable

(c) Solvent removable

(d) Liquid oxygen applications

36. A developer aids penetrant bleed out because of:

(a) Adequate removal of the excess penetrant

(b) Providing a contrasting background for visible dye indications

(c) Capillary action

(d) Proper emulsifier action

37. In the solvent removable penetrant process, excess penetrant is removed with:

(a) A water spray

(b) A hydrophilic scrubber

(c) A solvent spray

(d) Clean, lint free towels slightly moistened with solvent

38. Water based wet developer is applied:

(a) Immediately before removal of excess penetrant

(b) Immediately after removal of excess penetrant

(c) After a drying period following removal of excess penetrant

(d) For maximum sensitivity results

9

39. Non-aqueous wet developer is applied:

(a) Immediately before removal of excess penetrant

(b) Immediately after removal of excess penetrant

(c) After the excess penetrant is removed and part surface is dried

(d) For maximum sensitivity results

40. Dry developer is applied:

(a) Immediately before removal of excess penetrant

(b) Immediately after removal of excess penetrant

(c) After drying of the part

(d) For maximum sensitivity results

41. Typical ranges of emulsifier dwell times are:

(a) 5 to 10 minutes

(b) 30 seconds to 1 minute

(c) 1 to 3 minutes

(d) 5 to 10 minutes

42. Actual emulsification times are determined by:

(a) Experiment, during technique qualification

(b) Manufacturer's recommendations

(c) Code requirements

(d) None of the above

43. The colour of fluorescent penetrant under the presence of a UV light is:

(a) Yellow-green

(b) Red

(c) Blue

(d) Green

10

44. What action is necessary if the penetrant is inadvertently allowed to dry on the test

piece?

(a) Repeat the test, beginning with the pre-cleaning operation

(b) Re-wet the penetrant, begin dwell time again and continue

(c) Clean the penetrant off the surface and develop normally

(d) Clean the penetrant off the surface, wait 5 minutes and develop normally

45. What maximum water rinse pressure is considered safe for removal of excess

penetrant in the water washable penetrant process?

(a) As low a pressure as possible, 50 PSI maximum

(b) to 200 PSI

(c) PSI maximum

(d) to 500 PSI

46. During the water rinse step of the water washable penetrant process, what is the

desired angle of the spray to the surface?

(a) Normal

(b) 30 degrees

(c) 45 degrees

(d) 75 degrees

47. Which type of emulsifier is designed to be used as a ‘scrubber’?

(a) Hydrophilic

(b) Hydrophobic

(c) Lipophilic

(d) Fluoroscopic

48. Post cleaning is especially important when:

(a) Post emulsified penetrants are used

(b) Phosphate containing detergents are used

(c) Chlorinated hydrocarbons are used

(d) The test object will be used in a liquid oxygen environment

11

49. When using a hydrophilic emulsifier, the amount of penetrant removed is most

affected by:

(a) Solution strength and time of spray

(b) Penetrant dwell time

(c) Emulsifier dwell time

(d) Adequacy of pre-clean

50. If a mercury vapour arc black light is inadvertently turned off, how soon may it be

restarted?

(a) Immediately

(b) 5 minutes

(c) 10 minutes

(d) 15 minutes

51. Which of the following is normally prohibited as a method of removing excess

penetrant when using the solvent removable penetrant process?

(a) A water spray

(b) A hydrophilic scrubber

(c) A solvent spray

(d) Clean with lint free towels moistened with solvent

52. When performing a fluorescent penetrant examination, excess penetrant is normally

removed:

(a) By a hydrophilic scrubber

(b) Under UV light

(c) By solvent spray

(d) By vapour degreasing

53. During a visible, solvent removable penetrant test, complete penetrant removal is

indicated by:

