NDT UT LEVEL 1 EXAM QUESTIONS
WITH VERIFIED ANSWERS
Ultrasonic Waves that travel along the surface of a material and whose particle
motion is elliptical. - ANSWER Rayleigh Waves (Surface/Love Waves)
In a material with a given velocity, when the frequency is increased, the
wavelength will __? - ANSWER Decrease
Ultrasonic vibrations can be propagated only in the longitudinal mode in which
media? - ANSWER Machine Oil (Liquid)
If a 5.0 Mhz transducer is substituted for a 2.25 Mhz transducer ( 2.25 old/5.0
new), what would be the effect on the wavelength of the longitudinal wave
mode produced in the test specimen? (i.e. shorter, longer or the same)? -
ANSWER Wavelength would decrease (Mhz increase = wavelength decrease)
The velocity of a sound in a material is dependent upon the: Frequency of the
wave, Wavelength, Material Properties, and Vibration Cycle. - ANSWER
Material Properties
To vary or change the wavelength of sound being used to test a part, you would
change the: Sound Wave Frequency, Diameter of the Transducer, Electrical
Pulse Voltage, Pulse Repetition Rate. - ANSWER Sound Wave Frequency
Ultrasonic vibrations are commonly used to: Examine materials for
discontinuities, examine materials for thickness, examine materials for
mechanical properties, all of the above. - ANSWER All of the above
Another name for a compressional wave: - ANSWER Longitudinal Wave
Another name for Rayleigh Waves: - ANSWER Surface Waves
When the motion of the particles of a medium is parallel to the direction of the
propagation, the wavelength transmitted is called a: - ANSWER Longitudinal
Wave
, When the motion of the particles of a medium is transverse to the direction of
the propagation, the wavelength transmitted is called a: - ANSWER Shear
Wave
"25 million cycles per second" can also be stated as: - ANSWER 25 megahertz
A term used in ultrasonics to express the rate at which sound waves pass
through various substances is: - ANSWER Velocity
Which of the following modes of vibration has the greatest velocity? -
ANSWER Longitudinal Wave (Approximately 2x faster than Shear, Surface
waves are 90% speed of shear and 45% of Longitudinal)
Sound waves of a frequency beyond the hearing range of the human ear are
referred to as ultrasonic waves, these have a frequency greater than
approximately: - ANSWER 20,000 hertz (20Hz to 20,000 Hz or 20Khz is
within hearing range)
"100,000 cycles per second" can be written as: - ANSWER 100 kilohertz
Increasing the frequency of an ultrasound longitudinal wave will have what
impact on velocity: (Increase, decrease or no change) - ANSWER No change in
velocity (Only if material properties change or wave mode is changed)
If the velocity of a wave is 6.3 km per second at 1/2 inch below the surface,
what is the velocity at 2 inches below the surface? - ANSWER Same as the
velocity at 1/2 inch
Surface (Rayleigh) Waves traveling on the top face of a block: Are not reflected
from a sharp edge corner. Are reflected from a sharp edge corner. Travel
through the sharp edge corner and are reflected from the lower edge. Are
absorbed by a sharp corner. - ANSWER Are reflected from a sharp edge corner
Surface (Rayleigh) Waves traveling on the top face of a block are attenuated by
the presence of: A) A curved surface. B) A heavy couplant. C) Machining
Marks and rough surfaces. D) Both B and C. - ANSWER Both B and C
WITH VERIFIED ANSWERS
Ultrasonic Waves that travel along the surface of a material and whose particle
motion is elliptical. - ANSWER Rayleigh Waves (Surface/Love Waves)
In a material with a given velocity, when the frequency is increased, the
wavelength will __? - ANSWER Decrease
Ultrasonic vibrations can be propagated only in the longitudinal mode in which
media? - ANSWER Machine Oil (Liquid)
If a 5.0 Mhz transducer is substituted for a 2.25 Mhz transducer ( 2.25 old/5.0
new), what would be the effect on the wavelength of the longitudinal wave
mode produced in the test specimen? (i.e. shorter, longer or the same)? -
ANSWER Wavelength would decrease (Mhz increase = wavelength decrease)
The velocity of a sound in a material is dependent upon the: Frequency of the
wave, Wavelength, Material Properties, and Vibration Cycle. - ANSWER
Material Properties
To vary or change the wavelength of sound being used to test a part, you would
change the: Sound Wave Frequency, Diameter of the Transducer, Electrical
Pulse Voltage, Pulse Repetition Rate. - ANSWER Sound Wave Frequency
Ultrasonic vibrations are commonly used to: Examine materials for
discontinuities, examine materials for thickness, examine materials for
mechanical properties, all of the above. - ANSWER All of the above
Another name for a compressional wave: - ANSWER Longitudinal Wave
Another name for Rayleigh Waves: - ANSWER Surface Waves
When the motion of the particles of a medium is parallel to the direction of the
propagation, the wavelength transmitted is called a: - ANSWER Longitudinal
Wave
, When the motion of the particles of a medium is transverse to the direction of
the propagation, the wavelength transmitted is called a: - ANSWER Shear
Wave
"25 million cycles per second" can also be stated as: - ANSWER 25 megahertz
A term used in ultrasonics to express the rate at which sound waves pass
through various substances is: - ANSWER Velocity
Which of the following modes of vibration has the greatest velocity? -
ANSWER Longitudinal Wave (Approximately 2x faster than Shear, Surface
waves are 90% speed of shear and 45% of Longitudinal)
Sound waves of a frequency beyond the hearing range of the human ear are
referred to as ultrasonic waves, these have a frequency greater than
approximately: - ANSWER 20,000 hertz (20Hz to 20,000 Hz or 20Khz is
within hearing range)
"100,000 cycles per second" can be written as: - ANSWER 100 kilohertz
Increasing the frequency of an ultrasound longitudinal wave will have what
impact on velocity: (Increase, decrease or no change) - ANSWER No change in
velocity (Only if material properties change or wave mode is changed)
If the velocity of a wave is 6.3 km per second at 1/2 inch below the surface,
what is the velocity at 2 inches below the surface? - ANSWER Same as the
velocity at 1/2 inch
Surface (Rayleigh) Waves traveling on the top face of a block: Are not reflected
from a sharp edge corner. Are reflected from a sharp edge corner. Travel
through the sharp edge corner and are reflected from the lower edge. Are
absorbed by a sharp corner. - ANSWER Are reflected from a sharp edge corner
Surface (Rayleigh) Waves traveling on the top face of a block are attenuated by
the presence of: A) A curved surface. B) A heavy couplant. C) Machining
Marks and rough surfaces. D) Both B and C. - ANSWER Both B and C
