Magnetic Particle Inspection Question and Answers BS EN 9934-1

Main Keywords of this article : Magnetic Particle Inspection Question and Answers BS EN 9934-1. Welding Course. TWI Course. CSWIP Course. Welding Inspection Course.

Magnetic Particle Inspection Question and Answers BS EN 9934-1

1. The magnetic field remaining in a component after the magnetising force has been switched off is called:

1. coercive force
2. saturation
3. residual magnetism
4. hysteresis

2. Powdered iron oxide suspended in paraffin and applied after the current has been switched off is a description of which method of testing?

1. Wet continuous
2. Dry continuous
3. Wet residual
4. Dry residual

3. Which brings out surface indications most clearly?

1. AC
2. DC
3. HWRAC
4. Contact current flow

4. Leakage fields are caused by:

1. a local permeability change
2. a greasy surface
3. a dirty surface
4. all of the above

5. Magnetic particles must possess:

1. high electrical conductivity
2. low density
3. high permeability
4. none of the above

6. Which of the following is the best definition of flux density?

1. the number of lines of magnetic force passing through a unit area
2. the total number of lines of force in a magnetic circuit
3. the number of lines of magnetic force per kilogram
4. the number of lines of magnetic force per amp of magnetising current

7. Magnetic particles are most often made from:

1. powdered cobalt
2. granulated nickel alloy
3. powdered magnetic iron oxide
4. plastic

 

8. When MPI is performed with non-fluorescent ink, the minimum level of white light illumination that must be present at the area under inspection is:

1. 50 lux
2. 500 lux
3. 2000 microwatts per square millimetre
4. 10 lux

9. The SI units of magnetising force are:

1. coulombs
2. tesla
3. amperes / metre
4. photons

10. Demagnetisation will most likely be required when:

1. Retentivity is high
2. Retentivity is low
3. The component is to be heat treated at a temperature above the Curie point
4. None of the above

11. Fluorescent methods would most likely not be suitable for:

1. very rough surfaces
2. very smooth surfaces
3. detecting very fine cracks
4. use with an AC yoke

12. Burmah Castrol strips will give a reasonable indication of adequate flux density if used in conjunction with:

1. A permanent magnet
2. An AC electromagnetic yoke
3. A DC electromagnetic yoke
4. All of the above

13. The graph showing the relationship between flux density and applied field strength for a ferromagnetic material is called:

1. a cantenary
2. a permeability curve
3. a parabola
4. a hysteresis loop

14. The concentration of magnetic particles in magnetic ink in bulk can be checked by:

1. A settlement test using a Sutherland flask
2. Using a Burmah Castrol strip
3. The use of standard comparitor test pieces
4. Using a Berthold penetrameter

15. The 4 ferromagnetic elements are:

1. Iron, cobalt, copper and aluminium
2. Iron, cobalt, nickel and magnesium
3. Iron, cobalt, copper and tungsten
4. Iron, cobalt, nickel and gadolinium

16. Which of the following is ferromagnetic?

1. austenitic stainless steel
2. low carbon steel
3. aluminium bronze
4. all of the above

17. The adequacy of an electromagnetic yoke is best assessed using:

1. a lift or pull off test
2. a Burmah Castrol strip
3. a calibrated ammeter
4. a calibrated voltmeter

18. The SI units of magnetic flux density are:

1. Tesla
2. ampere/metre
3. Weber
4. Gauss

19. Methods of recording MPI indications include:

1. Photography
2. Dimensioned sketches
3. The use of magnetic rubber
4. All of the above

20. Which of the following apply to the use of half wave rectified current for MPI:

1. Near surface defects cannot be detected
2. It requires the use of heavy batteries to generate the current
3. The mobility of the magnetic particles is improved by the agitation provided by the field
4. The field produced is restricted to a thin ‘skin’ in the surface of the part

21. The curie temperature of a ferromagnetic material is

1. the temperature below which it becomes non-ferromagnetic
2. the temperature at which the permeability increases to a maximum
3. the temperature above which it becomes non-ferromagnetic
4. None of the above

      23. Beyond the saturation point of a ferromagnetic material:

1. further increases in magnetising force produce no further increase in flux density
2. further increases in magnetising force produce no further increase in permeability
3. further increases in magnetising force produce no further increase in the number of
   magnetic domains
4. none of the above

23. The curie temperature of low carbon steel is about:

1. 315°C
2. 595°C
3. 770°C
4. 1400°C

24. The most thorough method of demagnetisation uses:

1. a reducing AC magnetic field
2. a stepped reversing DC magnetic field
3. a reducing DC magnetic field
4. a sledgehammer

25. Attaining three lines clearly defined on a Burmah Castrol strip:

1. proves that the flux density is at least 1 tesla
2. proves that all surface breaking defects will be found
3. gives a reasonable indication that the flux density is adequate
4. proves that all significant surface breaking defects will be found

26. One big advantage of MPI as compared with DPI is:

1. dirt filled cracks are readily detected
2. crack depth can be judged from the size of the indication
3. less operator training is needed
4. the part is not harmed

