QUIZ) ASNT L3 MT 3

41. The bulk indicator is designed and normally used for an assessment of magnetic leakage fields as a

practical check on the external demagnetization state of an object. The indicators commonly used for

checking external field levels after a magnetic particle test normally have a range of about 1 to 2mT

(10 to 20 Gauss). Positive and negative readings represent which pole?

A. Positive readings represent north and negative readings represent south

B. Positive readings represent south and negative readings represent north

C. Negative readings represent 10 Gauss and positive readings represent 20 Gauss

D. Readings are in reference to a differential magnetic field and do not represents poles

42. Assuming operators are fully qualified which is the best means of insuring consistent part processing in

spite of operator differences?

A. Having a detailed written procedure for each type of part to be processed

B. Having an approved operator training and certification program

C. Periodic supervisory observation of operators at work

D. Having a requirement that each operator be certified as being qualified at Levels I or II in accordance

with SNT-TC-1A

43. Non relevant indications may be caused by

A. fatigue cracks

B. lack of fusion at a weld surface

C. a casting defect

D. part geometry

44. The set-up of a production magnetic particle inspection line is usually limited to or restricted by the

A. material composition

B. part size

C. acceptance standards

D. heat treatment specified

45. An aircraft quality 3 inch(I.D) steel cadmium plated nut was cut in half using a fluid regulated circular

saw for visual examination of the plating cross section. Upon close inspection no buring was seen on the

cutting surface of the nuts. The plating condition of the halves was wavy or ripply in appearance. It was

noticed that two(2) nut halves were highly magnetized and stuck like two(2) horseshoe magnets when put

together. This over magnetized condition could have been caused by

A. the circular cutting action of the saw usage

B. the plating process in which the cadmium coat or layer was applied

C. since the nut was aircraft quality the over magnetized condition could have been caused by a previous

step in which the nut was magnetic particle inspected leaving a residual field undetected

D. the magnetic properties typical of 4130 steel

46. circular magnetization will detect most discontinuities that

A. are between forty-five and ninety degrees to the line of force

B. are between zero and forty-five degrees to the line of force

C. contain a north and south pole with flux leakage

D. are subsurface and parallel to the axis of the flux leakage force

47. When performing circular magnetization with prods a prod spacing at less than 3 inches(75mm) is not

practical because

A. localized heating causes the particles to clump together

B. the particles tend to band around the prods making interpretation difficult

C. the prods may touch causing arcing

D. the magnetic particles cannot be applied to this small space

48. The sudden breaking of a direct current which causes a transient current to be induced is referred to as

A. parallel magnetization

B. multidirectional magnetization

C. induced longitudinal magnetization

D. quick break magnetization

49. When two or more magnetizing forces operating in difficult directions are simultaneously applied to a

ferromagnetic material a field is produced having a direction which is determined by the relative

strengths and directions of the applied magnetic forces. Such a field is called a

A. distorted field

B. longitudinal field

C. trigonometric or theoretical field

D. resultant or vector field

50. When using prods which one of the following discontinuities could be detected?

A. A discontinuity with the major direction lying transverse to an imaginary line drawn between the prods

B. A discontinuity with the major direction lying parallel to an imaginary line drawn between the prods

C. Discontinuities cannot be detected in this manner

D. A discontinuity which lies in a direction perpendicular to the cable attached to the controlling prod

51. To provide an adequate magnetic field produced by a coil how many ampere-turns are required on a

part 16 inches long and 2 inches in diameter when the part is placed in the center line of a coil having

a diameter of 10" and u over 500?

A. 9,000 ampere-turns

B. 5,625 ampere-turns

C. 2,812 ampere-turns

D. 5,000 ampere-turns

52. The term given to magnetization of a material such that the magnetic flux runs substantially parallel to

the part with the flux path completing itself through the air outside the material and having at least

two external poles exist is

A. parallel magnetization

B. circular magnetization

C. longitudinal magnetization

D. vectored magnetization

53. The test used to check the particle concentration of the wet inspection method bath is called

A. sensitivity test

B. setting test

C. hydrometer test

D. settling test

54. Which of the following factors need not be considered in establishing acceptance criteria for magnetic

materials inspected by the magnetic particle method?

A. Design requirements

B. Service environment

C. Orientation of indications

D. Permeability of material

55. Determine the cross sectional area of a 16" diameter coil

A. 8 square inches

B. 64 square inches

C. 128 square inches

D. 201 square inches

56. Prolonged or repeated periods of magnetization are often necessary for polymer or slurry base

suspensions because

A. it is harder to magnetize

B. it takes longer to magnetize

C. of slower inherent magnetic particle mobility in the high viscosity vehicles

D. of inherent particle mobility in the low viscosity vehicles

57. If wet particles that posses high coercive force are used they many become highly magnetized and form

objectionable

A. fluorescence

B. background

C. indications

D. magnetic writing

58. What is the maximum recommended amperage value for a part with a thickness of 1.2 inches and a prod

spacing of 5 inches when 100 to 125 amps / in of prod spacing is required?

A. 550 Amps

B. 500 Amps

C. 450 Amps

D. 625 Amps

59. Ultraviolet lamps should be connected to a constant voltage supply to

A. minimize intensity variations

B. maximize intensity variations

C. reduce bulb life

D. stabilize the wave length

60. In magnetizing a 1.5 inch diameter tube having a 0.125 inch wall with direct conduction and direct

current at 1500 amps, what is the field strength on the internal diameter?

A. Zero

B. Same as outside

C. Fifty percent of theoretical field strength

D. Approximately 150 oerstads

 

 

 

 

 

answer

41	42	43	44	45	46	47	48	49	50
A	D	D	B	C	A	B	D	D	A
51	52	53	54	55	56	57	58	59	60
B	C	D	D	D	C	B	D	A	A