L1:P4 Flashcards
1)
The number of completed waves which pass a given point in a given period of time (usually 1s) is referred to as:
a. amplitude of a wave motion
b. pulse length of a wave motion
c. frequency of a wave motion
d. wavelength of a wave motion
c. frequency of a wave motion
2)
The boundary between two different materials which are in contact with each other is called:
a. an indication
b. a refractor
c. an interface
d. a marker
c. an interface
3)
When the motion of the particles of a medium is paralell to the direction of propagation, the wave being transmitted is called a:
a. longitudinal wave
b. shear wave
c. surface wave
d. lamb wave
a. longitudinal wave
4)
When the motion of the particles of a medium is at 90 degrees to the direction of propagation, the wave being transmitted is called a;
a. longitudinal wave
b. shear wave
c. surace wace
d. lamb wave
b. shear wave
5)
“25 million cycles per second” can also be stated as:
a. 25kHz
b. 2500 KHz
c. 25 MHz
d. 25 uHz
c. 25 MHz
6)
Moving a probe over a test surface either manually or automatically is referred to as:
a. scanning
b. attenuating
c. angulating
d. resonating
a. scanning
7)
**A term used in ultrasonics to express the rate at which sound waves pass through various substances is:
**
a. frequency
b. velocity
c. wavelength
d. pulse length
b. velocity
8)
An ultrasonic testing technique in which the transducer element is not paralell to the test surface is called;
a. angle beam testing
b. immersion testing
c. contact-testing
d. through-transmission
a. angle beam testing
9)
**Most manual ultrasonic testing is accomplished using frequencies between:
**
1 and 25 kHz
b. 1 and 1000 kHz
c. 0.2 and 25 MHz
d. 15 and 100 MHz
c. 0.2 and 25 MHz
10)
In an A-scan presentation, the horizontal base line represents:
a. the amount of reflected ultrasonic sound energy
b. the distance travelled bu the search unit
c. the elapsed time or distance
d. none of the above
c. the elapsed time or distance
11)
In an A-scan presentation, the amplitude of signals on the screen represents the:
a. amount of ultrasonic sound energy returning to the search unit
b. distance travelled by the search unit
c. thickness of material being tested
d. elapsed time since the ultrasonic pulse was generated
a. amount of ultrasonic sound energy returning to the search unit
12)
Which of the following test frequencies would generally provide the best penetration in a 300mm thick specimen of coarse-grained steel:
a. 1MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz
a. 1MHz
13)
An ultrasonic test using a 0 degree probe is being conduycted through the thickness of a flat part such as a plate. this test should detect;
a. laminar-type flaws with major dimensions paralell to the rolled surface
b. transverse-type flaws with major dimensions at right angles to the rolled surface
c. radial flaws with major dimensions along length but radially oriented to the rolled surface
d. none of the above
a. laminar-type flaws with major dimensions paralell to the rolled surface
14)
In ultrasonic testing, a liquid coupling medium between the crystal surface and the part surface is necessary because:
a. lubricant is reqwuired to minimise wear on the crystal surface
b. an air interface between the crystal surface and the part would almost completely reflect the ultrasonic vibrations
c. the crystal will not vibrate if placed directly in contact with the surface of the part being inspected
d. the liquid is necessary to complete the electrical circuit in the search unit
b. an air interface between the crystal surface and the part would almost completely reflect the ultrasonic vibrations
15)
During ultrasonic testing by the immersion method, it is frequently necessary to angulate the search unit when a discontinuity is located in order to:
a. avoid a large number of back reflections that could interfere with a normal test pattern
b. obtain a maxiumum response if the discontinuity is not originally oriented perpendicular to the ultrasonic beam
c. obtain the maximum number of entry surface reflections
d. obtain a discontinuity indication of the same heigh as the indication from the flat bottom hole in a reference block
b. obtain a maxiumum response if the discontinuity is not originally oriented perpendicular to the ultrasonic beam
16)
All other factors being equal, which of the following modes of vibration has the greatest velocity:
a. shear wave
b. transverse wave
c. surface wave
d. longitudinal wave
d. longitudinal wave
17)
Sound waves of a frequency beyond the hearing range of the human ear are referred to as ultrasonic waves or vibrations, and the term embraces all vibrational waves of frequency greater than approximately:
a. 2 kHz
b. 200 kHz
c. 20,000 Hz
d. 2 MHz
c. 20,000 Hz
18)
A piezoelectric material can:
a. convert a mechanical vibration into an electrical pulse
b. convert an electrical pulse into a mechanical vibration
