SPI Practice Test| 175 QUESTIONS| WITH COMPLETE SOLUTIONS

Which of the following do the source and the medium determine? a. duty factor b. frequency c. propagation speed d. axial resolution CORRECT ANSWERS: d. Axial resolution is affected by all of the following EXCEPT a. frequency b. damping c. spatial pulse length d. focusing CORRECT ANSWERS: d. Damping in a transducer a. reduces the number of cycles in a pulse and increases the quality factor b. increases the number of cycles in a pulse and increases penetration c. causes poor axial and lateral resolution d. reduces the duty factor and increases the range of transmitted frequencies CORRECT ANSWERS: d. Far zone beam divergence can be reduced on a single-element transducer by using a. a transducer with a smaller element diameter b. a higher frequency transducer c. a lower frequency transducer or a smaller element diameter d. adjustable focusing CORRECT ANSWERS: b. The area between the face of an unfocused single-element transducer and the point where the beam starts to diverge is the a. Fraunhofer zone b. refraction zone c. focal zone d. near zone CORRECT ANSWERS: d. Assuming a fixed frequency, what happens if the diameter of an unfocused transducer is increased? a. the far zone divergence increases b. the penetration decreases c. the length of the near zone increases