Lesson 2 Quiz UT Flashcards
- By changing the transducer, the ultrasonic testing technician could change the testing:
Frequency, Different transducers operate at different frequencies, so by changing the transducer, the technician can alter the frequency used during the test.
- Another name for a longitudinal wave is:
Compression Wave, Longitudinal waves are also known as compression waves because they cause particles in the material to compress and expand in the direction of wave propagation.
- The velocity of a longitudinal wave is:
About twice the velocity of a shear wave in steel, Longitudinal waves travel faster than shear waves. In steel, the velocity of longitudinal wave is approximately twice that of a shear wave.
- Surface waves travel at about 10% less than:
Shear waves, Surface waves travel slightly slower than shear waves, which are transverse waves that propagate within a material.
- In ultrasonic testing, the term attenuation is closely connected to:
Damping, Attenuation refers to the reduction in amplitude or intensity of the sound wave as it travels through the material, which is closely linked to damping.
- When wave energy is lost through reflection and scattering of the beam within the material, it is understood that _______ is occurring.
Attenuation, Attenuation occurs when wave energy decreases due to scattering, reflection, or absorption as the wave travels through a material.
- The opposition of a material to the passage of a sound wave is called:
Acoustic impedance, Acoustic impedance is the resistance a material presents to the passage of a sound wave. It is a function of the material’s density and sound velocity.
- Acoustical impedance of a given material is derived by material density:
Multiplied by sound velocity, Acoustic impedance is the product of the material’s density and the velocity of sound throuth the matierial. It is a key factor in determining the reflection and t6ransmission of sound at interfaces.
- The higher the ratio of acoustic impedance, the:
Mismatch, An impedance mismatch occurs when two materials have very different acoustic impedances, causing more reflection of sound waves at all boundrary.
- A higher impedance ratio is often called impedance:
Mismatch, An impedance mismatch occurs when two materials have very diffrent acoustic impedances, causing more reflection of sound waves at the boundary.
- In ultrasound, the term refraction refers to _________ of the sound beam as it passes from one medium to another.
Bending, Refraction refers to the change in direction (or bending) of a sound wave as it passes from one medium to another with a diffrent veloci8ty of sound.
- Refraction and mode conversion occur because the _________ of the longitudinal wave changes as the beam enters the second medium.
Speed, The speed of the wave changes when it enters a medium with a different density and elastic properties, causing refraction and potentially mode converasation.
- The velocity of shear waves is approximately ___________ that of compression waves.
Half, Shear waves typically travel at around half the speed of longitudinal (compression) waves in the same material.
- Snell’s law can be used to calculate angular relationships and :
Velocity measurements, Snell’s law relates the angles of incidence and refraction to the velocities of waves in different media, allowing for the calculatioon of wave velocity changes between materials.
- The relative amount of ultrasonic energy transmitted through a solid boundary interface in a test object depends primarily on:
The relative acoustic impedances of the materials on either side of the interface, The amount of energy transmitted or reflected at a boundary between two materials depends on the difference intheir acoustic impedances.
