<prompt> Which of the following techniques use piezoelectric crystals -UltrasonographyX-ray diffractionNMR imagingXeroradiography  <response>: Ans. is a i.e., Ultrasonography o Ultrasonography is based on piezoelectric effect.o MRI is based on gyeromagneticproperty of proton H.Ultrasonography USG Ultrasoundo USG is performed with the pulse-echo technique. By the virtue of piezoelectric effect in the ultrasound probe or transducer, electric energy is converted to sound energy that is transmitted into patients tissues. The US transducer probe then becomes a receiver, detecting echo of sound energy reflected from tissue.o The US transducer probe then becomes a receiver, detecting echo of sound energy reflected from tissue.o The ultrasound transducer uses the principle or property of piezoelectricity.o Quartz is a naturally occuring peizoelectric material.o Currently, Lead Zirconate titanate PZT is the most widely used material in the ultrasound tranducerprobes 