990+ Non Destructive Testing and Evaluation Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .

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301.	A continuous linear indication along the edge of a new fillet weld would most likely be a:
A.	Crater crack
B.	Fatigue crack
C.	Stress corrosion crack
D.	Heat affected zone hydrogen crack
Answer» D. Heat affected zone hydrogen crack

discuss

302.	Ferromagnetic material is:
A.	Strongly attracted by a magnet
B.	Capable of being magnetized
C.	Both (a) and (b)
D.	Not capable of being magnetized
Answer» C. Both (a) and (b)

discuss

303.	The retentivity of a material describes:
A.	The ease with which it can be magnetized
B.	The depth of the magnetic field in the part
C.	The length of time required to demagnetise it
D.	The ability to retain the magnetic field
Answer» D. The ability to retain the magnetic field

discuss

304.	Which of the following can be magnetised?
A.	Iron
B.	Nickel
C.	Cobalt
D.	All of the above
Answer» D. All of the above

discuss ⁽¹⁾

305.	The magnetic field is strongest when:
A.	The magnetising voltage is flowing
B.	The magnetising current is flowing
C.	The material exhibits high coercive forces
D.	The magnetising current is not flowing
Answer» B. The magnetising current is flowing

discuss

306.	The unit usually used to denote flux density is the:
A.	Gauss
B.	Henry
C.	Farad
D.	Ampere
Answer» A. Gauss

discuss

307.	Which statement is true when related to magnetic lines of force?
A.	They never cross
B.	They are most dense at the poles of a magnet
C.	They seek the path of least resistance
D.	All of the above
Answer» D. All of the above

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308.	Magnetic lines of force:
A.	Travel in straight lines
B.	Form a closed loop
C.	Are randomly oriented
D.	Overlay in highly ferromagnetic materials
Answer» B. Form a closed loop

discuss

309.	The areas on a magnetised part from which the magnetic field is leaving or returning into the part are called:
A.	Salient points
B.	Defects
C.	Magnetic poles
D.	Nodes
Answer» C. Magnetic poles

discuss

310.	The magnetism which remains in a piece of magnetisable material after the magnetising force has been removed is called the:
A.	Tramp field
B.	Residual field
C.	Damped field
D.	Permanent field
Answer» B. Residual field

discuss

311.	Which technique is the most sensitive?
A.	Continuous
B.	Residual
C.	Interrupted
D.	Counter current
Answer» A. Continuous

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312.	The point at which the magnetism in a material cannot be increased even though the magnetising force continues to increase is known as the:
A.	Salient pole
B.	Saturation point
C.	Residual point
D.	Remnant point
Answer» B. Saturation point

discuss

313.	An electric current through a copper wire:
A.	Creates a magnetic field around the wire
B.	Creates magnetic poles in the wire
C.	Magnetises the wire
D.	Does not create a magnetic field
Answer» A. Creates a magnetic field around the wire

discuss

314.	A longitudinal surface crack in a circularly magnetised part will cause:
A.	The magnetic field to die out
B.	A decrease in permeability
C.	A magnetic leakage field
D.	A current to flow
Answer» C. A magnetic leakage field

discuss

315.	The type of current that is best suited to detect surface discontinuities is:
A.	DC
B.	AC
C.	Pulsating DC
D.	Half wave
Answer» B. AC

discuss

316.	Retentivity:
A.	Represents the ability to induce magnetism in a ferromagnetic body by an outside magnetising force
B.	Represents the ability of a material to resist the establishment of magnetic flux within it
C.	Represents the ability of a material to retain a portion of the magnetic field set up in it after the magnetising force has been removed
D.	Is not a term used in magnetic particle testing
Answer» C. Represents the ability of a material to retain a portion of the magnetic field set up in it after the magnetising force has been removed

discuss

317.	Demagnetisation:
A.	May be easy or difficult depending on the type of material
B.	Is easy for materials having a high coercive force
C.	Is always most difficult in materials retaining a high residual field
D.	All of the above answers are correct
Answer» A. May be easy or difficult depending on the type of material

discuss

318.	What rule describes the direction of current flow (+ to -) when lines of magnetic force surround a conductor?
A.	Left hand rule
B.	Right hand rule
C.	Flux rule
D.	Reluctance rule
Answer» B. Right hand rule

discuss

319.	The proper number of ampere-turns for a given test specimen is determined by:
A.	Its length
B.	The material and its diameter
C.	Both the length and the material
D.	Its diameter and length
Answer» D. Its diameter and length

discuss

320.	An electrical yoke produces:
A.	A longitudinal field
B.	A circular field
C.	Alternating fields
D.	A swinging field
Answer» A. A longitudinal field

discuss

321.	In longitudinal magnetisation the proper term for calculating magnetising force is:
A.	Amperes
B.	Ampere-turns
C.	Watts
D.	Ohms
Answer» B. Ampere-turns

