Free ASNT Ultrasonic Questions and Answers — Questions and Answers

Question 1: The indication on the instrument display that represents the far boundary of the material being tested is called:

Hash
The initial pause
The main bang
The back surface reflection (Correct answer)

Correct answer: The back surface reflection

Explanation: In nondestructive testing (NDT), particularly in methods like ultrasonic testing, the indication on the instrument display that represents the far boundary of the material being tested is referred to as "The back surface reflection." This indication occurs due to the reflection of sound waves from the far surface of the material being tested. It is crucial in determining the thickness or integrity of the material being inspected.

Question 2: In immersion testing, the position of the transducer is often varied to transmit sound into the test part at various angles to the front surface. Such a procedure is referred to as:

Angulation (Correct answer)
Dispersion
Reflection testing
Refraction

Correct answer: Angulation

Explanation: In immersion testing, varying the position of the transducer to transmit sound into the test part at various angles to the front surface is referred to as "Angulation." This technique allows for the examination of different areas of the test part and enhances defect detection by optimizing the sound beam's interaction with the material.

Question 3: The cable that connects the ultrasonic instrument to the transducer is specially designed so that one conductor is centered inside another. The technical name for such a cable is:

BX cable
Conduit
Coaxial cable (Correct answer)
Ultrasonic conductor cable-grade 20

Correct answer: Coaxial cable

Explanation: The technical name for the cable that connects the ultrasonic instrument to the transducer, where one conductor is centered inside another, is "Coaxial cable." This design helps minimize interference and signal loss during the transmission of ultrasonic signals between the instrument and the transducer.

Question 4: The process of comparing an instrument or device with a standard is called:

Angulation
Calibration (Correct answer)
Attenuation
Correlation

Correct answer: Calibration

Explanation: The process of comparing an instrument or device with a standard to determine its accuracy and adjust it if necessary is called "Calibration." Calibration ensures that the instrument or device provides accurate and reliable measurements or readings.

Question 5: Another name for a compressional wave is:

Lamb wave
Shear wave
Longitudinal wave (Correct answer)
Transverse wave

Correct answer: Longitudinal wave

Explanation: Another name for a compressional wave is a "Longitudinal wave." In longitudinal waves, the particle motion is parallel to the direction of wave propagation, causing compression and rarefaction of the medium. This type of wave is commonly used in ultrasonic testing and other nondestructive testing methods.

Question 6: Another name for Rayleigh wave is:

Shear waves
Longitudinal waves
Transverse waves
Surface waves (Correct answer)

Correct answer: Surface waves

Explanation: Another name for Rayleigh wave is "Surface waves." Rayleigh waves are a type of surface wave that travel along the surface of a material with an elliptical motion, causing both longitudinal and transverse particle motion. They are commonly encountered in ultrasonic testing and other nondestructive testing methods, particularly when inspecting the surface or near-surface regions of materials.

Question 7: A material used between the face of a transducer and the test surface to permit or improve the transmission of ultrasonic vibrations from the transducer to the material being tested is called:

A wetting agent
A couplant (Correct answer)
An acoustic transmitter
A lubricant

Correct answer: A couplant

Explanation: A material used between the face of a transducer and the test surface to permit or improve the transmission of ultrasonic vibrations from the transducer to the material being tested is called a "couplant." Couplants are typically gel-like substances, oils, or greases that help to ensure the efficient transfer of ultrasonic energy between the transducer and the test piece, enhancing the accuracy of ultrasonic inspections.

Question 8: The piezoelectric material in a transducer that vibrates to produce ultrasonic waves is called a:

Backing material
Lucite wedge
Crystal (Correct answer)
Couplant

Correct answer: Crystal

Explanation: The piezoelectric material in a transducer that vibrates to produce ultrasonic waves is called a "Crystal." Piezoelectric crystals convert electrical energy into mechanical vibrations and vice versa when subjected to an electric field, making them essential components of ultrasonic transducers.

Question 9: The transducer that contains the thinnest piezoelectric crystal is a:

1 MHz transducer
5 MHz transducer
15 MHz transducer
25 MHz transducer (Correct answer)

Correct answer: 25 MHz transducer

Explanation: The frequency of an ultrasonic transducer is inversely proportional to the thickness of the piezoelectric crystal it contains. Therefore, a 25 MHz transducer would typically contain the thinnest piezoelectric crystal among the options provided. Higher frequency transducers, such as 25 MHz, have thinner crystals compared to lower frequency transducers like 1 MHz.

Question 10: A 25 MHz transducer would most likely be used during:

Straight beam contact testing
Immersion testing (Correct answer)
Angle beam contact testing
Surface wave contact testing

Correct answer: Immersion testing

Explanation: Higher frequency transducers, such as a 25 MHz transducer, are typically used in immersion testing. Immersion testing involves submerging the transducer and the test object in a liquid coupling medium, allowing for efficient transmission of high-frequency sound waves into the material. This method is commonly used for inspecting thin materials or detecting fine surface and subsurface defects.

Question 11: The amount of beam divergence from a crystal is primarily dependent on the:

Type of test
Tightness of crystal backing in the transducer
Frequency and crystal size (Correct answer)
Pulse length

Correct answer: Frequency and crystal size

Explanation: The amount of beam divergence from a crystal is primarily dependent on the frequency and size of the crystal. Higher-frequency crystals and smaller crystal sizes tend to produce narrower beam divergence, while lower-frequency crystals and larger crystal sizes result in broader beam divergence.

Free ASNT Ultrasonic Questions and Answers

The indication on the instrument display that represents the far boundary of the material being tested is called: