MMET 402 EXAM 2 QUESTIONS WITH
100% CORRECT ANSWERS
Which type of screen presentation displays a profile or cross-sectional view of the test
specimen?
a. A-scan
b. B-scan
c. C-scan
d. All of the above - Answer- b. B-scan
Which type of screen presentation displays a plan-type view of the location and size of
the test specimen features?
a. A-scan
b. B-scan
c. C-scan
d. All of the above - Answer- c. C-scan
Which type of screen presentation displays the amount of received ultrasonic energy as
a function of time?
a. A-scan
b. B-scan
c. C-scan
d. All of the above - Answer- a. A-scan
Which type of transducer will have better resolution?
a. A slightly damped transducer
b. A small size and low frequency transducer
c. A highly damped transducer
d. All of the above - Answer- c. A highly damped transducer
Why aren't real defects commonly used in calibration and reference standards?
a. They are more difficult to detect with NDT methods
b. They are always the same size and length
c. It is cost prohibitive to produce them
d. Both A and C - Answer- c. It is cost prohibitive to produce them
Within a given material, the speed of sound:
a. Is constant
b. Decreases with distance from the transducer
c. Increases with distance from the transducer
d. None of the above - Answer- a. Is constant
, What is the correct formula for calculating the wavelength when the wave velocity and
frequency are known? (𝜆 = wavelength, f = frequency, V = velocity) - Answer- 𝜆 =𝑉/𝑓
Another name for a compressional wave is: - Answer- longitudinal wave
The transducer that contains the thinnest piezoelectric crystal is a:
a. 1 MHz transducer
b. 5 MHz transducer
c. 15 MHz transducer
d. 25 MHz transducer - Answer- d. 25 MHz transducer
The amount of beam divergence from a crystal is primarily dependent on the: - Answer-
frequency and crystal size
Under most circumstances, which of the following frequencies would result in the best
resolving power?
a. 1 MHz
b. 5 MHz
c. 10 MHz
d. 25 MHz - Answer- d. 25 MHz
When the motion of the particles of a medium is parallel to the direction of propagation,
the wave being transmitted is called a: - Answer- longitudinal wave
When the motion of the particles of a medium is transverse to the direction of
propagation, the wave being transmitted is called a: - Answer- shear wave
Most commercial ultrasonic testing is accomplished using frequencies between: -
Answer- 0.2 and 25 MHz
In an A-scan presentation, the horizontal base line represents: - Answer- the elapsed
time or distance
In an A-scan presentation, the amplitude of vertical indications on the display represents
the: - Answer- amount of ultrasonic sound energy returning to the transducer
Which of the following test frequencies would generally provide the best penetration in a
30 cm (12 in.) thick specimen of coarse-grained steel?
a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz - Answer- a. 1 MHz
100% CORRECT ANSWERS
Which type of screen presentation displays a profile or cross-sectional view of the test
specimen?
a. A-scan
b. B-scan
c. C-scan
d. All of the above - Answer- b. B-scan
Which type of screen presentation displays a plan-type view of the location and size of
the test specimen features?
a. A-scan
b. B-scan
c. C-scan
d. All of the above - Answer- c. C-scan
Which type of screen presentation displays the amount of received ultrasonic energy as
a function of time?
a. A-scan
b. B-scan
c. C-scan
d. All of the above - Answer- a. A-scan
Which type of transducer will have better resolution?
a. A slightly damped transducer
b. A small size and low frequency transducer
c. A highly damped transducer
d. All of the above - Answer- c. A highly damped transducer
Why aren't real defects commonly used in calibration and reference standards?
a. They are more difficult to detect with NDT methods
b. They are always the same size and length
c. It is cost prohibitive to produce them
d. Both A and C - Answer- c. It is cost prohibitive to produce them
Within a given material, the speed of sound:
a. Is constant
b. Decreases with distance from the transducer
c. Increases with distance from the transducer
d. None of the above - Answer- a. Is constant
, What is the correct formula for calculating the wavelength when the wave velocity and
frequency are known? (𝜆 = wavelength, f = frequency, V = velocity) - Answer- 𝜆 =𝑉/𝑓
Another name for a compressional wave is: - Answer- longitudinal wave
The transducer that contains the thinnest piezoelectric crystal is a:
a. 1 MHz transducer
b. 5 MHz transducer
c. 15 MHz transducer
d. 25 MHz transducer - Answer- d. 25 MHz transducer
The amount of beam divergence from a crystal is primarily dependent on the: - Answer-
frequency and crystal size
Under most circumstances, which of the following frequencies would result in the best
resolving power?
a. 1 MHz
b. 5 MHz
c. 10 MHz
d. 25 MHz - Answer- d. 25 MHz
When the motion of the particles of a medium is parallel to the direction of propagation,
the wave being transmitted is called a: - Answer- longitudinal wave
When the motion of the particles of a medium is transverse to the direction of
propagation, the wave being transmitted is called a: - Answer- shear wave
Most commercial ultrasonic testing is accomplished using frequencies between: -
Answer- 0.2 and 25 MHz
In an A-scan presentation, the horizontal base line represents: - Answer- the elapsed
time or distance
In an A-scan presentation, the amplitude of vertical indications on the display represents
the: - Answer- amount of ultrasonic sound energy returning to the transducer
Which of the following test frequencies would generally provide the best penetration in a
30 cm (12 in.) thick specimen of coarse-grained steel?
a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz - Answer- a. 1 MHz