discuss

322.	The amount of amperage used for magnetic particle inspection using the prod method is determined from the:
A.	Type of material
B.	Distance between the prods
C.	Diameter of the part
D.	Total length of the part
Answer» B. Distance between the prods

discuss

323.	Which of the following is the most effective method for the detection of extremely deep-lying defects:
A.	Dry residual method using DC surge
B.	Wet continuous method using half wave rectified current
C.	Wet residual method
D.	Dry continuous method using half wave rectified current with prods
Answer» D. Dry continuous method using half wave rectified current with prods

discuss

324.	What method provides greater sensitivity, particularly in locating subsurface discontinuities?:
A.	Continuous
B.	Residual
C.	Circular
D.	Longitudinal
Answer» A. Continuous

discuss

325.	Which type of current has a ‘skin effect’:
A.	AC
B.	DC
C.	Half wave rectified
D.	Full wave rectified
Answer» A. AC

discuss

326.	When using the wet continuous method, the flow of suspension from the hose should be shut off:
A.	Immediately after applying the current
B.	Immediately before applying the current
C.	While the current is flowing
D.	Thirty seconds before applying the current
Answer» C. While the current is flowing

discuss

327.	The area of maximum induced field strength using a yoke is:
A.	At the north pole of the yoke
B.	At the south pole of the yoke
C.	The area directly between the poles
D.	on the outside of pole pieces
Answer» C. The area directly between the poles

discuss

328.	The strongest magnetic field in a coil is at the:
A.	Outside edge
B.	Inside edge
C.	Centre
D.	End
Answer» B. Inside edge

discuss

329.	What equipment is used to determine if a part has been demagnetised?
A.	A magnet on the part
B.	A field meter
C.	A survey meter
D.	Careful observation for clinging magnetic particles
Answer» B. A field meter

discuss

330.	Which of the following will best define surface cracks?
A.	Half wave rectified AC
B.	DC
C.	AC
D.	Surge current
Answer» C. AC

discuss

331.	Applying the theory of the ‘Right Hand Rule’, a longitudinal surface defect in a round bar is detected by ‘current passing in a direction parallel to the direction of expected defects’ because:
A.	The current direction is in line with the defect
B.	The magnetic field is at right angles to the defect
C.	It makes no difference
D.	The magnetic field is parallel to the defect
Answer» B. The magnetic field is at right angles to the defect

discuss

332.	Why are magnetic particles available in different colours?
A.	For colour contrast with the part surface
B.	To enhance the detection of indications
C.	For both a and b
D.	Different colours are used with different magnetic flux values
Answer» C. For both a and b

discuss

333.	A magnetic particle build-up from a discontinuity is strongest when the discontinuity is oriented:
A.	180o to the magnetic field
B.	45o to the magnetic field
C.	90o to the magnetic field
D.	90o to the current flow
Answer» C. 90o to the magnetic field

discuss

334.	Why is it preferable to disassemble parts before magnetic particle inspection?
A.	Disassembly makes all surface areas visible
B.	Interfaces will create leakage fields which may confuse the inspection
C.	It is usually easier to handle the disassembled parts
D.	All of the above
Answer» D. All of the above

discuss

335.	Fluorescent magnetic particle indications should be inspected under
A.	Fluorescent light
B.	Any light
C.	Black light
D.	Neon light
Answer» C. Black light

discuss

336.	Why should one avoid using a high velocity flow of a wet testing media over the test area
A.	It may wash away a fine or lightly held indication
B.	This is not a problem
C.	It may splash particle into eyes
D.	None of the above are correct
Answer» A. It may wash away a fine or lightly held indication

discuss

337.	What are the three causes of non-relevant indications?
A.	Lack of fusion, change of section thickness, grinding cracks
B.	Change of section thickness, very high amperage, drilled hole near surface
C.	Very high amperage, drilled hole near surface, blow holes
D.	Drilled hole near surface, very high amperage, lack of fusion
Answer» B. Change of section thickness, very high amperage, drilled hole near surface

discuss

338.	Magnetic particle inspection is not a reliable method of detecting
A.	Laps
B.	Deep seated cavities
C.	Cracks
D.	Seams
Answer» B. Deep seated cavities

discuss

339.	A defect open to the surface produces an indication which is
A.	Sharp and distinct
B.	Wide and indefinite
C.	Criss-cross
D.	High and fuzzy
Answer» A. Sharp and distinct

discuss

340.	Wet magnetic bath strength is checked by which of the following
A.	Specific gravity
B.	Optical density
C.	Settling test
D.	None of the above
Answer» C. Settling test

discuss

341.	When preparing a bath it is important to have the bath strength at a proper level, as too many particles can result in:
A.	Lowering the test amperage
B.	Having to increase the magnetising current
C.	Masking the indications
D.	None of the above
Answer» C. Masking the indications

