Sonography Canada CORE (Physics) Questions With Correct Answers(Latest Update 2023).

what is a transducer? -ANSWER anything that converts one form of energy to another form of energy what does an ultrasound transducer do? -ANSWER converts electropotential energy into mechanical and mechanical energy into electropotential energy what is the curie point? -ANSWER if a crystal is heated beyond the curie point (360 degrees for PZT) the crystal can lose piezoelectric effects what material is traditionally used for ultrasound trasnducers? -ANSWER Lead ziconate titanate (PZT) what are modern transducers made out of? -ANSWER composite materials to achieve greater conversion efficiency with less of an acoustic impedance mismatch Near zone (fresnel) -ANSWER the area between the face of the transducer and the beam focus Far zone (Fraunhofer) -ANSWER Region past the focus Focus -ANSWER Where the beam reaches its minimum diameter Focal region -ANSWER Region over whch the beam is most tightly focused Detail resolution -ANSWER Ability to distinguish between two objects in any of the three dimensions (Axial,lateral, elevational) Operating frequency -ANSWER Center frequency of the transmit bandwidth what are four methods of focusing the ultrasound beam -ANSWER 1)Lenses 2)curved elements 3)electronic focusing 4)mirrors define lateral resolution. What are other names for lateral resolution? -ANSWER The ability to resolve two structures as well as the limit to measurement accuracy in the lateral dimension of an image Side by side, angular, transverse, azimuthal Lateral resolution is equal to.... -ANSWER Lateral bandwidth define elevation resolution. What are other names -ANSWER ability to resolve two structures as well as the limit to measurement accuracy in the elevation dimension what are the four acoustic variables? -ANSWER Pressure density temperature particle motion If a wave needs a medium to propagate it is a(n) __________ wave? -ANSWER mechanical what is the wavelength equation -ANSWER wavelength=propagation velocity/frequency What is amplitude? -ANSWER measure of the strength or size of a physical quantity. V