27. Wet methods of MPI are more sensitive than dry due to:

1. enhanced particle mobility
2. smaller particle size
3. larger particle size
4. a and b

28. In MPI a non-relevant indication may be caused by:

1. a surface crack
2. porosity
3. a sharp change in surface contour
4. a greasy surface

29. In MPI relevant indications are formed due to:

1. leakage fields
2. capillary forces
3. magnetostriction
4. sympathetic vibration

30. One important property of a carrier liquid for magnetic ink is:

1. low flash point
2. high flash point
3. high volatility
4. high freezing point

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SPECIFIC QUESTIONS

1. According to BS EN 9934-2, the concentration of magnetic particles in a fluorescent ink shall be:

1. 1.25 to 3.5% by volume
2. As recommended by the ink manufacturer
3. 0.1 to 0.3% by volume
4. 2 to 5% by volume

2. A type of cracking that occurs after a fusion weld has cooled to ambient temperature up to
   48 hours after welding is called:

1. chevron cracking
2. hot shortness
3. shrinkage cracking
4. hydrogen crackin

3. A small star shaped indication was noted on the cap of a weld at a stop-start.
   What type of discontinuity was indicated?

1. Fatigue crack
2. Crater crack
3. Slag inclusion
4. None of the above

4. One significant advantage of semiautomatic gas shielded flux cored arc welding as compared with standard semiautomatic gas metal arc welding is that:

1. the deposition rate is much higher
2. this technique is easier to use for vertical and overhead welds
3. the filler wire is cheaper
4. the recovery rate is higher

5. Which of the following is most likely to produce a sharply defined magnetic particle indication?

1. a linear surface discontinuity
2. a rounded surface discontinuity
3. a linear subsurface discontinuity
4. a rounded subsurface discontinuity

6. Compared with the magnetic particles used in magnetic inks those used in dry
   powder detection media are:

1. The same size
2. Smaller
3. Larger
4. Lower density

7. According to BS EN 9934-1, painted surfaces can be tested if:

1. Never
2. The paint is below 50 mm thick, non-ferromagnetic, continuous and tightly adhered
3. The paint is electrically conducting
4. (b) but the sensitivity must be verified

8. In accordance with BS EN 9934-2 the distribution of particle sizes in a magnetic ink would typically be in the range:

1. 200 to 750mm
2. 100 to 500mm
3. 1 to 50mm
4. 0.1 to 200mm

9. Heat treatment of low alloy ferritic steel welds by controlled heating to around 600°C, followed by holding for typically 1 hour per 25 mm of thickness, followed by controlled cooling best describes:

1. normalising
2. tempering
3. annealing
4. stress relief

10. Viewing conditions for non-fluorescent techniques in accordance with BS EN 9934-1
    shall be:

1. A minimum of 200 lux of monochromatic light
2. A minimum of 200 lux of white light
3. A minimum of 500 lux of monochromatic light
4. A minimum of 500 lux of white light

11. The intention of an annealing heat treatment of a low carbon steel s generally to:

1. produce a finer grain structure
2. to maximise ductility prior to cold working
3. reduce carbon contact
4. maximise hardness

12. In accordance with BS EN 9934-1 an electromagnetic yoke should be load tested using a pole spacing:

1. of 200 mm
2. of 150 mm
3. as recommended by the yoke manufacturer
4. equal to the maximum to be used during inspection

13. Defects that may be found in thermit welds include

1. shrinkage cavities
2. lack of fusion
3. porosity
4. all of the above

14. The British standard for magnetic inks is

1. BS 6072
2. BS EN 9934-2
3. BS 4069
4. BS EN 9934-3

15. In accordance with BS EN 9934-1 the minimum flux density at the component surface shall be:

1. 0.72 Tesla
2. 1.0 Tesla
3. 2000 amps/metre
4. 2 amps /metre

16. The contamination of a flaw with foreign matter will have what effect upon the sensitivity of a magnetic particle inspection?

1. Severely reduce
2. Greatly improve
3. Very little provided the contaminant is non-magnetic
4. The effect will vary according to the current used

17. Maximum sensitivity in MPI is achieved when:

1. The flaw is at right angles to the direction of the current
2. The flaw is parallel to the magnetic flux
3. The flaw is at right angles to the magnetic flux
4. The current is at right angles to the magnetic flux

18. The solid content of fluorescent inks is usually:

1. around 10% of that for non-fluorescent inks
2. around 200% of that for non-fluorescent inks
3. around 70% of that for non-fluorescent inks
4. about the same as that for non-fluorescent inks

19. Complete coverage of an item during a MPI will involve

1. Testing twice at varying current values
2. Testing with 2 different circular magnetisation methods
3. Utilising 2 methods with fields at 90 degrees to one another
4. Testing with at least 2 different techniques

20. Fluorescent inks offer a higher level of sensitivity than black because:

1. They create a larger flux leakage field
2. They create larger indications
3. The human eye is more sensitive to fluorescent indications
4. All of the above are correct

Main Keywords of this article : Magnetic Particle Inspection Question and Answers BS EN 9934-1. Welding Course. TWI Course. CSWIP Course. Welding Inspection Course.