discuss

342.	Magnetic particle is a non-destructive examination method used for:
A.	Locating surface discontinuities
B.	Near surface discontinuities
C.	Both a and b
D.	Material separation
Answer» C. Both a and b

discuss

343.	A part is adaptable to magnetic particle inspection if
A.	It is attached to an electrostatic field
B.	The material is ferromagnetic
C.	The material is non-ferrous
D.	The material is an electric conductor
Answer» B. The material is ferromagnetic

discuss

344.	The permeability of a material describes:
A.	The ease with which it can be magnetized
B.	The depth of the magnetic field in the part
C.	The length of time required to demagnetise it
D.	The ability to retain the magnetic field
Answer» A. The ease with which it can be magnetized

discuss

345.	If a crack exists in a circular magnet, the attraction of magnetic particles to the crack is caused by:
A.	A coercive force
B.	A leakage field
C.	A Doppler effect
D.	A high reluctance at the crack
Answer» B. A leakage field

discuss

346.	The flux within and surrounding a magnetised part or around a conductor carrying a current is known as:
A.	Saturation point
B.	Magnetic field
C.	Ferromagnetic
D.	Paramagnetic
Answer» B. Magnetic field

discuss

347.	A metal that is difficult to magnetise is said to have:
A.	High permeability
B.	Low permeability
C.	High reluctance
D.	Low retentivity
Answer» B. Low permeability

discuss

348.	Which residual field is most difficult to demagnetise?
A.	Longitudinal
B.	Circular
C.	Vector
D.	Binodal
Answer» B. Circular

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349.	Which brings out surface indications most clearly?
A.	AC
B.	DC
C.	Pulsed DC
D.	DC with surge
Answer» A. AC

discuss

350.	To detect lengthwise defects on the inside diameter of hollow parts, you should:
A.	Pass current through it
B.	Magnetise with a coil
C.	Pass current through a central conductor
D.	Increase the amperage used
Answer» C. Pass current through a central conductor

discuss

990+ Non Destructive Testing and Evaluation Solved MCQs

A continuous linear indication along the edge of a new fillet weld would most likely be a:

Ferromagnetic material is:

The retentivity of a material describes:

Which of the following can be magnetised?

The magnetic field is strongest when:

The unit usually used to denote flux density is the:

Which statement is true when related to magnetic lines of force?

Magnetic lines of force:

The areas on a magnetised part from which the magnetic field is leaving or returning into the part are called:

The magnetism which remains in a piece of magnetisable material after the magnetising force has been removed is called the:

Which technique is the most sensitive?

The point at which the magnetism in a material cannot be increased even though the magnetising force continues to increase is known as the:

An electric current through a copper wire:

A longitudinal surface crack in a circularly magnetised part will cause:

The type of current that is best suited to detect surface discontinuities is:

Retentivity:

Demagnetisation:

What rule describes the direction of current flow (+ to -) when lines of magnetic force surround a conductor?

The proper number of ampere-turns for a given test specimen is determined by:

An electrical yoke produces:

In longitudinal magnetisation the proper term for calculating magnetising force is:

The amount of amperage used for magnetic particle inspection using the prod method is determined from the:

Which of the following is the most effective method for the detection of extremely deep-lying defects:

What method provides greater sensitivity, particularly in locating subsurface discontinuities?:

Which type of current has a ‘skin effect’:

When using the wet continuous method, the flow of suspension from the hose should be shut off:

The area of maximum induced field strength using a yoke is:

The strongest magnetic field in a coil is at the:

What equipment is used to determine if a part has been demagnetised?

Which of the following will best define surface cracks?

Applying the theory of the ‘Right Hand Rule’, a longitudinal surface defect in a round bar is detected by ‘current passing in a direction parallel to the direction of expected defects’ because:

Why are magnetic particles available in different colours?

A magnetic particle build-up from a discontinuity is strongest when the discontinuity is oriented:

Why is it preferable to disassemble parts before magnetic particle inspection?

Fluorescent magnetic particle indications should be inspected under

Why should one avoid using a high velocity flow of a wet testing media over the test area

What are the three causes of non-relevant indications?

Magnetic particle inspection is not a reliable method of detecting

A defect open to the surface produces an indication which is

Wet magnetic bath strength is checked by which of the following

When preparing a bath it is important to have the bath strength at a proper level, as too many particles can result in:

Magnetic particle is a non-destructive examination method used for:

A part is adaptable to magnetic particle inspection if

The permeability of a material describes:

If a crack exists in a circular magnet, the attraction of magnetic particles to the crack is caused by:

The flux within and surrounding a magnetised part or around a conductor carrying a current is known as:

A metal that is difficult to magnetise is said to have:

Which residual field is most difficult to demagnetise?

Which brings out surface indications most clearly?

To detect lengthwise defects on the inside diameter of hollow parts, you should: