# Physics-Sound Beams

 The flashcards below were created by user aprilh4485 on FreezingBlue Flashcards. What is the best estimate of the diameter or width of the sound beam as it exits the transducer? 12 mm What is the diameter of the sound beam at a depth of 8 cm? 6 mm What is the diameter of the sound beam at a depth of 16 cm? 12 mm At what depth is the focus? 8 cm What depth marks the beginning of the focal zone? 6 cm What depth marks the end of the focal zone? 10 cm At which of the following depths is the beam narrowing? A. 8 cm B. 9 cm C. 6 cm D. 10 cm E. 12 cm C. 6 cm(this multiple choice question has been scrambled) At which of the following depths is the beam widening? A. 6 cm B. 4 cm C. 9 cm D. 2 cm E. 8 cm C. 9 cm(this multiple choice question has been scrambled) At which of the following depths is the beam most likely to have the same diameter as it has at a depth of 11 cm? A. 1 cm B. 8 cm C. 14 cm D. 3 cm E. 5 cm E. 5 cm(this multiple choice question has been scrambled) A pair of 6 MHz probes are identical except for active element diameter. The active element diameters are 6 mm and 10 mm, respectively. The sound beam of which probe will have a shallower focus? the probe with a 6 mm active element has a shallower focus. A pair of 9 mm diameter probes are identical except for frequency, which is 3 MHz and 6 MHz, respectively. Which beam will have a shallower focus? 3 MHz Which of the following probes creates a beam with the deepest focus? A. 4 mm diameter, 4 MHz B. 6 mm diameter, 8 MHz C. 6 mm diameter, 2 MHz d. 5 mm diameter, 8 MHz B. 6 mm diameter, 8 MHzit has the biggest diameter and highest frequency, so it creates a beam with the deepest focus Which of the following probes creates a beam with the shallowest focus? A. 4 mm diameter, 4 MHz B. 6 mm diameter, 8 MHz C. 4 mm diameter, 2 MHz D. 5 mm diameter, 8 MHz C. 4 mm diameter, 2 MHzit has smallest diameter and lowest frequency, so it creates a beam with the shallowest focus True or False. Transducer frequency and near zone length are inversely related? falsethey are directly related True or False. Wavelength and near zone length are inversely related? True. True or False. Active element diameter and near zone length are directly related. True A pair of 6 MHz probes are identical except for active element diameter, which is 6 mm and 10 mm, respectively. Which beam will be more compact in the far field? the transducer with the 10 mm active element A pair of 9 mm diameter probes are identical except for frequency, which are 3 MHz and 6 MHz. Which sound beam will spread out more in the far field? 3 MHz beam is more divergent Which of the following probes creates a beam with the least divergence? A. 4 mm diameter, 4 MHz B. 6 mm diameter, 8 MHz C. 6 mm diameter, 2 MHz D. 5 mm diameter, 8 MHz B. 6 mm diameter, 8 MHzdivergence is minimized with large diameter, high frequency probes. Which of the following probes creates a beam with the most divergence? A. 4 mm diameter, 4 MHz B. 6 mm diameter, 8 MHz C. 4 mm diameter, 2 MHz D. 5 mm diameter, 8 MHz C. 4 mm diameter, 2 MHzdivergence is pronounced with small diameter, low frequency probes True or False. Transducer frequency and beam divergence are inversely related. True True or False. Active element diameter and beam divergence are inversely related. True What is the lateral resolution at a depth of 8 cm? 4.5 mm What is the lateral resolution at a depth of 16 cm? 9 mm What is the best estimate for the resolution at 4 cm? A. 15 mm B. 5 mm C. 9 mm D. 1 cm B. 5 mm(this multiple choice question has been scrambled) What is the best estimate for the resolution at 7 cm? A. 1 cm B. 14 mm C. 9 mm D. 5 mm D. 5 mm(this multiple choice question has been scrambled) What is the best estimate for the resolution at 21 cm? A. 1 cm B. 14 mm C. 5 mm D. 9 mm B. 14 mm(this multiple choice question has been scrambled) The ability to distinguish two structures lying close together is called __________. resolution The ability to distinguish two structures lying close together front-to-back is called __________. LARRD - longitudinal, axial, range, radial, or depth resolution The ability to distinguish two structures lying close together side by side is called __________. LATA - lateral, angular, transverse, or azimuthal resolution Axial resolution and lateral resolution are both measured with units of _________. distance; mm or cm When the number of cycles in a pulse increases while the frequency remains the same, the numerical value of the range resolution __________. (increases, decreases, remains the same) increaseswith more cycles in a pulse, the pulse becomes longer and the numerical value of the range resolution increases When the number of cycles in a pulse increases (more ringing) while the frequency remains the same, the numerical value of the range resolution ___________. (improves, degrades, remains the same) degradeswhen # of cycles increases, the spatial pulse length increases and the image quality degrades ___________ frequency transducers have the best range resolution. (high, low) high Name the 4 synonyms for axial resolution longitudinal, range, radial, depth Name the 3 synonyms for lateral resolution. angular, transverse, azimuthal The length of a pulse is 8 mm. What is the minimum distance between two reflectors, positioned one in front of the other, that still produces two echoes on our image? A. 8 mm B. 4 mm C. 16 mm D. 2 mm E. cannot be determined B. 4 mm one half the pulse length The frequency of a transducer does not change. If the diameter of the new piezoelectric crystal increases, what happens to the near zone length? increases The frequency of a transducer does not change. If the diameter of the new piezoelectric crystal increases, waht happens to the beam diameter in the far zone? decreases The frequency of a transducer does not change. If the diameter of the new piezoelectric crystal increases, what happens to the wavelength? no change. The frequency of a transducer does not change. If the diameter of the new piezoelectric crystal increases, what happens to the beam diameter in the near zone? increases Which of the following transducers has the best lateral resolution deep in the far zone? A. lowest frequency, largest crystal diameter B. highest frequency, largest crystal diameter C. lowest frequency, smallest crystal diameter D. highest frequency, smallest crystal diameter B.narrow beams improve lateral resolution; highest frequency and largest diameter produces the narrowest beam. Which of the following transducers has the best lateral resolution deep in the far field? A. 4 MHz, 4 mm crystal diameter B. 6 MHz, 4 mm crystal diameter C. 4 MHz, 6 mm crystal diameter D. 6 MHz, 6 mm crystal diameter D. highest frequency and largest diameter creates narrowest beam which have best lateral resolution in the far field Authoraprilh4485 ID115941 Card SetPhysics-Sound Beams DescriptionSound Beams Updated2011-11-11T04:11:07Z Show Answers