MT GINZEL BRO 1-150 Flashcards
- For demagnetizing large parts, field reversals are usually _________.
A. lower frequency than for small parts
B. higher frequency than for small parts
C. the same frequency as for small parts
D. not needed
A. lower frequency than for small parts
- For best demagnetization results using a coil with A.C. and passing parts
through it you should
A. pass the part through with its long axis parallel to the coil axis
B. hold the part close to the coil
C. both a and b
D. switch the current on only when the part is centred along its length in the
coil
C. both a and b
- The advantage of using reversing D.C. for demagnetization is
A. low heating effect
B. deep penetration
C. only one reversal is needed
D. all of the above
B. deep penetration
- The magnetic flux in a part increases as applied field is increased. The flux
moves along the virgin curve of the hysteresis curve
A. once each cycle of applied A.C. field
B. twice each cycle of applied A.C. field
C. only once when the part is completely demagnetized
D. for paramagnetic materials only
C. only once when the part is completely demagnetized
- Small parts can be demagnetized in multiple lots by passing them through an
A.C. coil provided they are
A. stacked in a basket
B. apart in single layer
C. oriented long axis parallel to coil axis
D. both b and c
D. both b and c
- For rings and hollow parts a handy means of A.C. demagnetization is
A. using a yoke
B. a central conductor using decreasing current
C. surge pulses through prod contacts
D. swinging field technique
B. a central conductor using decreasing current
- The most likely tool you would use to determine if a part has been adequately
demagnetized is the
A. Hall detector
B. field meter
C. electrogram
D. magnetometer
B. field meter
- A problem with doing a head shot on a ball bearing is
A. arc burns damage the surface
B. no defects are found
C. the field is distorted too much
D. they cannot be demagnetized
A. arc burns damage the surface
- The two classifications of media in MPI are
A. fluorescent and non-fluorescent
B. wet and dry
C. magnetic and para-magnetic
D. high temperature and low temperature
B. wet and dry
- Prior to the use of magnetic particles to detect flaws by magnetic methods,
flaws could be located in iron pieces using
A. Hall detectors
B. ordinary magnetic compasses
C. electro scopes
D. electromagnetic resonance
B. ordinary magnetic compasses
- The ampere is a unit of
A. electric current
B. electromotive force
C. electromagnetic force
D. magnetic intensity
A. electric current
- Total current in two parallel conductors can be determined by knowing the
distance between the conductors and the
A. dielectric constant of air
B. resistivity of the conductors
C. right hand rule
D. magnetic force exerted per unit length of wire
D. magnetic force exerted per unit length of wire
- The direction assigned to a magnetic dipole moment vector is determined by
A. coil size
B. conductor diameter
C. current magnitude
D. direction of current flow
D. direction of current flow
- The units Webers per square metre (Wb/m^2) are used to quantify a
A. magnetic induction field
B. magnetic dipole
C. magnetic monopole
D. magnetic force
A. magnetic induction field
- Magnetic field lines are
A. always concentric rings
B. symbolic only, and used to indicate spatial direction of the field
C. a result of the van Allan belts
D. of uniform density
B. symbolic only, and used to indicate spatial direction of the field
- In a ferromagnetic material, a region where all the “atomic moments” are
aligned parallel to each other is called a
A. magnetic zone
B. confederation
C. domain
D. magnetic junta
C. domain
- A void in an otherwise homogenous magnetized material presents itself as a
point magnetic dipole. This is the basis for
A. magnetic particle flaw detection
B. multi frequency eddy current
C. para-magnetism
D. de-magnetisation
A. magnetic particle flaw detection
- Magnetic properties of materials are a result of
A. electric currents on the atomic and sub-atomic scale
B. the strong nuclear force
C. the ratio of protons to neutrons in the material
D. the weak nuclear force
A. electric currents on the atomic and sub-atomic scale
- When discussing magnetization and its effects the magnetic induction field is
usually represented by the letter
A. B
B. H
C. M
D. Z
A. B
- When discussing magnetization and its effects the magnetic field intensity, or
as its also called, the magnetic field is represented by the letter
A. B
B. H
C. M
D. Z
B. H
- The phenomenon whereby the magnetization of a ferromagnetic sample lags the
applied cyclic magnetic field is referred to as
A. phase lag
B. Doppler effect
C. hysteresis
D. demagnetization
C. hysteresis
- When a hysteresis curve is generated for a ferromagnetic material, a magnetic
field remains in the material when the applied field is returned to zero. This
field is called the
A. coercive force
B. induction field
C. residual induction
D. resultant vector
C. residual induction
- The value of H applied to bring the residual value of B to zero is called
A. saturation field
B. demagnetization value
C. induction coercive force
D. phase reversal factor
C. induction coercive force
- In order to be detectable by magnetic particle testing, a flaw must
A. be surface breaking
B. be no deeper than 1mm below the surface
C. produce a perturbation of the induction field at the test surface
D. all of the above
C. produce a perturbation of the induction field at the test surface
- To detect a flaw by magnetic particle methods, techniques are developed to
A. maximize field perturbations in the region of a flaw
B. optimize retentivity of the material
C. propagate the flaw by Barkhausen jumps
D. all of the above
A. maximize field perturbations in the region of a flaw
- Sensitivity of the magnetic particle method depends on the
A. absolute magnitude of the induced field perturbation
B. spatial gradient of the induced field perturbation
C. magnitude of the applied field
D. surface flux density of the test piece
B. spatial gradient of the induced field perturbation
- Magnetic particle testing has an advantage over liquid penetrant testing
because it can
A. be used on ferromagnetic materials
B. locate surface defects
C. locate subsurface defects
D. be cheaper to use
C. locate subsurface defects
- Magnetic particle testing is a practical test method to inspect.
