The top limit of human listening to is approximately:
A) 20Hz
B) 20kHz
C) 20MHZ - ANSB) 20kHz
A usual frequency used for ultrasonic checking out of welds is:
A) 2.25MHZ
B) 2.25kHz
C) 2.25Hz - ANSA) 2.25MHZ
Do transverse (shear) waves in a strong journey quicker or slower than longitudinal
(Compressional) waves? - ANSSlower
True or False?
The power carried through a wave is proportional to the rectangular of the amplitude. - ANSTrue
The lower in energy of an ultrasonic wave as it travels thru a cloth is called:
A) Amplitude
B) Amplification
C) Attenuation - ANSC) Attenuation
Piezoelectric crystals can:
A) Change mechanical pulses into electrical pulses
B) Change electric pulses into mechanical pulses
C) Both A and B - ANSC) Both A and B
The herbal frequency of a given piezoelectric transducer is determined with the aid of:
A) The amplitude of the voltage carried out
B) The transducer thickness
C) Neither of the above. The frequency is about by way of the cloth being inspected and can't
be modified. - ANSB) The transducer thickness
Name one piezoelectric cloth: - ANSQuartz and lead metaniobate
In conventional ultrasonics the wave is injected into the specimen as a:
, A) Continuous wave that the herbal frequency of the transducer.
B) Short pulse containing numerous oscillations at the natural frequency - ANSB) Short pulse
containing numerous oscillations at the natural frequency
Why is good acoustic touch between the transducer and the check specimen wanted? -
ANSUltrasonic waves of the frequency utilized in inspection do no longer travel a ways in air, so
desirable coupling among the transducer and the specimen is wanted
True or false?
A couplant is simplest wanted if the surface is difficult - ANSFalse
In A-scan display the vertical displacement of the trace is calibrated to symbolize:
A) The amplitude of the meditated wave
B) The length of the reflector
C) Distance - ANSA) The amplitude of the contemplated wave
In A-scan show the horizontal displacement of the trace is calibrated to represent:
A) The amplitude of the pondered wave
B) The size of the reflector
C) Distance - ANSC) Distance
In what unit is the gain manipulate (or attenuator) marked? - ANSdB (decibels)
Which type of show offers a cross-sectional view displaying the duration and intensity of
discontinuities? - ANSB-Scan
Give an instance of a device wherein the complete specimen is immersed in water, which acts
as the couplant. - ANSOn-line examination of plate defects together with laminations in a
metallic mill
True or False?
Acoustic emission is predicated on detecting very small amounts of mechanical energy
launched from such things as developing cracks or structural discontinuities under load. -
ANSTrue
True or False?
The plate and weld floor must constantly be floor easy previous to ultrasonic examination. -
ANSFalse