Davies SPI - US Physics| 113 questions| verified answers

You have decreased the acoustic power by -3 dB. Which of the following most accurately describes this adjustment? A. Intensity has been quadrupled B. Intensity has been quartered C. Intensity has been increased 10 times D. Intensity has been halved E. Intensity has not been altered CORRECT ANSWERS: D. Intensity has been halved intensity change of 3 dB corresponds to a doubling of the intensity. if it's changed by -3 dB, intensity is halved. When you switch from a 2.5 MHz to a 5 MHz transducer, the sound wavelength: A. Doubles B. Quadruples C. Halves D. Quarters E. Is unaffected CORRECT ANSWERS: C. Halves wavelength inversely proportional to frequency. The mass you are imaging has a diameter of 35 mm. This value can also be expressed as: A. 350 cm B. 0.35 cm C. 3.5 cm D. 35 m E. 3.5 m CORRECT ANSWERS: C. 3.5 cm Which phenomenon is associated with a pattern produced by a sound beam after passing through a small aperture? A. Scattering B. Absorption C. Diffraction D. Interference E. Diffuse reflection CORRECT ANSWERS: C. Diffraction diffraction is the general term for various phenomena in which waves from different parts of a source add or subtract Choose two benefits of tissue harmonic imaging. A. Grating lobe artifacts are reduced and lateral resolution is improved. B. Axial and lateral resolutions are improved.