QUIZ) ASNT L3 MT 4

61. Which of the following would be most applicable for the detection of sub-surface flaws in a high

permeability welded structure?

A. Wet fluorescent-AC

B. Dry visible-FWDC

C. Dry visible-HWDC

D. Wet fluorescent-DC

62. Which of the statements below are not typically employed to prevent or minimize prod marks on parts

A. Use padded prods

B. Reduce prod spacing and magnetizing current

C. Make sure prods are in firm contact with the part when current is turned on or off

D. Increase prod spacing and magnetizing current

63. For the detection of indications at the surface of a part which of the following statements would not be

an advantage of alternating current over direct current?

A. The rapid reversal of the field imparts mobility to the particles

B. Eqipment for a given output of magnetizing force can be lighter less costly and better adapted to portability

C. It is better for locating very fine non-metallic stringers lying just below the surface

D. The "dancing" of particles help it to move to the area of leakage fields and to form stronger indications

64. Long slender particle develop stronger polarity than globular shaped particles due to their

A. L/D ratio

B. density

C. low retentivity

D. low permeability

65. What precautions would not be be employed to prevent or minimize prod marks on parts?

A. Use padded prods

B. Reduce prod spacing and magnetizing current

C. Make sure prods are in firm contact with the part when current is tumed on or off

D. Use prods made of 50% copper

66. Which of the following is the most effective method of demagnetization?

A. AC with variable voltage

B. DC with reversing and step down control

C. AC half-rectified wave

D. DC surge and build-up

67. A long straight magnetic particle indication detected in rolled bar and running parallel to the long axis of

the bar, could be classified as a

A. lamination

B. cooling crack

C. forging lap

D. seam

68. While inspecting several magnetic parts having highly finished surfaces it is noted that several have

indications ranging from quite sharp to feathery and / fuzzy in appearance. There appears to be no similar

pattern or relation as to locations or general direction on the parts. After demagnetization and re- inspection

the indications do not reappear, What is the most probable cause of this condition?

A. Metallic indications

B. Nonmetallic inclusions

C. Permeability changes with the material

D. Magnetic writing

69. When shortest magnetization times are required which type of magnetic particle suspension would you

specify for a semi-automated MT bench test?

A. Low viscosity oil with coarse particles

B. High viscosity oil with small particles

C. Water- based carrier with small particles

D. Dry powder dusted over the part

70. The major disadvantage of portable MT equipment is the limited amount of

A. cable available

B. current available

C. milliampereage available

D. portability

71. The dye on fluorescent magnetic particles readily absorbs ultraviolet light in the ( ) range and emits

light in the range of ( )

A. 365nm, 520~550nm

B. 520~550nm，365nm

C. 1000lx, 365nm

D. 365nm, 320~400nm

72. For an AC field the direction of the resulting magnetic field varies through

A. 90 degrees

B. 360 degrees

C. 180 degrees

D. remains constant

73. Which of the following might be the most likely source of masking fatigue cracks on abrupt section

changes during a test where the current required by the procedure was 500A in both directions?

A. Circular magnetization of 500A

B. Longitudinal magnetization of 500A

C. Circular magnetization of 950A

D. Longitudinal magnetization of 950A

74. The accumulation of particles on the test surface due to a magnetic leakage field is property called

A. a discontinuity

B. a defect

C. an indication

D. a false indication

75. A service induced crack-like indication discovered in material subjected to elevated temperatures with

stress below the yield strength of the material is most likely what discontinuity

A. fatigue

B. stress corrosion cracking

C. creep

D. hydrogen cracking

76. The Hall Element can be used in conjunction with gaussmeters or other devices to measure magnetic

field. The Hall sensor may be hold at a fixed distance from a current carrying wire and the gaussmeter

measure the field strength created by the current. In order to measure small field or current, What device

is added in order to obtain these readings?

A. A ferrite ring

B. A magnetodiode

C. A ferroprobe

D. A symmetric contacting concentrator

77. When using prods for magnetic particle inspection of welds, magnetization with half-wave rectified DC

A. require twice the magnetizing force as DC magnetization

B. results in greater particle mobility than with full-wave DC

C. never requires demagnetization

D. is used to check fillet welds for surface cracks

78. Powder patterns which are small and occur at the termination point of the weld identify which type of

discontinuity?

A. Surface cracks

B. Seams

C. Crater cracks

D. Change in magnetic characteristics

79. When a specification requires a magnetic particle test of a coated specimen through paint of a thickness

of 20~20㎛, the following would be an adequate practice

A. applying rather DC than AC

B. using small rather than coarse particles

C. demonstrating the sensitivity on a coated reference

D. using rather the residual than the continuous method

80. Wet fluorescent magnetic particle inspection is used in preference to non-fluorescent magnetic particles

A. when the parts are large and bulky

B. to increase the reliability of detecting surface discontinuities

C. to increase the reliability of detecting small surface discontinuities

D. to increase speed of detecting small surface discontinuities

 

 

 

answer

 

61	62	63	64	65	66	67	68	69	70
C	D	C	A	D	B	D	D	C	B
71	72	73	74	75	76	77	78	79	80
A	A	C	C	C	A	B	C	C	D