1. An ultrasonic beam's divergence is determined by:
(a) Transducer wavelength and diameter
(b) Test specimen density
(c) The sound wave's angle of incidence
(d) The degree of damping of the ultrasonic transducer

2. When a longitudinal wave strikes an inclined interface between zero and the first critical angle, the following happens:
(a) The sound beam is totally reflected
(b) Only shear waves are produced in the second material
(c) Shear waves and longitudinal waves are produced in the second material
(d) Only longitudinal waves are produced in the second material

3. The piezoelectric material that vibrates to produce ultrasonic waves in a search unit is known as:
(a) A backing material
(b) A lucite wedge
(c) A transducer element or crystal
(d) A couplant

4. When a longitudinal wave is incident upon an inclined interface and is refracted at ninety degrees, the angle of the incident longitudinal wave is called:
(a) The Snell constant
(b) The Snell angle
(c) The mode conversion constant
(d) The first critical angle

5. When a longitudinal wave sound beam passes through an acoustic interface at some
angle other than zero degrees:
(a) Surface waves are generated
(b) Plate waves are generated
(c) Reflection, refraction and mode conversion will occur
(d) The first critical angle is reached
6. Which of the following can be a source of spurious ultrasonic signals?
(a) Surface roughness of the test piece
(b) Mode conversion within the test piece
(c) Shape or contour of the test piece
(d) All of the above
7. A noisy base line, or hash may result in:
(a) Laminations in the test piece
(b) Discontinuities at an angle to the test piece surface
(c) Large grain size
(d) Fatigue cracks
8. Sound waves which travel on the surface of a solid in a manner similar to waves on a
water surface are called:
(a) Rayleigh waves
(b) Shear waves
(c) Primary waves
(d) Compression waves
9. Lamb waves are formed in a part which has:
(a) A thickness greater that about ten wavelengths
(b) A thickness approximately equal to the wavelength
(c) Low acoustic impedance compared to the transducer crystal material
(d) A thickness of about four wavelengths
10. Which type(s) of sound wave modes will propagate through liquids?
(a) Longitudinal
(b) Shear
(c) Surface
(d) All of the above
11. When the motion of the particles of a medium is transverse to the direction of
propagation, the wave being transmitted is called a:
(a) Longitudinal wave
(b) Shear wave
(c) Surface wave
(d) Lamb wave
12. Which of the following test frequencies would generally provide the best penetration
in a 12 inch thick specimen of coarse-grained steel?
(a) 1.0 MHz
(b) 2.25 MHz
(c) 5.0 MHz
(d) 10 MHz
13. An oscilloscope display in which the screen base line is adjusted to represent the one
way distance in a test piece is called a:
(a) A scan display
(b) B scan display
(c) C scan display
(d) D scan display
14. A common use of ultrasonic testing is:
(a) Cleaning
(b) Detecting of sub-surface indications
(c) Determination of the test piece ductility
(d) Communications
15. 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) 20 kHz
(b) 2 MHz
(c) 2 kHz
(d) 200 kHz
16. Y cut crystals produce:
(a) Longitudinal waves
(b) Shear waves
(c) Lamb waves
(d) Surface waves
17. The cable that connects the ultrasonic instrument to the search unit is specially
designed so that one conductor is centred inside another. The technical name for such
a cable is:
(a) BX cable
(b) Conduit
(c) Coaxial cable
(d) Ultrasonic conductor cable grade 20
18. As ultrasonic frequency increases:
(a) Wavelength increases
(b) Wavelength decreases
(c) Sound velocity increases
(d) Sound velocity decreases
19. In an A scan presentation, the amplitude of vertical indications 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

20. Loss of the test piece back wall echo during scanning may be caused by:
(a) An abnormally homogeneous material structure
(b) A smooth entry surface on the test piece
(c) A discontinuity which is not parallel to the entry surface
(d) An opposite surface which is parallel to the entry surface
21. When a sound beam is reflected:
(a) The angle of reflection is found using Snell's law
(b) The angle of reflection equals the angle of incidence
(c) All the sound energy is reflected unless the acoustic impedance is zero
(d) Beam spread is decreased
22. Which of the following circuits converts electrical energy to ultrasonic energy?
(a) The pulse generator
(b) The transducer
(c) The transformer
(d) The power supply
23. An instrument display in which the horizontal base line represents elapsed time and
the vertical deflection represents signal amplitudes is called:
(a) A scan
(b) B scan
(c) C scan
(d) A time line display
24. Which of the following circuits provides short duration, high energy pulses which are
used to excite the transducer?
(a) The pulse generator
(b) The amplifier
(c) The transducer
(d) The clock