D c b a a low intensity fast uv flash a macro lens uv

D)
C)
B)
A)
a low intensity fast UV flash
a macro lens
UV sensitive film
a tripod
For colour photography of both visible and fluorescent indications it is recommended to use 257.
D)
C)
B)
A)
"incandescent" film
normal daylight film
film with greater than 500 ASA speed
none of the above, colour photography is not recommended for NDT purposes.
Polarizing filters are used in MPI indication photography for what purpose? 258.
D)
C)
B)
A)
to reduce highlights and reflections
to remove infra-red light
to remove orange light
to intensify yellow-green light
ESTestMaker Questions
43

UV filters used in fluorescent indication photography ;are sometimes called 259.
D)
C)
B)
A)
Kodak filters
haze filters
crossed nichols
polarizing filters
When photographing MPI indications it is often a good practice to expose extra frames using higher
and lower f-stops to compensate for unforeseen conditions. This practice is called
260.
D)
C)
B)
A)
"hedging your bets"
betting to show
bracketing
full-stopping
Which of the following is an advantage of video tape recording of MPI indications?
261.
D)
C)
B)
A)
availability to do subsequent image enhancement
cost
ease and speed to produce
both a and b
The fact that only some magnetic domains resume a random orientation when the magnetizing field is
removed accounts for what?
262.
D)
C)
B)
A)
permeability
coercivity
retentivity
nuclear magnetic resonance (NMR)
The total coercive force of a magnetized piece is always 263.
D)
C)
B)
A)
greater than the maximum magnetizing force
less than the maximum magnetizing force
equal to the saturation force
determined by the residual field reduction equation
The requirement for multiple switching of polarity and simultaneously reducing current amplitude is
had for
264.
D)
C)
B)
A)
pulsed A.C. magnetization
swinging field techniques
D.C. demagnetization methods
surge magnetization
ESTestMaker Questions
44

In the reversing D.C. method of demagnetization the current is gradually reduced to 265.
D)
C)
B)
A)
the negative coercive force level
the positive coercive force level
zero
negative saturation
When a D.C. bench unit, that does not have the step down demagnetisation option built in, is used to
demagnetize a part with a cable wrap, how is current reversal achieved?
266.
D)
C)
B)
A)
re-wrapping the coils
manually switching cable connections
manually switching the current selector
none of the above, it cannot be used for demag purposes
Field strength of a coil wrap magnetization set up can be increased by
267.
D)
C)
B)
A)
reducing diameter of coil
reducing current
reducing turns
reducing fill factor
Almost anything MPI tested can be demagnetized to an acceptable level using reversing D.C.
methods; but its disadvantage is
268.
D)
C)
B)
A)
severe arc burns
over heating of some surface finishes
low production rates
large equipment and dangerously high currents are used
When demagnetizing a ring shaped object by passing it through a coil you would 269.