What is dynamic aperture? A.aperture that varies with transmit frequency B.aperture that decreases as a function of time C.aperture that increases with increasing focal length D.aperture that changes as a function of frame rate. C - Answer A - Answer to which acoustic variable is penetration depth inversely related? A.frequency B.wavelength C.period D.propagation speed B - Answer which imaging mode requires a broadband transducer? A.continuous wave doppler B.Pulsed wave doppler C.color flow imaging D.harmonic imaging B - Answer what is the doppler shift frequency? A.recieved ultrasound frequency multiplied by the transmitted ultrasound frequency B.difference between the transmitted ultrasound frequency and the received ultrasound frequency C.sum of the transmitted and received ultrasound frequencies D.ratio of the transmitted ultrasound frequency to the received ultrasound frequency A - Answer what is the potential effect of increasing the pulse repetition frequency(PRF)? A.Depth ambiguity B.Decreased frame rate C.Poor spatial resolution D.Decreased penetration B - Answer what is an advantage of using pulsed wave doppler compared to continuous wave doppler? A.higher echo sensitivity B.ability to select sample depth C.decreased display of aliasing D.improved temporal resolution D - Answer what affects the beam width in the near field? A.Pulse repetition frequency