(a) Absence of red indications on the test piece surface

(b) Clean rinse water

(c) Completion of the rinse cycle

(d) Absence of red dye on the cleaning towels

12

54. Which of the following is a function of a developer

(a) Providing a contrasting background for visible dye indications

(b) Making the penetrant water washable

(c) Penetrating into discontinuities open to the surface

(d) Dissolve organic soils on the test piece surface

55. Which of the following is a function of a developer?

(a) Providing a contrasting background for visible dye indications

(b) Accentuates presence of discontinuities by causing a penetrant indication to

spread out over a larger area

(c) Provides capillary paths to aid the bleed out process

(d) All of the above

56. Which of the following developers is applied before the drying operation?

(a) Dry

(b) Non-aqueous wet

(c) Water based wet

(d) None of the above

57. The most sensitive type of developer for the detection of fine discontinuities is:

(a) Water soluble

(b) Non-aqueous wet

(c) Dry

(d) Water suspendable

58. Which of the following is the most sensitive developer in descending order?

(a) Dry, water soluble, water suspendable

(b) Non-aqueous wet, water soluble, water suspendable ,dry

(c) Non-aqueous wet, dry, water soluble

(d) Water suspendable, water soluble, non-aqueous wet

13

59. Low sulphur and chlorine penetrant materials would be used for testing:

(a) Aluminium, steel and plastics

(b) Tool steels, chrome vanadium steel and ferritic stainless steels

(c) Austenitic stainless steels, nickel alloys and titanium

(d) Magnetic materials

60. Which type of developer may be either in suspension or a solution?

(a) Dry

(b) Non-aqueous wet

(c) Water based wet

(d) None of the above

61. The temperature of water rinse used in the water washable penetrant process should

be:

(a) 60 to 110oC

(b) 40 to 100oC

(c) 16 to 43oC

(d) 70 to 140oC

62. The danger of over washing during a water washable penetrant test is that:

(a) Excess penetrant will be removed from the test piece

(b) Penetrant will be removed from discontinuities

(c) The waste water will contain too high a concentration of penetrants

(d) A protective oxide coating on the test piece is formed

63. Which penetrant process is best suited to high production rates of many small parts?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

14

64. Which penetrant process is best suited to detect shallow discontinuities?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

65. Which penetrant process is best suited to the detection of discontinuities in a test piece

having threads and keyways?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

66. Which penetrant process is the most sensitive to detect fine discontinuities?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable fluorescent

(d) Water washable fluorescent

67. Which penetrant process is best suited for portable application in the field?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

68. Which penetrant process should be used if repeated examinations are anticipated?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

15

69. What is a disadvantage of using the fluorescent penetrant process?

(a) Lower visibility of indications

(b) Must be performed in a darkened area with aid of a UV lamp

(c) Easily washed with water

(d) High visibility of indications

70. Which of the following developers is applied by brush, spraying or dipping?

(a) Non-aqueous wet

(b) Water based wet

(c) Dry

(d) Dual sensitivity

71. Which of the following developers is applied by spray only?

(a) Non-aqueous wet

(b) Water based wet

(c) Dry

(d) Dual sensitivity

72. Which of the following developers is applied by immersion or flow on only?

(a) Non-aqueous wet

(b) Water based wet

(c) Dry

(d) Dual sensitivity

73. What is the minimum time considered necessary for dark adaptation of the eyes prior

to evaluating the results of a fluorescent penetrant test?

(a) 1 minute

(b) 2 minutes

(c) 5 minutes

(d) 10 minutes

16

74. What is the likely result of looking directly into a black light?

(a) Burning of the retina of the eye

(b) Temporary inflammation of the cornea

(c) Long term tendency toward formation of cataracts

(d) Fluorescence of the fluid in the eye

75. Which type of penetrant process would be best suited to the detection of wide, shallow

discontinuities?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

76. Which type of penetrant process affords most control of test sensitivity level?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

77. Which type of penetrant process is least susceptible to over washing?

(a) Solvent removable

(b) Water washable

(c) Post emulsifiable

(d) Fluorescent

78. What is a disadvantage of the solvent removable penetrant process?

(a) It is the least sensitive of the penetrant processes

(b) It is not well suited for use on rough surfaces

(c) It is highly portable

(d) No water is required for its use

79. Which of the following is the proper first step in removal of excess penetrant when

using the solvent removable penetrant process?

(a) Immerse the test piece in solvent

(b) Spray the test piece with water

(c) Wipe the test piece surface with clean, lint free towels slightly moistened

(d) All of the above is correct






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