c. be used in the construction of search units
d. all of the above
d. all of the above
19)
The velocity of sound waves is mostly dependant on:
a. the pulse length
b. the frequency
c. the material in which the sound is being transmitted and the mode of vibration
d. none of the above
c. the material in which the sound is being transmitted and the mode of vibration
20)
Which of the following crystals is the best transmitter of ultrasound:
a. lithium sulphate
b. barium titanate
c. sodium chloride
d. beryllium
b. barium titanate
21)
Calculate the wavelength in a material with a velocity of 600 m/s, using a 4 MHz probe:
a. 1.5 mm
b. 0.75mm
c. 2.5mm
d. 15mm
a. 1.5 mm
22)
The primary purpose of calibration blocks is to:
a. aid the operator in obtaining maximum back reflections
b. obtain the greatest sensitivity possible from an instrument
c. obtain a common reproducibe signal
d. none of the above
c. obtain a common reproducibe signal
23)
When testing by the suface wave method, patches of oil or dirt on the surface may:
a. block the progress of all sound
b. attenuate the sound
c. have no effect on the test
d. cause both an attentuation of sound and indications on the screen
d. cause both an attentuation of sound and indications on the screen
24)
in immersion testing, the commonly used couplant is:
a. water
b. oil
c. glycerine
d. alcohol
a. water
25)
Surface waves are more highly attentuated by:
a. a smooth surface
b. a heavy couplant
c. a thin couplant
d. both a and b
b. a heavy couplant
26)
which of the following frequencies will provide the shortest wavelength:
a. 1MHz
b. 5 MHz
c. 10 MHz
d. 25 MHz
d. 25 MHz
27)
The angle of incidence of a standard probe is:
a. greater than the angle of reflection
b. less than the angle of reflection
c. equal to the angle of reflection
d. not related to the angle of reflection
c. equal to the angle of reflection
28)
“100,000 cycles per second” can be written as:
a. 0.1 kHz
b. 10 kHz
c. 100 kHz
d. 100 MHz
c. 100 kHz
29)
The presence of a discontinuity will not produce a specific discontinuity indication on the CRT screen when using the:
a. straight beam testing method
b. surface wave testing method
c. angle beam testing method
d. through-transmission testing method
d. through-transmission testing method
30)
The depth of a discontinuity from the scanning surface cannot be determinned when using the:
a. straight beam testing method
b. through-transmission testing method
c. angle beam testing method
d. immersion testing method
b. through-transmission testing method
31)
When testing coarse-grained material, which of the following frequencies will generate a sound wave that will be most easily scattered by the grain structure:
a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz
d. 10 MHz
32)
Which of the following transducers would contain the thickest crystal:
a. a 1 MHz searcch unit
b. a 5 MHz searcch unit
c. a 15 MHz search unit
d. a 25 MHz search unit
a. a 1 MHz searcch unit
33)
When surface wave testing, indications may result from:
a. surface discontinuities
b. oil on the surface
c. dirt on the surface
d. all of the above
d. all of the above
34)
Probes constructed with a plastic wedge or standoff between the transducer element and the test piece are commonly used for:
a. dual transducer straight beam contact testing
b. angle beam contact testing
c. surface wave contact testing
d. all of the above
d. all of the above
35)
A probe containing three or more individual transducer elements acquiring different parts of the test, is often referred to as:
a. a dual transducer
b. a sandwitch transducer
c. a mosaic transducer
d. none of the above
c. a mosaic transducer
36)
**Sound can be focused by means of special curved lenses located in front of the transducer element. These adapters are referred to as:
**
a. Scrubbers
b. acoustic lens
c. angle beam adapters
d. single plane adapters
b. acoustic lens
37)
A test method in which the parts to be inspected are placed in a water bath or some other liquid couplant is called:
a. contact testing
b. immersion testing
c. surface wave testing
d. through-transmission testing
b. immersion testing
38)
The phenomenon whereby an ultrasonic sound wave changes direction when the wave crosses an interface between materials with different velocities is called:
a. refraction
b. reflection
c. penetration
d. defraction
a. refraction
39)
In a test where the transducer is not at 90 degree to the inspection surface, the angle of incidence is equal to:
a. the angle of refraction
b. the angle of reflection
c. the shear wave angle
d. half the shear wave angle
b. the angle of reflection
40)
The product of the acoustic velocity of sound and the density of the material is the factor that determines the amount of reflected energy or transmission of ultrasonic energy when it reaches an interface. This term is called;
a. acoustic impedance
b. velocity
c. wavelength
d. penetration
a. acoustic impedance