A. glass
B. ceramics
C. aluminum castings
D. none of the above
D. none of the above
- When a discontinuity causes the magnetic field lines to be forced out of the
specimen into the air, the field in the air is called a
A. force field
B. leakage field
C. flux field
D. flaw field
B. leakage field
- Magnetic particles are available in many colours to
A. indicate degree of permeability
B. optimize visibility
C. indicate degree of rententivity
D. permit the inspector to choose a colour that will not clash with his/her
clothing
B. optimize visibility
- Which is not an essential step in magnetic particle testing?
A. establish a suitable magnetic flux in the test piece
B. application of magnetic particles
C. examination of test piece
D. post cleaning of test piece to remove magnetic particles
D. post cleaning of test piece to remove magnetic particles
- Inherent discontinuities are formed during
A. initial melting and refining of the metal
B. primary processing
C. secondary processing and manufacturing
D. in-service use
A. initial melting and refining of the metal
- The deeper a subsurface defect gets below the surface
A. the greater the flux leakage it produces
B. the harder it gets to magnetize the part
C. the larger it must be to be detectable
D. all of the above
C. the larger it must be to be detectable
- In order to detect a flaw by magnetic particle testing the magnetic field must
A. alternate
B. pulse
C. run parallel to the principal plane of the flaw
D. intercept the principal plane of the flaw
D. intercept the principal plane of the flaw
- The cgs unit of magnetizing force (H) is the
A. oersted
B. gauss
C. tesla
D. Weber
A. oersted
- The cgs unit of flux density (B) is the
A. oersted
B. gauss
C. tesla
D. Weber
B. gauss
- If the ends of a long bar magnet are bent to form a circle and the ends
perfectly fused together the result will be
A. the magnet will no longer attract ferromagnetic material
B. a circular magnetic field
C. no magnetic flux leakage field
D. all of the above
D. all of the above
- A bar magnet would be considered to be
A. circularly magnetized
B. longitudinally magnetized
C. electromagnetically poled
D. cross-polarized
B. longitudinally magnetized
- Which of the following is not a characteristic of magnetic flux lines?
A. they attract each other
B. they form continuous loops
C. they do not cross each other
D. they decrease in intensity with distance from the surface
A. they attract each other
- Inside a bar magnet magnetic flux lines are considered to flow from
A. north to south
B. south to north
C. east to west
D. west to east
B. south to north
- The direction of magnetic lines of force around a current carrying conductor
is
A. parallel to the conductor
B. at right angles to the conductor
C. 45 degrees out of phase to the applied current
D. parallel or perpendicular to the conductor depending on which current flow
convention is used
B. at right angles to the conductor
- If a nail is brought to a bar magnet it is held by the magnet. If another nail
is now brought to touch the first nail it is held to the first nail.
Subsequent nails can be held in a long chain. This is a result of
A. induced magnetism
B. nail bonding
C. domain transfer
D. natural attraction of nail points to nail heads
A. induced magnetism
- The end of the compass needle that points towards the northern region of the
earth is called
A. the north seeking pole
B. the magnetic north pole
C. the magnetic south pole
D. both a and b
D. both a and b
- The magnetic north pole is located
A. at 90° north latitude
B. somewhere in northern Canada
C. at the north geographic pole
D. at Greenwich England
B. somewhere in northern Canada
- A single line of force represents the unit of magnetic flux in a field. This
is called a(n)
A. oersted
B. gauss
C. weber
D. maxwell
D. maxwell
- A magnet can lose its magnetism by
A. heating
B. hammering
C. both a and b
D. no known means
C. both a and b
- Removal of magnetism from a part is termed
A. domain scattering
B. demagnetization
C. stress relieving
D. the Hall effect
B. demagnetization
- A permanent magnet configured such that both north and south poles are
adjacent is usually termed a
A. longitudinal magnet
B. circular magnet
C. parallel magnet
D. horseshoe magnet
D. horseshoe magnet
- The “image” of a magnetic field produced by placing a magnet under a paper and
sprinkling iron fillings on the top of the paper is called
A. magnetic projection
B. magnetic holography
C. a magnetograph
D. flux painting
C. a magnetograph
- In direct current flow electric circuits, the unit of current is the
A. ampere
B. ohm
C. mho
D. volt
A. ampere
- In alternating current electric circuits the unit of current flow is the
A. ampere
B. ohm
C. volt
D. deci Bell
A. ampere
- Magnetic lines of force are
A. isolated mono-poles
B. elongated bi-poles
C. manifestations of the “string-theory”
D. imaginary concepts for mapping magnetic fields
D. imaginary concepts for mapping magnetic fields
- Electric current which at regular intervals reverses its direction of flow is
called
A. AC
B. DC
C. alternating
D. both a and c
D. both a and c
- Opposition to electric current flow in a D.C. circuit is termed
A. ohmage
B. resistance
C. reactance
D. reluctance
B. resistance
- The unit of electrical resistance is the
A. ampere
B. coulomb
C. ohm
D. volt
C. ohm
- The unit of potential difference in an electric circuit is the
A. ampere
B. ohm
C. volt
D. Coulomb
C. volt
- A ferromagnetic material surrounded by a current carrying coil becomes
A. diamagnetic
B. magnetized
C. an electromagnet
D. both b and c
D. both b and c
- The unit of inductance is the
A. farad
B. henry
C. Coulomb
D. abvolt
B. henry
- The ability of a material to emit visible light while being irradiated by UV
light is called
A. fluorescence
B. phosphorescence
C. iridescence
D. Birefringence
A. fluorescence
- The typical duration of a coil shot is
A. a fraction of a second
B. 1 second
C. 2 seconds
D. 5 seconds
A. a fraction of a second